Pyrogallol

Carcinogenicity

Description of key information

The data which suggest a carcinogenic effect are limited. Moreover, the substance increases the incidence of lesions of uncertain neoplastic potential ( Squamous epithelial hyperplasia, accompaigned by hyperketarosis). Also, differnet results are found in different species.

Key value for chemical safety assessment

Carcinogenicity: via oral route

Link to relevant study records

Reference

Reference 1

Endpoint:

carcinogenicity: dermal

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Qualifier:

no guideline available

Principles of method if other than guideline:

- Principle of test:
- Short description of test conditions:
- Parameters analysed / observed:

GLP compliance:

not specified

Species:

mouse

Strain:

other: ICR/Ha Swiss

Details on species / strain selection:

no data

Sex:

female

Details on test animals or test system and environmental conditions:

no data

Route of administration:

dermal

Vehicle:

acetone

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

440 days

Frequency of treatment:

three times weekly

Dose / conc.:

0.5 other: microg

No. of animals per sex per dose:

50

Control animals:

yes

Details on study design:

no data

Positive control:

no data

Observations and examinations performed and frequency:

Tumors (> 1 mm in diameter) persisting for 30 days or more were recorded.

Sacrifice and pathology:

All animals were necropsied, and specimens of neoplasms were examined microscopically.

Other examinations:

no data

Statistics:

no data

Histopathological findings: neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Ten of the 50 mice treated with benzo[a]pyrene developed squamous carcinomas, whereas 33 of the 50 mice treated with benzo[a]pyrene and Pyrogallol developed squamous carcinomas.
No neoplasms were observed in the mice treated with Pyrogallol alone.

Conclusions:

The co-carcinogenicity of Pyrogallol was evaluated using 50 female ICR/Ha Swiss mice (6-8 weeks old). Pyrogallol (5 mg in acetone) and benzo[a]pyrene (5microg/0,1 ml acetone) were applied simultaneously to clipped dorsal skin three times weekly for 440 days. The control group (50 mice) was treated with benzo[a]pyrene according to the same procedure. Tumors (> 1 mm in diameter) persisting for 30 days or more were recorded. Animals with carcinomas were killed when moribund or approximately 2 months after tumors were clinically classified as malignant. All animals were necropsied, and specimens of neoplasms were examined microscopically. Ten of the 50 mice treated with benzo[a]pyrene developed squamous carcinomas, whereas 33 of the 50 mice treated with benzo[a]pyrene and Pyrogallol developed squamous carcinomas.
No neoplasms were observed in the mice treated with Pyrogallol alone.

Executive summary:

A series of 21 tobacco smoke components and related compounds werere applied to mouse skin (50 female ICR/Ha Swiss mice/group) three times weekly with a low dose (5 mug/application) of benzo[a]pyrene (B[a]P). The test compounds were of five classes: aliphatic hydrocarbons, aromatic hydrocarbons, phenols, and long-chain acids and alcohols. The following compounds enhanced remarkably the carcinogenicity of B[a]P: catechol, pyrogallol, decane, undecane, pyrene, benzo[e]pyrene, and fluoranthene. The following compounds inhibited B[a]P carcinogenicity completely: esculin, quercetin, squalene, and oleic acid. Phenol, eugenol, resorcinol, hydroquinone, hexadecane, and limonene partially inhibited B[a]P carcinogenicity. Six of the 21 compounds were also tested as tumor promoters im two-stage carcinogenesis. No direct correlation existed between tumor-promoting activity and carcinogenic activity. The cocarcinogens pyrogallol and catechol did not show tumor-promoting activity. Decane, tetradecane, anthralin, and phorbol myristate acetate showed both types of activity. Structure-activity relationships and possible modes of action were described.

Reference 2

Endpoint:

carcinogenicity: dermal

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline available

Principles of method if other than guideline:

- Principle of test:
- Short description of test conditions:
- Parameters analysed / observed:

GLP compliance:

not specified

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material:
- Expiration date of the lot/batch:
- Purity test date:

RADIOLABELLING INFORMATION (if applicable)
- Radiochemical purity:
- Specific activity:
- Locations of the label:
- Expiration date of radiochemical substance:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material:
- Stability under test conditions:
- Solubility and stability of the test substance in the solvent/vehicle:
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium:

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing:
- Preliminary purification step (if any):
- Final dilution of a dissolved solid, stock liquid or gel:
- Final preparation of a solid:

FORM AS APPLIED IN THE TEST (if different from that of starting material)

TYPE OF BIOCIDE/PESTICIDE FORMULATION (if applicable)

OTHER SPECIFICS:

Species:

mouse

Strain:

Swiss

Details on species / strain selection:

Eppley Swiss

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source:
- Females (if applicable) nulliparous and non-pregnant: [yes/no]
- Age at study initiation: 6 weeks old
- Weight at study initiation:
- Fasting period before study:
- Housing:
- Diet (e.g. ad libitum):
- Water (e.g. ad libitum):
- Acclimation period:

DETAILS OF FOOD AND WATER QUALITY:

ENVIRONMENTAL CONDITIONS
- Temperature (°C):
- Humidity (%):
- Air changes (per hr):
- Photoperiod (hrs dark / hrs light):

IN-LIFE DATES: From: To:

Route of administration:

dermal

Vehicle:

not specified

Details on exposure:

0.05 ml (of hair dye formulation) per mouse per application

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

An aliquot of 0.05 ml was delivered from a calibrated Hamilton syringe

Duration of treatment / exposure:

Treatments were carried out for 20 months followed by terminal sacrifice

Frequency of treatment:

skin painted up to 3 times weekly

Post exposure period:

Nine months after treatments were initiated an intermediate sacrifice of ten mice per sex per group was carried out.

Dose / conc.:

0.49 other: %

Remarks:

concentration of Pyrogallol in the formulation

No. of animals per sex per dose:

60 male and 60 female

Control animals:

yes

Details on study design:

an area of skin in the interscapular region clipped free of hair and approxicmately 1 sq. cm. in area

Observations and examinations performed and frequency:

After 9 months of treatment, 10 males and 10 females were selected randomly from each group for clinical tests, hematology, and necropsy. Urine samples were analyzed for color, pH, occult blood, albumin, and glucose. Blood samples were obtained via cardiac puncture, and complete blood counts and differential white cell counts were determined.
At 20 months posttreatment, the remaining animals were killed for necropsy. At the time of necropsy, complete and differential cell counts were performed on blood samples from 10 mice (5 males, 5 females) per group. Results from analyses of the blood and urine indicated no treatment-related effects. Pulmonary adenomas, hepatic hemangiomas, and malignant lymphomas were observed in experimental and control groups.

Statistics:

Statistical analyses, chi-square and Fisher exact tests, of the incidence of hepatic hemangiomas, pulmonary adenomas, and malignant lymphomas

Clinical signs:

not examined

Dermal irritation (if dermal study):

effects observed, treatment-related

Description (incidence and severity):

Microscopic examinations of the skin revealed occasional hyperplasia, necrosis, ulceration and other lesions not significantly increased by dye treatment

Mortality:

mortality observed, treatment-related

Description (incidence):

survival differed little between appropriate male and female treatment and control groups.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Body weights differed little between appropriate male and female treatment and control groups.

Food efficiency:

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

Differences between treated and control groups in hematologicalmvalues were not considered to be indicative of toxicologic effects

Clinical biochemistry findings:

not examined

Urinalysis findings:

effects observed, treatment-related

Description (incidence and severity):

Differences between treated and control groups in urinary values were not considered to be indicative of toxicologic effects

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

Differences between treated and control groups in absolute and relative liver and kidney weights were not considered to be indicative of toxicologic effects

Gross pathological findings:

not examined

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

effects observed, treatment-related

Description (incidence and severity):

The predominant tumors diagnosed were liver hemangioma, lung adenoma and malignant lymphoma.

