Biphenyl-2-ol

Endpoint summary

Description of key information

Oral: chronic toxicity, rat (OECD 453): NOAEL=39 mg/kg bw/day, LOAEL=200 mg/kg bw/day
Inhalation: no data available
Dermal: subacute toxicity, rat (OECD 410): NOAEL (systemic)≥1000 mg/kg bw/day, local irritation

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 453 (Combined Chronic Toxicity / Carcinogenicity Studies)

Deviations:

yes

Remarks:

animals were > 6 weeks of age when dosing commenced and the lowest dose is < 10% of highest dose for females

Qualifier:

according to guideline

Guideline:

other: US-EPA FIFRA Guideline 83-5

Qualifier:

according to guideline

Guideline:

other: EPA OTS 798.3320 (Combined Chronic Toxicity/Oncogenicity Studies)

Qualifier:

according to guideline

Guideline:

other: MAFF Guideline 59 NohSan No. 4200 Combined Chronic Toxicity/Oncogenicity Studies

GLP compliance:

yes

Specific details on test material used for the study:

- Name of test material (as cited in study report): ortho-phenylphenol (OPP)
- Stability: proven by purity analysis
- Storage condition of test material: under freezer conditions (approximately -23°C)

Species:

rat

Strain:

other: CDF[F344]/BR

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: SASCO, Inc., MAdison, WI
- Age at study initiation: approximately 8 weeks
- Fasting period before study: no
- Housing: individually in suspended stainless stell wire-mesh cages; each cage containing a feeder, a pressure-activated water nipple, and deotised cage board in the bedding tray
- Diet: Purina Mills Rodent Lab Chow 5001-4 in "etts" form, ad libitum
- Water: tap water (municipal water supply of Kansas City, MO
- Acclimation period: at least 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-26
- Humidity (%): 40-70
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: feed

Vehicle:

other: Acetone/corn oil mixture

Details on oral exposure:

DIET PREPARATION
- Rate of preparation of diet (frequency): weekly

VEHICLE
- Justification for use and choice of vehicle (if other than water): solubility properties of the test item

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

9 Analysis of the test substance in various test diets during the in-life phase of the study revealed mean analytical concentrations of 732 ppm (CV=6%), 3730 ppm (CV=8%), 7385 ppm (CV=8%), and 9510 ppm (CV=6%), with all values remaining within 10% of the corresponding nominam concentrations of 800, 4000, 8000, and 10,000 ppm, respectively.
The test substance was further shown to be stable following both room temperature and freezer storage over a period of 14 and 28 days and homogeneously distributed in the feed over a concentration range of 800-10,000 ppm.

Duration of treatment / exposure:

2 years

Frequency of treatment:

daily

Remarks:

Doses / Concentrations:
800, 4000, and 8000 (males) or 10,000 (females) ppm
Basis:
nominal in diet

Remarks:

Doses / Concentrations:
39±1, 200±3, and 402±6 mg/kg bw/day (males)
Basis:
other: mean daily intake calculated from feed consumption, body weight, and diet analysis data

Remarks:

Doses / Concentrations:
49±0, 248±3, and 647±6 mg/kg bw/day (females)
Basis:
other: mean daily intake calculated from feed consumption, body weight, and diet analysis data

No. of animals per sex per dose:

- control group: a total of 70 males + 70 females, 20 per sex served for interim sacrifice after 1 year, 50 per sex were kept and sacrificed after 2 years
- 800 ppm: a total of 60 males + 60 females, 10 per sex served for interim sacrifice after 1 year, 50 per sex were kept and sacrificed after 2 years
- 4000 ppm: a total of 60 males + 60 females, 10 per sex served for interim sacrifice after 1 year, 50 per sex were kept and sacrificed after 2 years
- 8000 ppm: a total of 70 males, 20 served for interim sacrifice after 1 year, 50 per sex were kept and sacrificed after 2 years
- 10,000 ppm: a total of 70 females, 20 served for interim sacrifice after 1 year, 50 per sex were kept and sacrificed after 2 years

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: based on literature review and a 4-week range finding study in the rat

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily (once on the weekends and holidays)
- Cage side observations included: moribundity and mortality, evaluation of external surface areas, orifices, posture, general behaviour, respiration, and excretory products

BODY WEIGHT: Yes
- Time schedule for examinations: weekly

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: pre-exposure and at sacrifice
- Dose groups that were examined: all animals