Other effects:

not examined

Relevance of carcinogenic effects / potential:

There was a statistically significant increase in the incidence of malignant lymphoma in female mice in 3 treated groups when compared to control group 2, but the differences were not significant when these groups were compared to control group 1. In addition the values in these 3 groups were within the range of control values for this tumor in female mice in the Eppley colony. No other tumors occurred at significantly increased frequencies in treated mice. We conclude that toxicological and carcinogenic effects were not clearly induced by the hair dye formulations

Conclusions:

The carcinogenicity of an oxidative hair dye formulation containing 0.49% Pyrogallol was evaluated using random-bred Swiss mice (6 weeks old). The experimental group and the two untreated control groups each contained 60 male and 60 female mice. Treatment was initiated when the mice were 8 weeks old. The dye was mixed with an equal volume of 6% H2O2 and applied (0.5 ml per application) once per week for a period of 20 months. Applications were made via a calibrated syringe to an area of skin, clipped free of hair, in the interscapular region. After 9 months of treatment, 10 males and 10 females were selected randomly from each group for clinical tests, hematology, and necropsy. Urine samples were analyzed for color, pH, occult blood, albumin, and glucose. Blood samples were obtained via cardiac puncture, and complete blood counts and differential white cell counts were determined.
At 20 months posttreatment, the remaining animals were killed for necropsy. At the time of necropsy, complete and differential cell counts were performed on blood samples from 10 mice (5 males, 5 females) per group. Results from analyses of the blood and urine indicated no treatment-related effects. Pulmonary adenomas, hepatic hemangiomas, and malignant lymphomas were observed in experimental and control groups. Statistical analyses, chi-square and Fisher exact tests, of the incidence of hepatic hemangiomas, pulmonary adenomas, and malignant lymphomas indicated no significant differences between experimental and control groups

Executive summary:

The chronic toxicologic and carcinogenic potential of two oxidative and twelve non-oxidative hair dyes has been evaluated. The dyes were skin painted up to 3 times weekly on groups of 60 male and 60 female Eppley Swiss mice. Treatments were carried out for 20 months followed by terminal sacrifice. Nine months after treatments were initiated an intermediate sacrifice of ten mice per sex per group was carried out. Body weights and survival differed little between appropriate male and female treatment and control groups. Differences between treated and control groups in absolute and relative liver and kidney weights and in hematological and urinary values were not considered to be indicative of toxicologic effects. Microscopic examinations of the skin revealed occasional hyperplasia, necrosis, ulceration and other lesions not significantly increased by dye treatment. Chronic inflammation of the skin was observed in the control and treated mice and was significantly increased by one non-oxidative dye. The predominant tumors diagnosed were liver hemangioma, lung adenoma and malignant lymphoma. There was a statistically significant increase in the incidence of malignant lymphoma in female mice in 3 treated groups when compared to control group 2, but the differences were not significant when these groups were compared to control group 1. In addition the values in these 3 groups were within the range of control values for this tumor in female mice in the Eppley colony. No other tumors occurred at significantly increased frequencies in treated mice. We conclude that toxicological and carcinogenic effects were not clearly induced by the hair dye formulations.

Reference 3

Endpoint:

carcinogenicity: dermal

Type of information:

experimental study

Adequacy of study:

disregarded due to major methodological deficiencies

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

significant methodological deficiencies

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test:
Pyrogallol (CAS No. 87-66-1), a benzenetriol used historically as a hair dye and currently in a number of industrial applications, was studied in a 2-year- study in order to evaluate carcinogenicity effects when applied to naïve skin (i.e. dermal administration) to mice. In a previous 3-months-study, adult rodents were administered the substance in order to fill the lack of knowledge regarding the toxicity effect of the substance.
- Short description of test condition: a dermal administration of the substance were performed to male and female mice for 2-years.
- Parameters analysed / observed: neoplastic e non-neoplastic effects were analysed; The incidence of squamous cell carcinoma at the site of application (SOA) in 75 mg/kg female mice and SOA squamous cell papillomas in 75 mg/kg male mice were greater than controls. Pyrogallol was carcinogenic in female mice and may have caused tumors in male mice.

GLP compliance:

yes

Remarks:

These studies were conducted in compliance with FDA Good Laboratory Practice for nonclinical laboratory studies (21 CFR 58).

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material:
Pyrogallol was obtained from Aceto Corporation (Lake Success, NY; lot number 010326).
- Expiration date of the lot/batch:
not specified
- Purity test date:
Purity was determined by high-performance liquid chromatography with ultraviolet detection to be greater than 99%.

RADIOLABELLING INFORMATION (if applicable)
- Radiochemical purity:
not applicable
- Specific activity:
not applicable
- Locations of the label:
not applicable
- Expiration date of radiochemical substance:
not applicable

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material:
not specified
- Stability under test conditions:
not specified
- Solubility and stability of the test substance in the solvent/vehicle:
not specified
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium:
not specified

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing:
not specified
- Preliminary purification step (if any):
not specified
- Final dilution of a dissolved solid, stock liquid or gel:
not specified
- Final preparation of a solid:
not specified

FORM AS APPLIED IN THE TEST (if different from that of starting material)

TYPE OF BIOCIDE/PESTICIDE FORMULATION (if applicable)
: not applicable

OTHER SPECIFICS: Dose formulations were prepared by mixing pyrogallol and95% ethanol to give the required concentrations. Dose formulations were analyzed three times during the subchronic study and every three months during the chronic study and were within 10% of target pyrogallol concentrations.

Species:

mouse

Strain:

B6C3F1

Details on species / strain selection:

not specified

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source:
obtained from Taconic Farms, Inc. (Germantown, NY)
- Females (if applicable) nulliparous and non-pregnant: [yes/no]
not specified
- Age at study initiation:
rats were 6–8 weeks old
- Weight at study initiation:
not specified
- Fasting period before study:
not specified
- Housing:
housed individually
- Diet (e.g. ad libitum):
Irradiated NTP-2000 wafer feed (Zeigler Brothers, Inc., Gardners, PA) was available ad libitum.
- Water (e.g. ad libitum):
tap water (Columbus, OH, municipal supply) was available ad libitum.
- Acclimation period:
quarantined for 14 days

DETAILS OF FOOD AND WATER QUALITY:
see above

ENVIRONMENTAL CONDITIONS
- Temperature (°C):
not specified
- Humidity (%):
not specified
- Air changes (per hr):
not specified
- Photoperiod (hrs dark / hrs light):
not specified

IN-LIFE DATES: From: To: not specified

Animal care and use were in accordance with the Laboratory Animal Welfare Act of 1966 (P.L. 89–544) as amended and the Public Health Service Policy on Humane Care and Use of Animals. Animals were treated humanely and with regard for alleviation of pain and distress. All animals were housed in facilities accredited by the Association for Assessment and Accreditation of Laboratory Animal Care and all procedures were approved by Battelle's Institutional Animal Care and Use Committee.

Route of administration:

dermal

Vehicle:

ethanol

Details on exposure:

TEST SITE
- Area of exposure: Pyrogallol was administered over the application site with a Corning Lambda (Corning, Inc., Corning, NY) single channel pipetter with a disposable polyethylene tip
- % coverage: not specified
- Type of wrap if used: -
- Time intervals for shavings or clipplings: An area slightly larger than the interscapular application site was clipped 24 hours before the first dose and weekly thereafter.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): not specified
- Time after start of exposure: not specified

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): Dosing volumes were 2.0 mL/kg body weight
- Concentration (if solution):
- Constant volume or concentration used: yes
- For solids, paste formed: not applicable

VEHICLE
- Justification for use and choice of vehicle (if other than water):
- Amount(s) applied (volume or weight with unit):
- Concentration (if solution):
- Lot/batch no. (if required):
- Purity:

USE OF RESTRAINERS FOR PREVENTING INGESTION: not specified

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

105 weeks

Frequency of treatment:

5 days per week

Post exposure period:

Body weights were recorded weekly for 13 weeks and monthly thereafter.

Dose / conc.:

0 other: mg/kg

Dose / conc.:

5 other: mg/kg

Remarks:

pyrogallol in 95% ethanol

Dose / conc.:

20 other: mg/kg

Remarks:

pyrogallol in 95% ethanol

Dose / conc.:

75 other: mg/kg

Remarks:

pyrogallol in 95% ethanol

No. of animals per sex per dose:

Groups of 50 male and 50 female

Control animals:

yes, concurrent vehicle

Details on study design:

- Toxicokinetic data : not specified
- Dose selection rationale: Dose was limited by the maximum solubility of pyrogallol in the 95% ethanol vehicle (300 mg/mL) and the fixed dosing volumes used (0.5 mL/kg rats, 2 mL/kg mice).
- Rationale for animal assignment (if not random): not specified
- Rationale for selecting satellite groups: not specified
- Post-exposure recovery period in satellite groups: not specified
- Section schedule rationale (if not random): not specified

Positive control:

no

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: no
- Time schedule: not applicable
- Cage side observations checked in table [No.?] were included. not applicable

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: clinical signs were recorded weekly

DERMAL IRRITATION (if dermal study): no
- Time schedule for examinations: not applicable

BODY WEIGHT: Yes
- Time schedule for examinations: recorded weekly.

FOOD CONSUMPTION: no
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: not applicable

FOOD EFFICIENCY: no
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: not applicable

WATER CONSUMPTION: no
- Time schedule for examinations: not applicable

OPHTHALMOSCOPIC EXAMINATION: no
- Time schedule for examinations: not applicable
- Dose groups that were examined: not applicable

HAEMATOLOGY: no
- Time schedule for collection of blood: not applicable
- Anaesthetic used for blood collection: not applicable
- Animals fasted: not applicable
- How many animals: not applicable
- Parameters checked in table [No.?] were examined. not applicable

CLINICAL CHEMISTRY: no
- Time schedule for collection of blood: not applicable
- Animals fasted: not applicable
- How many animals: not applicable
- Parameters checked in table [No.?] were examined. not applicable

URINALYSIS: no
- Time schedule for collection of urine: not applicable
- Metabolism cages used for collection of urine: not applicable
- Animals fasted: not applicable
- Parameters checked in table [No.?] were examined. not applicable

NEUROBEHAVIOURAL EXAMINATION: No
- Time schedule for examinations: not applicable
- Dose groups that were examined: not applicable
- Battery of functions tested: sensory activity / grip strength / motor activity / other: not applicable

OTHER: Weights of major organs were recorded at necropsy, including heart, liver, kidney, lung, testis, uterus, thymus and thyroid gland.

Animals were observed twice daily and clinical findings were recorded monthly beginning at week 5.n kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: Yes / No / No data

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Yes / No / No data
- Time schedule for examinations:

OPHTHALMOSCOPIC EXAMINATION: Yes / No / No data
- Time schedule for examinations:
- Dose groups that were examined:

HAEMATOLOGY: Yes / No / No data
- Time schedule for collection of blood:
- Anaesthetic used for blood collection: Yes (identity) / No / No data
- Animals fasted: Yes / No / No data
- How many animals:
- Parameters checked in table [No.?] were examined.

CLINICAL CHEMISTRY: Yes / No / No data
- Time schedule for collection of blood:
- Animals fasted: Yes / No / No data
- How many animals:
- Parameters checked in table [No.?] were examined.

URINALYSIS: Yes / No / No data
- Time schedule for collection of urine:
- Metabolism cages used for collection of urine: Yes / No / No data
- Animals fasted: Yes / No / No data
- Parameters checked in table [No.?] were examined.

NEUROBEHAVIOURAL EXAMINATION: Yes / No / No data
- Time schedule for examinations:
- Dose groups that were examined:
- Battery of functions tested: sensory activity / grip strength / motor activity / other:

OTHER:

Sacrifice and pathology:

not specified

Other examinations:

no other examinations were performed

Statistics:

To determine statistical differences between incidences, Fisher exact test and poly-3 test were used where applicable. Organ and body weight data were analyzed with the parametric multiple comparison procedures of Dunnett and Williams. Analysis of effects on survival used Cox's [25] method for testing two groups for equality and Tarone's life table test to identify dose-related trends

Clinical signs:

not examined

Dermal irritation (if dermal study):

effects observed, treatment-related

Description (incidence and severity):

Irritation and/or ulceration of the skin at the site of application were the only chemical-related clinical findings and occurred predominantly in the 20 and 75 mg/kg male and female groups.

Mortality:

mortality observed, non-treatment-related

Description (incidence):

Survival of dosed groups of male mice were similar to that of the vehicle control groups. However, survival of 75 mg/kg female mice was significantly decreased, as 23 female mice were euthanized before study end due to the presence of ulcers at the SOA (site of application). The mortality rate was very high in both control and treated group.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

mean body weights of dosed groups of male mice were similar to that of the vehicle control groups.

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not examined

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

The incidences of hyperplasia and hyperkeratosis were significantly greater than those in the vehicle control groups in most dosed groups of mice; incidences of inflammation were significantly increased in several groups treated with 20 or 75 mg/kg. Sebaceous gland hyperplasia was significantly increased in mice; mice developed pigmentation, fibrosis and ulcers.
Mice had moderate (7–8 layers) and marked (> 8 layers) hyperplasia.
Hyperplasia was usually accompanied by varying degrees of hyperkeratosis, which was characterized by increased layers of keratin overlying the epidermis. Hyperkeratosis was considered minimal if the keratin overlying the stratum granulosum was thin and loosely packed and mild when there was a thick, dense, compact band of keratin above the stratum granulosum. In the mice, the thickening of the stratum corneum occurred as both orthokeratotic and, to a lesser extent, parakeratotic hyperkeratosis.
In addition to the features, mice also displayed marked inflammation with low numbers of mast cells in the dermis and occasional infiltration into the subcutis or epidermis.
Sebaceous gland hyperplasia was of minimal to mild severity in mice, and was characterized by increased incidences with increased doses and increased size of the sebaceous glands; in mice this was concomitant with more frequent hair follicles.
Increased incidences of fibrosis and pigmentation were observed at 20 mg/kg and 75 mg/kg in male and female mice. Fibrosis was characterized by an increased presence of bands of pale, plump fibroblasts in the dermis. Pigmentation consisted of increased numbers of cells in the dermis containing abundant dark brown, granular, intracytoplasmic pigment considered to be melanin. Increased incidences of sebaceous gland hyperplasia and ulcers were observed at 75 mg/kg in males and females. Ulcer was characterized by fullthickness loss of epidermis and was invariably accompanied by necrosis and inflammation of the underlying dermis

Histopathological findings: neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Squamous cell carcinomas at the SOA were observed in four female mice exposed to 75 mg/kg pyrogallol

Other effects:

not examined

Details on results:

Squamous cell carcinomas at the SOA were observed in four female mice exposed to 75 mg/kg pyrogallol; none were observed in controls. Microscopically, squamous cell carcinomas were poorly demarcated, unencapsulated, invasive masses arising from the epidermis and extending into the underlying dermis and subcutis; the affected epidermis was ulcerated in some cases. Squamous cell carcinomas were composed of pleomorphic, disorganized proliferations of neoplastic squamous epithelial cells forming irregular cords and islands. The neoplastic epithelial cells often surrounded concentrically arranged aggregates of keratin (keratin pearls) and were surrounded by fibrous connective tissue infiltrated by neutrophils and other inflammatory cells.
Two 75 mg/kg male mice had grossly visible masses at the SOA that microscopically were identified as squamous cell papillomas; only one squamous cell papilloma has been observed in NTP historical control male mice in dermal application studies. One of the mice also had moderate inflammation at the SOA. The squamous cell papillomas were well-circumscribed, exophytic growths composed of an inner connective tissue core forming a stalk with superficial branching fronds that were covered by an outer layer of hyperplastic and hyperkeratotic squamous epithelium.

Dose descriptor:

dose level: neoplastic effects observed

Effect level:

75 other: mg/kg

Based on:

test mat.

Sex:

female

Basis for effect level:

histopathology: neoplastic

Dose descriptor:

dose level: neoplastic effect observed

Effect level:

75 other: mg/kg

Based on:

test mat.

Sex:

male

Basis for effect level:

histopathology: neoplastic

Critical effects observed:

yes

Lowest effective dose / conc.:

75 other: mg/kg

Organ:

skin

Treatment related:

yes

Dose response relationship:

not specified

Relevant for humans:

not specified

Skin lesions were consistently found at the SOA, a few dosed mice also had morphologically similar lesions in the skin of the neck and back immediately adjacent to the SOA. The incidences of hyperplasia, hyperkeratosis, ulcer, inflammation, and fibrosis at these sites were significantly increased in 75 mg/kg male and female mice. The incidences of sebaceous gland hyperplasia were also increased in 75 mg/kg mice, and the increase in females was significant. These lesions were considered related to the test material spreading to or beyond the margins of the clipped skin after application. One 75 mg/kg female had a squamous cell carcinoma of the skin of the right forelimb.

In this two-year study, female mice were more sensitive than males: treated mice groups showed significant increases in hyperkeratosis and inflammation at lower doses.

Mice treated for 2 years had additional increases in fibrosis and ulcers at the SOA.

Non-neoplastic dermal toxicity also led to decreased survival of female mice.

It shoud be noted that a significant increase in death was observed in female mice, which suggests that the systemic effects sseen are the result of unspecific toxicity.

Two types of neoplastic skin lesions of concern occurred at the SOA in mice: squamous cell papilloma in males and squamous cell carcinoma in females. The incidence of squamous cell papilloma at the SOA in 75 mg/kg male mice (2/50, 4%) was not statistically different from that in the vehicle control group (0/50); however, it exceeded the historical control ranges for 2-year ethanol dermal studies (0/200) and for all routes (1/1150). The incidence of squamous cell carcinoma of the skin at the SOA was significantly increased in 75 mg/kg female mice (4/50, 8%) when compared to the vehicle controls (0/50). In fact, no squamous cell carcinomas have been observed in NTP historical control female mice in dermal studies regardless of route or vehicle (0/1198).

The available experimental data suggest pyrogallol acts as a tumor promoter.

There were dose-related, significantly increased incidences of squamous epithelial hyperplasia at the site of application in all dose groups of male and female mice. Squamous epithelial hyperplasia is considered a pre-neoplastic lesion in mice.

However, relatively few squamous epithelial neoplastic lesions were observed in the skin.

Conclusions:

Skin at the SOA was the primary site of toxicity for pyrogallol for the 2-year dosing paradigms.
Pyrogallol was considered to be carcinogenic in female mice. In male mice, the presence of two rare benign tumors at the SOA in the high dose group was considered an equivocal finding.

Executive summary:

Pyrogallol (CAS No. 87-66-1), a benzenetriol used historically as a hair dye and currently in a number of industrial applications, was nominated to the National Toxicology Program (NTP) for testing based on lack of toxicity and carcinogenicity data. Three-month and two-year toxicity studies to determine the toxicity and carcinogenicity of pyrogallol when applied to naïve skin (i.e. dermal administration) were conducted in both sexes of F344/N rats and B6C3F1/N mice. In the three-month studies, adult rodents were administered pyrogallol in 95% ethanol 5 days per week for 3 months at doses of up to 150 mg /kg body weight (rats) or 600 mg/kg (mice). Based on the subchronic studies, the doses for the 2-year studies in rats and mice were 5, 20 and 75 mg/kg of pyrogallol. All mice and most rats survived until the end of the three-month study and body weights were comparable to controls. During the 2-year study, survival of dosed rats and male mice was comparable to controls; however survival of 75 mg/kg female mice was significantly decreased compared to controls. The incidences of microscopic non-neoplastic lesions at the site of application were significantly higher in all dosed groups of rats and mice and in both the 3 months and 2-year studies. In the 2-year study, hyperplasia, hyperkeratosis and inflammation tended to be more severe in mice than in rats, and in the mice they tended to be more severe in females than in males. The incidence of squamous cell carcinoma at the site of application (SOA) in 75 mg/kg female mice and SOA squamous cell papillomas in 75 mg/kg male mice were greater than controls. Pyrogallol was carcinogenic in female mice and may have caused tumors in male mice.

Reference 4

Endpoint:

carcinogenicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

no guideline available

Principles of method if other than guideline:

- Principle of test: Pyrogallol (CAS No. 87-66-1), a benzenetriol used historically as a hair dye and currently in a number of industrial applications, was studied in a 2 year study in order to evaluate carcinogenicity effects when applied to naïve skin (i.e. dermal administration) to rats. In a previous 3-months-study, adult rodents were administered the substance in order to fill the lack of knowledge regarding the toxicity effect of the substance.
- Short description of test condition: a dermal administration of the substance were performed to male and female rats for 2-years.
- Parameters analysed / observed: neoplastic e non-neoplastic effects were analysed; non-neoplastic effect were observed.

GLP compliance:

yes

Remarks:

These studies were conducted in compliance with FDA Good Laboratory Practice for nonclinical laboratory studies (21 CFR 58).

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material:
Pyrogallol was obtained from Aceto Corporation (Lake Success, NY; lot number 010326).
- Expiration date of the lot/batch:
not specified
- Purity test date:
Purity was determined by high-performance liquid chromatography with ultraviolet detection to be greater than 99%.

RADIOLABELLING INFORMATION (if applicable)
- Radiochemical purity:
not applicable
- Specific activity:
not applicable
- Locations of the label:
not applicable
- Expiration date of radiochemical substance:
not applicable

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material:
not specified
- Stability under test conditions:
not specified
- Solubility and stability of the test substance in the solvent/vehicle:
not specified
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium:
not specified

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing:
not specified
- Preliminary purification step (if any):
not specified
- Final dilution of a dissolved solid, stock liquid or gel:
not specified
- Final preparation of a solid:
not specified

FORM AS APPLIED IN THE TEST (if different from that of starting material)

TYPE OF BIOCIDE/PESTICIDE FORMULATION (if applicable)
: not applicable

OTHER SPECIFICS: Dose formulations were prepared by mixing pyrogallol and95% ethanol to give the required concentrations. Dose formulations were analyzed three times during the subchronic study and every three months during the chronic study and were within 10% of target pyrogallol concentrations.

Species:

rat

Strain:

Fischer 344

Details on species / strain selection:

not specified

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source:
obtained from Taconic Farms, Inc. (Germantown, NY)
- Females (if applicable) nulliparous and non-pregnant: [yes/no]
not specified
- Age at study initiation:
rats were 6–8 weeks old
- Weight at study initiation:
not specified
- Fasting period before study:
not specified
- Housing:
housed individually
- Diet (e.g. ad libitum):
Irradiated NTP-2000 wafer feed (Zeigler Brothers, Inc., Gardners, PA) was available ad libitum.
- Water (e.g. ad libitum):
tap water (Columbus, OH, municipal supply) was available ad libitum.
- Acclimation period:
quarantined for 14 days

DETAILS OF FOOD AND WATER QUALITY:
see above

ENVIRONMENTAL CONDITIONS
- Temperature (°C):
not specified
- Humidity (%):
not specified
- Air changes (per hr):
not specified
- Photoperiod (hrs dark / hrs light):
not specified

IN-LIFE DATES: From: To: not specified

Animal care and use were in accordance with the Laboratory Animal Welfare Act of 1966 (P.L. 89–544) as amended and the Public Health Service Policy on Humane Care and Use of Animals. Animals were treated humanely and with regard for alleviation of pain and distress. All animals were housed in facilities accredited by the Association for Assessment and Accreditation of Laboratory Animal Care and all procedures were approved by Battelle's Institutional Animal Care and Use Committee.

Route of administration:

dermal

Vehicle:

ethanol

Details on exposure:

TEST SITE
- Area of exposure: Pyrogallol was administered over the application site with a Corning Lambda (Corning, Inc., Corning, NY) single channel pipetter with a disposable polyethylene tip
- % coverage: not specified
- Type of wrap if used: -
- Time intervals for shavings or clipplings: An area slightly larger than the interscapular application site was clipped 24 hours before the first dose and weekly thereafter.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): not specified
- Time after start of exposure: not specified

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): Dosing volumes were 2.0 mL/kg body weight
- Concentration (if solution):
- Constant volume or concentration used: yes
- For solids, paste formed: not applicable

VEHICLE
- Justification for use and choice of vehicle (if other than water):
- Amount(s) applied (volume or weight with unit):
- Concentration (if solution):
- Lot/batch no. (if required):
- Purity:

USE OF RESTRAINERS FOR PREVENTING INGESTION: not specified

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

104 weeks

Frequency of treatment:

5 days per week

Post exposure period:

Body weights were recorded weekly for 13 weeks and monthly thereafter.

Dose / conc.:

0 other: mg/kg

Dose / conc.:

5 other: mg/kg

Remarks:

pyrogallol in 95% ethanol

Dose / conc.:

20 other: mg/kg

Remarks:

pyrogallol in 95% ethanol

Dose / conc.:

75 other: mg/kg

Remarks:

pyrogallol in 95% ethanol

No. of animals per sex per dose:

Groups of 50 male and 50 female

Control animals:

yes, concurrent vehicle

Details on study design:

- Toxicokinetic data
: not specified
- Dose selection rationale:
Dose was limited by the maximum solubility of pyrogallol in the 95% ethanol vehicle (300 mg/mL) and the fixed dosing volumes used (0.5 mL/kg rats, 2 mL/kg mice).
- Rationale for animal assignment (if not random): not specified
- Rationale for selecting satellite groups: not specified
- Post-exposure recovery period in satellite groups: not specified
- Section schedule rationale (if not random): not specified

Positive control:

no

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: no
- Time schedule: not applicable
- Cage side observations checked in table [No.?] were included. not applicable

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: clinical signs were recorded weekly

DERMAL IRRITATION (if dermal study): no
- Time schedule for examinations: not applicable

BODY WEIGHT: Yes
- Time schedule for examinations: recorded weekly.

FOOD CONSUMPTION: no
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: not applicable

FOOD EFFICIENCY: no
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: not applicable

WATER CONSUMPTION: no
- Time schedule for examinations: not applicable

OPHTHALMOSCOPIC EXAMINATION: no
- Time schedule for examinations: not applicable
- Dose groups that were examined: not applicable

HAEMATOLOGY: no
- Time schedule for collection of blood: not applicable
- Anaesthetic used for blood collection: not applicable
- Animals fasted: not applicable
- How many animals: not applicable
- Parameters checked in table [No.?] were examined. not applicable

CLINICAL CHEMISTRY: no
- Time schedule for collection of blood: not applicable
- Animals fasted: not applicable
- How many animals: not applicable
- Parameters checked in table [No.?] were examined. not applicable

URINALYSIS: no
- Time schedule for collection of urine: not applicable
- Metabolism cages used for collection of urine: not applicable
- Animals fasted: not applicable
- Parameters checked in table [No.?] were examined. not applicable

NEUROBEHAVIOURAL EXAMINATION: No
- Time schedule for examinations: not applicable
- Dose groups that were examined: not applicable
- Battery of functions tested: sensory activity / grip strength / motor activity / other: not applicable

OTHER: Weights of major organs were recorded at necropsy, including heart, liver, kidney, lung, testis, uterus, thymus and thyroid gland.

Animals were observed twice daily and clinical findings were recorded monthly beginning at week 5.n kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: Yes / No / No data

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Yes / No / No data
- Time schedule for examinations:

OPHTHALMOSCOPIC EXAMINATION: Yes / No / No data
- Time schedule for examinations:
- Dose groups that were examined:

HAEMATOLOGY: Yes / No / No data
- Time schedule for collection of blood:
- Anaesthetic used for blood collection: Yes (identity) / No / No data
- Animals fasted: Yes / No / No data
- How many animals:
- Parameters checked in table [No.?] were examined.

CLINICAL CHEMISTRY: Yes / No / No data
- Time schedule for collection of blood:
- Animals fasted: Yes / No / No data
- How many animals:
- Parameters checked in table [No.?] were examined.

URINALYSIS: Yes / No / No data
- Time schedule for collection of urine:
- Metabolism cages used for collection of urine: Yes / No / No data
- Animals fasted: Yes / No / No data
- Parameters checked in table [No.?] were examined.

NEUROBEHAVIOURAL EXAMINATION: Yes / No / No data
- Time schedule for examinations:
- Dose groups that were examined:
- Battery of functions tested: sensory activity / grip strength / motor activity / other:

OTHER:

Sacrifice and pathology:

not specified

Other examinations:

no other examinations were performed

Statistics:

To determine statistical differences between incidences, Fisher exact test and poly-3 test were used where applicable. Organ and body weight data were analyzed with the parametric multiple comparison procedures of Dunnett and Williams. Analysis of effects on survival used Cox's [25] method for testing two groups for equality and Tarone's life table test to identify dose-related trends

Clinical signs:

not examined

Mortality:

mortality observed, non-treatment-related

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not examined

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

The incidences of hyperplasia and hyperkeratosis were significantly greater than those in the vehicle control groups in most dosed groups of rats. Incidences of inflammation were significantly increased in several groups treated with 20 or 75 mg/kg. In addition, sebaceous gland hyperplasia was significantly increased.
Rats had only minimal (3–4 cell layers) to mild (5–6 cell layers) hyperplasia.
Hyperplasia was usually accompanied by varying degrees of hyperkeratosis, which was characterized by increased layers of keratin overlying the
epidermis. Hyperkeratosis was considered minimal if the keratin overlying the stratum granulosum was thin and loosely packed and mild when there was a
thick, dense, compact band of keratin above the stratum granulosum. Minimal to mild inflammation in the rat was characterized by scattered infiltrates of lymphocytes, macrophages, plasma cells, and neutrophils in the superficial dermis. In addition to the features seen in rats, mice also displayed marked inflammation with low numbers of mast cells in the dermis and occasional infiltration into the subcutis or epidermis.
Sebaceous gland hyperplasia was of minimal to mild severity in both rats and mice, and was characterized by increased incidences with increased doses and increased size of the sebaceous glands.

Histopathological findings: neoplastic:

no effects observed

Other effects:

not examined

Details on results:

Refer above.

Relevance of carcinogenic effects / potential:

not applicable.

Key result

Dose descriptor:

dose level:

Effect level:

5 other: mg/kg

Based on:

test mat.

Sex:

male/female

Basis for effect level:

histopathology: non-neoplastic

Critical effects observed:

yes

Lowest effective dose / conc.:

5 other: mg/kg

Organ:

skin

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

not specified

Conclusions:

There were dose-related, significantly increased incidences of squamous epithelial hyperplasia at the site of application in all dose groups of male and female rats. Squamous epithelial hyperplasia is considered a pre-neoplastic lesion in rats. However, relatively few squamous epithelial neoplastic lesions were observed in the skin.
In conclusion, dermal administration of pyrogallol caused high incidences of non-neoplastic lesions of the skin at the SOA in male and female rats, suggesting no carcinogenic potential but a local affect by dermal route.

Executive summary:

Pyrogallol (CAS No. 87-66-1), a benzenetriol used historically as a hair dye and currently in a number of industrial applications, was nominated to the National Toxicology Program (NTP) for testing based on lack of toxicity and carcinogenicity data. Three-month and two-year toxicity studies to determine the toxicity and carcinogenicity of pyrogallol when applied to naïve skin (i.e. dermal administration) were conducted in both sexes of F344/N rats and B6C3F1/N mice. In the three-month studies, adult rodents were administered pyrogallol in 95% ethanol 5 days per week for 3 months at doses of up to 150 mg /kg body weight (rats) or 600 mg/kg (mice). Based on the subchronic studies, the doses for the 2-year studies in rats and mice were 5, 20 and 75 mg/kg of pyrogallol. All mice and most rats survived until the end of the three-month study and body weights were comparable to controls. During the 2-year study, survival of dosed rats and male mice was comparable to controls; however survival of 75 mg/kg female mice was significantly decreased compared to controls. The incidences of microscopic non-neoplastic lesions at the site of application were significantly higher in all dosed groups of rats and mice and in both the 3 months and 2-year studies. In the 2-year study, hyperplasia, hyperkeratosis and inflammation tended to be more severe in mice than in rats, and in the mice they tended to be more severe in females than in males. The incidence of squamous cell carcinoma at the site of application (SOA) in 75 mg/kg female mice and SOA squamous cell papillomas in 75 mg/kg male mice were greater than controls. Pyrogallol was carcinogenic in female mice and may have caused tumors in male mice.

Reference 5

Endpoint:

carcinogenicity: dermal

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline available

Principles of method if other than guideline:

- Principle of test: Skin cancers are one of the largest groups of environmentally induced tumors; both radiation (sunlight) and certain chemicals are responsible and because is known about the toxicity and possible carcinogenicity of some chemicals (such as Pyrogallol) a carcinogenity study was performed.
- Short description of test conditions: Pyrogallol was applied to mouse skin
- Parameters analysed / observed: local changes, systemic response and tumor occurrence were noted

GLP compliance:

not specified

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Obtained from Nutritional Biochemical Company, Cleveland, Ohio.
- Expiration date of the lot/batch: not specified
- Purity test date: not specified

RADIOLABELLING INFORMATION (if applicable) not applicable
- Radiochemical purity:
- Specific activity:
- Locations of the label:
- Expiration date of radiochemical substance:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: not specified
- Stability under test conditions: not specified
- Solubility and stability of the test substance in the solvent/vehicle: not specified
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: not specified

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: not specified
- Preliminary purification step (if any): not specified
- Final dilution of a dissolved solid, stock liquid or gel: not specified
- Final preparation of a solid: not specified

FORM AS APPLIED IN THE TEST (if different from that of starting material) not applicable

TYPE OF BIOCIDE/PESTICIDE FORMULATION (if applicable) not applicable

OTHER SPECIFICS: The chemical was used as obtained from the manufacturer.

Species:

mouse

Strain:

Swiss

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Eppley colony
- Females (if applicable) nulliparous and non-pregnant: [yes/no] not specified
- Age at study initiation: Seven-week-old
- Weight at study initiation: not specified
- Fasting period before study: not specified
- Housing: Animals were housed in plastic cages with commercial bedding, 10 per cage
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: The animals were randomized prior to the start of the experiments, and the littermates were separated.

DETAILS OF FOOD AND WATER QUALITY: fed a commercial diet

ENVIRONMENTAL CONDITIONS
- Temperature (°C): not specified
- Humidity (%): not specified
- Air changes (per hr): not specified
- Photoperiod (hrs dark / hrs light): not specified

IN-LIFE DATES: From: To: not specified

Route of administration:

dermal

Details on exposure:

The chemicals (0.02 ml) were dropped on the dorsal skin between the flanks twice a week on a 1-inch square area which was shaved regularly. The animals were checked weekly, and all lesions, as well as tumors, were recorded. Animals were allowed to die spontaneously or were killed when moribund. Complete autopsies were performed on all animals. The skin from all animals, all grossly observed tumors and other lesions in the lungs, livers, kidneys, etc., from treated as well as control groups were studied histologically. Formalin-fixed paraffin-embedded specimens were cut
and stained with hematoxylin-eosin and other stains when needed

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

120 weeks

Frequency of treatment:

twice a week

Post exposure period:

no data

Dose / conc.:

5 other: %

Remarks:

in acetone

Dose / conc.:

25 other: %

Remarks:

in acetone

Dose / conc.:

50 other: %

Remarks:

in acetone

No. of animals per sex per dose:

There were 50 animals per concentration group.

Control animals:

yes

Positive control:

50 animals treated with 7,12-dimethylbenzanthracene as a positive control.

Observations and examinations performed and frequency:

Animals treated with pyrogallol showed no significant changes in the skin. Hyperplasia, ulceration or inflammation did not occur. The number of tumors produced was not significantly different from that in untreated controls. Skin tumors were not found. The number and distribution of the tumors were similar to that in other groups. Lymphomas, lung adenomas and liver hemangiomas were the most common tumors. The survival rate was slightly lower than in the untreated control group, but comparable to other groups

Statistics:

The statistical significance of the results was evaluated using the methods presented by Armitage

Clinical signs:

effects observed, non-treatment-related

Dermal irritation (if dermal study):

no effects observed

Mortality:

mortality observed, non-treatment-related

Body weight and weight changes:

not examined

Food efficiency:

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Description (incidence and severity):

The chemicals administered did not produce lesions in other organs directly related to the treatment

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

effects observed, non-treatment-related

Other effects:

not examined

Details on results:

the chemical studied does not produced a statistically significant increase in skin tumor incidence, when compared to untreated controls, and to those seen after repeated applications of DMBA. The skin tumor incidence seen in the treated animals (2-4x) was similar to that of the acetone control and untreated control animals. However, in the test groups 72 % were outside the treated area, in the positive control only 8 %. Thus from
our results it cannot be concluded that any of the chemicals studied are carcinogenic for skin. Swiss mice are very sensitive to skin tumors as seen in the positive control group, which shows a 78 % skin tumor incidence after painting with a known chemical carcinogen such as DMBA 10 microg twice weekly.

Relevance of carcinogenic effects / potential:

a significant percentage of the tumors were on the tail, ear, eyelid, lip and abdomen, which did not have direct contact with the chemicals, this speaks against a causal relationship between tumor incidence and treatment. The possibility exists that the mice rub against each other, which might spread the chemical.

NUMBER OF DIFFERENT TYPES OF HISTOLOGICALLY VERIFIED TUMORS IN SWISS MICE TREATED WITH DIFFERENT CHEMICALS

%(concentration) in acetone	Total N. of tumor bearing animals	Total N. of tumors	Lymphomas	Lung adenomas	Liver henangiomas	Thymomas	Skin tumors	other	% of tumor bearing animal
5	22	28	11	8	3	-	-	6a	44
25	18	23	12	6	3	-	-	2b	36
50	25	30	20	4	1	-	-	5c	50
untreated control	94	72	26	17	4	6	3	16w	42

a 2 mammary fibroadenomas, 2 mammary adenocarcinomas, 1 subcutaneous hemangioma, 1 ovarian fibroma.

b 2 mammary adenocarcinomas.

c 1 ovarian hemangioma, 1 ovarian cystadenoma, 1 lung adenocarcinoma, 1 hemangioma of the ear, 1 mammary fibroadenoma.

w 1 mammary fibroadenoma, 2 mammary adenocarcinomas, 1 subcutaneous fibroma, 3 subcutaneous fibrosarcomas, 1 subcutaneous hemangioma, 1 g

retroperitoneal fibromyxoma, 2 renal adenomas, 2 ovarian hemangiomas, 2 ovarian fibromas, 2 forestomach papillomas.

Conclusions:

The carcinogenicity of Pyrogallol was evaluated using 150 female Swiss mice (7 weeks old). Three groups of mice (50igroup) were treated with 5%, 25%, and 50% solutions of Pyrogallol (in acetone), respectively. Each solution (0.02 ml) was applied to dorsal shaved skin, between the flanks, twice per week. A total of 135 mice served as the untreated control group. Mice treated with acetone and 7,12-dimethylbenzanthracene served as vehicle and positive controls, respectivelyGross and microscopic examinations were performed. In all treatment groups, the number of neoplasms induced was not significantly different from that of the untreated control group. Lymphomas, pulmonary adenomas, and hepatic hemangiomas predominated. There were no skin neoplasms. At week 100, 13 of the 150 mice of the Pyrogallol groups were alive. None of the mice were alive at week 110. Survivors were noted in the control group during the 120th week.

Executive summary:

The potential carcinogenicity and toxicity pyrogallol were studied in female Swiss mice by administering repeated applications of the chemicals on the skin for the life-span of the animals. Tumors seen in both control and treated animals were mainly lymphomas, hemangiomas of the liver and lung adenomas,as well as tumors of other organs.A statistically significant increase in tumor incidence caused by the chemical treatment was not seen. Skin lesions, light inflammation and ulceration were seen, but no persistent cutaneous abnormalities occurred. A few skin tumors were seen in treated areas as well as in untreated areas and in control animals. Thus a carcinogenic or toxic potential which would affect the use of this agent in man was not detected.

Reference 6

Endpoint:

carcinogenicity: dermal

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline available

Principles of method if other than guideline:

- Principle of test: long-term studies in rabbits using epicutaneous application of several chemicals (as Pyrogallol used as cosmetic ingredient)
- Short description of test conditions: Pyrogallol was applied to rabbit skin
- Parameters analysed / observed: The local and systemic effects and the incidence and location of tumours are reported.

GLP compliance:

not specified

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Nutritional Biochemical Corporation, Cleveland, Ohio.
- Expiration date of the lot/batch: not specified
- Purity test date: not specified

RADIOLABELLING INFORMATION (if applicable) not applicable
- Radiochemical purity:
- Specific activity:
- Locations of the label:
- Expiration date of radiochemical substance:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: not specified
- Stability under test conditions: not specified
- Solubility and stability of the test substance in the solvent/vehicle: not specified
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: not specified

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: not specified
- Preliminary purification step (if any): not specified
- Final dilution of a dissolved solid, stock liquid or gel: not specified
- Final preparation of a solid: not specified

FORM AS APPLIED IN THE TEST (if different from that of starting material) the chemical was used as available and dissolved in acetone or methanol

TYPE OF BIOCIDE/PESTICIDE FORMULATION (if applicable) not applicable

OTHER SPECIFICS:

Species:

rabbit

Strain:

other: New Zealand

Remarks:

not known the color

Details on species / strain selection:

no data

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Ancare Corp., Manhasset, N. J
- Females (if applicable) nulliparous and non-pregnant: [yes/no] not specified
- Age at study initiation: 8 weeks old at the start of the experiment
- Weight at study initiation: no data
- Fasting period before study: no data
- Housing: They were kept in concrete pens, 5 in each, on straw bedding (groups 1-35), or housed individually in steel cages (groups 36-42).
- Diet (e.g. ad libitum): ad libitum.
- Water (e.g. ad libitum): ad libitum.
- Acclimation period: no data

DETAILS OF FOOD AND WATER QUALITY: were given pelleted diet (Wayne, Allied Mills, Chicago, Ill.)

ENVIRONMENTAL CONDITIONS
- Temperature (°C): no data
- Humidity (%): no data
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): no data

IN-LIFE DATES: From: To: no data

Route of administration:

dermal

Details on exposure:

0.02 ml of Pyrogallol was applied to the interior left ear.

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

160 weeks

Frequency of treatment:

twice a week

Post exposure period:

no data

Dose / conc.:

5 other: %

Dose / conc.:

25 other: %

Dose / conc.:

50 other: %

No. of animals per sex per dose:

5

Control animals:

yes

Positive control:

Positive controls (15 rabbits) were treated with 9,10-dimethylbenz[a]anthracene.

Observations and examinations performed and frequency:

The animals were checked weekly, and all lesions and tumours recorded. Complete autopsies were performed on all animals. Skin samples, grossly observed turnours and other lesions of the lungs, livers, kidneys, etc., from all the animals were studied histologically.
Formalin-fixed, paraffin-embedded specimens were cut and stained with hematoxylin-win and other stains as needed.

Statistics:

The statistical significance of the results was evaluated using the methods of ARMITAGE

Mortality:

no mortality observed

Histopathological findings: neoplastic:

effects observed, non-treatment-related

Conclusions:

The carcinogenicity of Pyrogallol in New Zealand rabbits (8 weeks old) was evaluated. Three groups of 5 rabbits were treated with solutions of 5%, 25%, and 50% Pyrogallol (in acetone or methanol), respectively. Fourteen rabbits served as untreated controls. Positive controls (15 rabbits) were treated with 9,10-dimethylbenz[a]anthracene. After 160 weeks of treatment, the only evidence of tumor formation in experimental groups was a uterine tumor in 1 animal treated with 50% Pyrogallol. A significant number of skin neoplasms (papillomas, squamous cell carcinomas, and keratocanthomas) was observed in the positive control group. Pyrogallol was not carcinogenic at any of the concentrations tested.

Executive summary:

A number of commonly used external agents were applied repeatedly on the skin of the mouse and rabbit. These chemicals, components of commercially (as pyrogallol) Also tested were a commercial hairspray, a dandruff shampoo and an anti-dandruff agent. Local and systemic changes were studied and the tumour incidence compared with that of an effective carcinogen, 9,10-dimethylbenz(a)anthracene. The mice showed no local toxic changes or tumour formation and the systemic tumour incidence, i. e., tumours of the liver, lungs, lymphatic system and other organs, was similar to that of control animals. In rabbits, a number of proliferative, benign and malignant ear tumours were observed in the positive controls, thereby demonstrating the efficiency of this model. Local toxic changes were seen in benzalkonium-and hexachlorophene-treated animals, but no skin tumours. Four animals had uterine tumours. In addition, one lung and one kidney tumour, unrelated to the method of treatment, were seen.

Reference 7

Endpoint:

carcinogenicity, other

Remarks:

subcutaneous

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

abstract

Qualifier:

no guideline available

Principles of method if other than guideline:

- Principle of test:
- Short description of test conditions:
- Parameters analysed / observed:

GLP compliance:

not specified

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material:
- Expiration date of the lot/batch:
- Purity test date:

RADIOLABELLING INFORMATION (if applicable)
- Radiochemical purity:
- Specific activity:
- Locations of the label:
- Expiration date of radiochemical substance:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material:
- Stability under test conditions:
- Solubility and stability of the test substance in the solvent/vehicle:
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium:

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing:
- Preliminary purification step (if any):
- Final dilution of a dissolved solid, stock liquid or gel:
- Final preparation of a solid:

FORM AS APPLIED IN THE TEST (if different from that of starting material)

TYPE OF BIOCIDE/PESTICIDE FORMULATION (if applicable)

OTHER SPECIFICS:

Species:

rat

Strain:

other: Fischer

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: not specified
- Females (if applicable) nulliparous and non-pregnant: [yes/no] not specified
- Age at study initiation: 2-week-old
- Weight at study initiation: not specified
- Fasting period before study: not specified
- Housing: not specified
- Diet (e.g. ad libitum): not specified
- Water (e.g. ad libitum): not specified
- Acclimation period: not specified

DETAILS OF FOOD AND WATER QUALITY: not specified

ENVIRONMENTAL CONDITIONS
- Temperature (°C): not specified
- Humidity (%): not specified
- Air changes (per hr): not specified
- Photoperiod (hrs dark / hrs light): not specified

IN-LIFE DATES: From: To: not specified

Route of administration:

subcutaneous

Vehicle:

DMSO

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

8 weeks (first dose) + 50 weeks (second dose)

Dose / conc.:

0.1 other: mg/g body weight

Dose / conc.:

14 other: mg/rat

No. of animals per sex per dose:

9 male and 10 female were treated.

Control animals:

yes

Details on study design:

no data

Positive control:

no data

Histopathological findings: neoplastic:

effects observed, treatment-related

In the experimental group, histiocytomas were observed at the injection sites of 3 male rats and 1 female rat. Neoplasms were not observed in controls

Conclusions:

Pyrogallol (in 50% DMSO) was administered subcutaneously (0.1 mg/g body weight) to 9 male and 10 female 2-week-old, Fischer rats for 8 weeks. During the next 50 weeks of treatment, the dose was changed to 14 mg/rat. Rats in the control group were dosed with 50% DMSO. In the experimental group, histiocytomas were observed at the injection sites of 3 male rats and 1 female rat. Neoplasms were not observed in controls. Nevertheless, effects are considered to be local.

Executive summary:

Pyrogallol (in 50% DMSO) was administered subcutaneously (0.1 mg/g body weight) to 9 male and 10 female 2-week-old, Fischer rats for 8 weeks. During the next 50 weeks of treatment, the dose was changed to 14 mg/rat. Rats in the control group were dosed with 50% DMSO. In the experimental group, histiocytomas were observed at the injection sites of 3 male rats and 1 female rat. Neoplasms were not observed in controls. Nevertheless, effects are considered to be local.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Carcinogenicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Carcinogenicity: via dermal route

Link to relevant study records

Reference

Endpoint:

carcinogenicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

no guideline available

Principles of method if other than guideline:

- Principle of test: Pyrogallol (CAS No. 87-66-1), a benzenetriol used historically as a hair dye and currently in a number of industrial applications, was studied in a 2 year study in order to evaluate carcinogenicity effects when applied to naïve skin (i.e. dermal administration) to rats. In a previous 3-months-study, adult rodents were administered the substance in order to fill the lack of knowledge regarding the toxicity effect of the substance.
- Short description of test condition: a dermal administration of the substance were performed to male and female rats for 2-years.
- Parameters analysed / observed: neoplastic e non-neoplastic effects were analysed; non-neoplastic effect were observed.

GLP compliance:

yes

Remarks:

These studies were conducted in compliance with FDA Good Laboratory Practice for nonclinical laboratory studies (21 CFR 58).

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material:
Pyrogallol was obtained from Aceto Corporation (Lake Success, NY; lot number 010326).
- Expiration date of the lot/batch:
not specified
- Purity test date:
Purity was determined by high-performance liquid chromatography with ultraviolet detection to be greater than 99%.

RADIOLABELLING INFORMATION (if applicable)
- Radiochemical purity:
not applicable
- Specific activity:
not applicable
- Locations of the label:
not applicable
- Expiration date of radiochemical substance:
not applicable

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material:
not specified
- Stability under test conditions:
not specified
- Solubility and stability of the test substance in the solvent/vehicle:
not specified
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium:
not specified

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing:
not specified
- Preliminary purification step (if any):
not specified
- Final dilution of a dissolved solid, stock liquid or gel:
not specified
- Final preparation of a solid:
not specified

FORM AS APPLIED IN THE TEST (if different from that of starting material)

TYPE OF BIOCIDE/PESTICIDE FORMULATION (if applicable)
: not applicable

OTHER SPECIFICS: Dose formulations were prepared by mixing pyrogallol and95% ethanol to give the required concentrations. Dose formulations were analyzed three times during the subchronic study and every three months during the chronic study and were within 10% of target pyrogallol concentrations.

Species:

rat

Strain:

Fischer 344

Details on species / strain selection:

not specified

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source:
obtained from Taconic Farms, Inc. (Germantown, NY)
- Females (if applicable) nulliparous and non-pregnant: [yes/no]
not specified
- Age at study initiation:
rats were 6–8 weeks old
- Weight at study initiation:
not specified
- Fasting period before study:
not specified
- Housing:
housed individually
- Diet (e.g. ad libitum):
Irradiated NTP-2000 wafer feed (Zeigler Brothers, Inc., Gardners, PA) was available ad libitum.
- Water (e.g. ad libitum):
tap water (Columbus, OH, municipal supply) was available ad libitum.
- Acclimation period:
quarantined for 14 days

DETAILS OF FOOD AND WATER QUALITY:
see above

ENVIRONMENTAL CONDITIONS
- Temperature (°C):
not specified
- Humidity (%):
not specified
- Air changes (per hr):
not specified
- Photoperiod (hrs dark / hrs light):
not specified

IN-LIFE DATES: From: To: not specified

Animal care and use were in accordance with the Laboratory Animal Welfare Act of 1966 (P.L. 89–544) as amended and the Public Health Service Policy on Humane Care and Use of Animals. Animals were treated humanely and with regard for alleviation of pain and distress. All animals were housed in facilities accredited by the Association for Assessment and Accreditation of Laboratory Animal Care and all procedures were approved by Battelle's Institutional Animal Care and Use Committee.

Route of administration:

dermal

Vehicle:

ethanol

Details on exposure:

TEST SITE
- Area of exposure: Pyrogallol was administered over the application site with a Corning Lambda (Corning, Inc., Corning, NY) single channel pipetter with a disposable polyethylene tip
- % coverage: not specified
- Type of wrap if used: -
- Time intervals for shavings or clipplings: An area slightly larger than the interscapular application site was clipped 24 hours before the first dose and weekly thereafter.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): not specified
- Time after start of exposure: not specified

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): Dosing volumes were 2.0 mL/kg body weight
- Concentration (if solution):
- Constant volume or concentration used: yes
- For solids, paste formed: not applicable

VEHICLE
- Justification for use and choice of vehicle (if other than water):
- Amount(s) applied (volume or weight with unit):
- Concentration (if solution):
- Lot/batch no. (if required):
- Purity:

USE OF RESTRAINERS FOR PREVENTING INGESTION: not specified

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

104 weeks

Frequency of treatment:

5 days per week

Post exposure period:

Body weights were recorded weekly for 13 weeks and monthly thereafter.

Dose / conc.:

0 other: mg/kg

Dose / conc.:

5 other: mg/kg

Remarks:

pyrogallol in 95% ethanol

Dose / conc.:

20 other: mg/kg

Remarks:

pyrogallol in 95% ethanol

Dose / conc.:

75 other: mg/kg

Remarks:

pyrogallol in 95% ethanol

No. of animals per sex per dose:

Groups of 50 male and 50 female

Control animals:

yes, concurrent vehicle

Details on study design:

- Toxicokinetic data
: not specified
- Dose selection rationale:
Dose was limited by the maximum solubility of pyrogallol in the 95% ethanol vehicle (300 mg/mL) and the fixed dosing volumes used (0.5 mL/kg rats, 2 mL/kg mice).
- Rationale for animal assignment (if not random): not specified
- Rationale for selecting satellite groups: not specified
- Post-exposure recovery period in satellite groups: not specified
- Section schedule rationale (if not random): not specified

Positive control:

no

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: no
- Time schedule: not applicable
- Cage side observations checked in table [No.?] were included. not applicable

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: clinical signs were recorded weekly

DERMAL IRRITATION (if dermal study): no
- Time schedule for examinations: not applicable

BODY WEIGHT: Yes
- Time schedule for examinations: recorded weekly.

FOOD CONSUMPTION: no
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: not applicable

FOOD EFFICIENCY: no
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: not applicable

WATER CONSUMPTION: no
- Time schedule for examinations: not applicable

OPHTHALMOSCOPIC EXAMINATION: no
- Time schedule for examinations: not applicable
- Dose groups that were examined: not applicable

HAEMATOLOGY: no
- Time schedule for collection of blood: not applicable
- Anaesthetic used for blood collection: not applicable
- Animals fasted: not applicable
- How many animals: not applicable
- Parameters checked in table [No.?] were examined. not applicable

CLINICAL CHEMISTRY: no
- Time schedule for collection of blood: not applicable
- Animals fasted: not applicable
- How many animals: not applicable
- Parameters checked in table [No.?] were examined. not applicable

URINALYSIS: no
- Time schedule for collection of urine: not applicable
- Metabolism cages used for collection of urine: not applicable
- Animals fasted: not applicable
- Parameters checked in table [No.?] were examined. not applicable

NEUROBEHAVIOURAL EXAMINATION: No
- Time schedule for examinations: not applicable
- Dose groups that were examined: not applicable
- Battery of functions tested: sensory activity / grip strength / motor activity / other: not applicable

OTHER: Weights of major organs were recorded at necropsy, including heart, liver, kidney, lung, testis, uterus, thymus and thyroid gland.

Animals were observed twice daily and clinical findings were recorded monthly beginning at week 5.n kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: Yes / No / No data

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Yes / No / No data
- Time schedule for examinations:

OPHTHALMOSCOPIC EXAMINATION: Yes / No / No data
- Time schedule for examinations:
- Dose groups that were examined:

HAEMATOLOGY: Yes / No / No data
- Time schedule for collection of blood:
- Anaesthetic used for blood collection: Yes (identity) / No / No data
- Animals fasted: Yes / No / No data
- How many animals:
- Parameters checked in table [No.?] were examined.

CLINICAL CHEMISTRY: Yes / No / No data
- Time schedule for collection of blood:
- Animals fasted: Yes / No / No data
- How many animals:
- Parameters checked in table [No.?] were examined.

URINALYSIS: Yes / No / No data
- Time schedule for collection of urine:
- Metabolism cages used for collection of urine: Yes / No / No data
- Animals fasted: Yes / No / No data
- Parameters checked in table [No.?] were examined.

NEUROBEHAVIOURAL EXAMINATION: Yes / No / No data
- Time schedule for examinations:
- Dose groups that were examined:
- Battery of functions tested: sensory activity / grip strength / motor activity / other:

OTHER:

Sacrifice and pathology:

not specified

Other examinations:

no other examinations were performed

Statistics:

To determine statistical differences between incidences, Fisher exact test and poly-3 test were used where applicable. Organ and body weight data were analyzed with the parametric multiple comparison procedures of Dunnett and Williams. Analysis of effects on survival used Cox's [25] method for testing two groups for equality and Tarone's life table test to identify dose-related trends

Clinical signs:

not examined

Mortality:

mortality observed, non-treatment-related

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not examined

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

The incidences of hyperplasia and hyperkeratosis were significantly greater than those in the vehicle control groups in most dosed groups of rats. Incidences of inflammation were significantly increased in several groups treated with 20 or 75 mg/kg. In addition, sebaceous gland hyperplasia was significantly increased.
Rats had only minimal (3–4 cell layers) to mild (5–6 cell layers) hyperplasia.
Hyperplasia was usually accompanied by varying degrees of hyperkeratosis, which was characterized by increased layers of keratin overlying the
epidermis. Hyperkeratosis was considered minimal if the keratin overlying the stratum granulosum was thin and loosely packed and mild when there was a
thick, dense, compact band of keratin above the stratum granulosum. Minimal to mild inflammation in the rat was characterized by scattered infiltrates of lymphocytes, macrophages, plasma cells, and neutrophils in the superficial dermis. In addition to the features seen in rats, mice also displayed marked inflammation with low numbers of mast cells in the dermis and occasional infiltration into the subcutis or epidermis.
Sebaceous gland hyperplasia was of minimal to mild severity in both rats and mice, and was characterized by increased incidences with increased doses and increased size of the sebaceous glands.

Histopathological findings: neoplastic:

no effects observed

Other effects:

not examined

Details on results:

Refer above.

Relevance of carcinogenic effects / potential:

not applicable.

Key result

Dose descriptor:

dose level:

Effect level:

5 other: mg/kg

Based on:

test mat.

Sex:

male/female

Basis for effect level:

histopathology: non-neoplastic

Critical effects observed:

yes

Lowest effective dose / conc.:

5 other: mg/kg

Organ:

skin

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

not specified

Conclusions:

There were dose-related, significantly increased incidences of squamous epithelial hyperplasia at the site of application in all dose groups of male and female rats. Squamous epithelial hyperplasia is considered a pre-neoplastic lesion in rats. However, relatively few squamous epithelial neoplastic lesions were observed in the skin.
In conclusion, dermal administration of pyrogallol caused high incidences of non-neoplastic lesions of the skin at the SOA in male and female rats, suggesting no carcinogenic potential but a local affect by dermal route.

Executive summary:

Pyrogallol (CAS No. 87-66-1), a benzenetriol used historically as a hair dye and currently in a number of industrial applications, was nominated to the National Toxicology Program (NTP) for testing based on lack of toxicity and carcinogenicity data. Three-month and two-year toxicity studies to determine the toxicity and carcinogenicity of pyrogallol when applied to naïve skin (i.e. dermal administration) were conducted in both sexes of F344/N rats and B6C3F1/N mice. In the three-month studies, adult rodents were administered pyrogallol in 95% ethanol 5 days per week for 3 months at doses of up to 150 mg /kg body weight (rats) or 600 mg/kg (mice). Based on the subchronic studies, the doses for the 2-year studies in rats and mice were 5, 20 and 75 mg/kg of pyrogallol. All mice and most rats survived until the end of the three-month study and body weights were comparable to controls. During the 2-year study, survival of dosed rats and male mice was comparable to controls; however survival of 75 mg/kg female mice was significantly decreased compared to controls. The incidences of microscopic non-neoplastic lesions at the site of application were significantly higher in all dosed groups of rats and mice and in both the 3 months and 2-year studies. In the 2-year study, hyperplasia, hyperkeratosis and inflammation tended to be more severe in mice than in rats, and in the mice they tended to be more severe in females than in males. The incidence of squamous cell carcinoma at the site of application (SOA) in 75 mg/kg female mice and SOA squamous cell papillomas in 75 mg/kg male mice were greater than controls. Pyrogallol was carcinogenic in female mice and may have caused tumors in male mice.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LOAEL

5 mg/kg bw/day

Study duration:

chronic

Species:

rat

Justification for classification or non-classification

Pyrogallol doesn't meet the criteria in Regulation (EC) 1272/2008 for classification, as no mutagenic effect in vivo is demonstrated and the data which suggest a carcinogenic effect are limited. Moreover, the substance increases the incidence of lesions of uncertain neoplastic potential ( Squamous epithelial hyperplasia, accompaigned by hyperketarosis). Also, differnet results are found in different species.