HAEMATOLOGY: Yes
- Time schedule for collection of blood: at 3, 6, 12, 18, and 24 months
- Anaesthetic used for blood collection: No data
- Animals fasted: Yes (overnight)
- How many animals: 20 rats/sex/dose (the same animals were used for urinalysis)
- Parameters checked: platelet count, leukocyte count, erythrocyte count, Hb, haematocrit, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), methaemoglobin (Met-Hb), leukocyte differential, (atypical lymphocytes, band neutrophils, basophils, blasts, hematrak comments, eosinophils, lymphocytes, metamyelocytes, monocytes, myelocytes, nucleated red blood cells (RBC), plasma cells, promyelocytes, segmented neutrophils), erythrocyte morphology (anisocytosis, basophilic stippling, hypersegmented neutrophils, hypochromasia, macrocytosis, microcytosis, poikilocytosis, polychromasia, spherocytosis, target cells, toxic granulation), special stains (reticulocyte count, heinz bodies)

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: at 3, 6, 12, 18, and 24 months
- Animals fasted: Yes (overnight)
- How many animals: 20 rats/sex/dose (the same animals were used for urinalysis)
- Parameters checked: Na, K, Cl, P, Ca, urea nitrogen, glucose, creatinine, uric acid, triglyceride, cholesterol, creatine kinase, lactate dehydrogenase (LDH), aspartate transaminase (AST), alanine transaminase (ALT), gamma-glutamyl transpeptidase (GGT), alkaline phosphatase (AP), total bilirubin, direct bilirubin, total protein, albumin, globulin

URINALYSIS: Yes
- Time schedule for collection of urine: at 3, 6, 12, 18, and 24 months (the week prior to the week of blood collection)
- Metabolism cages used for collection of urine: Yes
- Animals fasted: Yes (overnight)
- How many animals: 20 rats/sex/dose (the same animals were used for blood collection)
- Parameters checked: appearance, clarity, colour, specific gravity, pH, protein, glucose, ketones, bilirubin, blood, urobilinogen, nitrite, microscopic evaluation of solids

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
ORGAN WEIGHTS: Yes (adrenals, brain, heart, kidneys, liver, lungs, ovaries, spleen, testicles, thyroid)
HISTOPATHOLOGY: Yes (adrenals, aorta, bone (femur, Rib/cc jct, sternum), bone marrow, brain (cerebellum, cerebrum-midbrain, medulla/pons), caecum, cervix, clitoral gland, colon, epididymidis, oesophagus, exorbital(lacrimal gland, eyes, gross lesions, harderian gland, heart, joint fem/tib, kidneys, larynx, liver, lungs, lymph nodes (cervical and mesenteric), mammary gland, muscle, nerve (optic and sciatic), ovaries, pancreas, parathyroid, physical identifier, pituitary, prepupital gland, prostate, rectum, salivary gland, seminal vesicles, skin, skull, small intestine (duodenum, ileum, jejunum), spinal cord (cervical, lumbar, thoracic), spleen, stomach, testicles, thymus, thyroid, trachea, ureters, urinary bladder, uterus, vagina)

Statistics:

Continous data were evaluated initially for equality or homogeneity of variance using Bartlett's test. Group means were further analysed by a one-way variance analysis (ANOVA) followed by Dunnett's test. In the event of unequal variances, and at the discretion of the study director, data were subject to non-parametric procedures consisting of a Kruskal-Wallis ANOVA followed by the Mann-Whitney-U test for between-group comparisons. Frequency data were initially examined for trends, data suggestive of a potential effect were then statistically evaluated using the chi-square, Fisher-exact, or chi-square and Fisher-exact tests. On a case by case basis, and at the discretion of the study director, data were subject to additional statistical procedures other than mentioned above. For the Bartlett test, a probability (p) value of ≤0.01 was considered significant; for all other tests, differences with p values ≤0.05 were considered statistically significant.

Clinical signs:

no effects observed

Description (incidence and severity):

Changes noted are toxicologically not relevant.

Mortality:

no mortality observed

Description (incidence):

Changes noted are toxicologically not relevant.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

4000 ppm males/females: 5% decrased body weight gain; 8000 ppm males and 10,000 ppm females: 11% decrased body weight gain

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

no effects observed

Haematological findings:

no effects observed

Description (incidence and severity):

Changes noted are toxicologically not relevant.

Clinical biochemistry findings:

no effects observed

Description (incidence and severity):

Changes noted are toxicologically not relevant.

Urinalysis findings:

effects observed, treatment-related

Description (incidence and severity):

8000 ppm males: increased incidence of blood in urine

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

4000 ppm males: urinary bladder masses; 8000 ppm males: increased incidence of ventrum wet/stained and urinary bladder masses; 10,000 ppm females: increased incidence of ventrum wet/stained and pitted zones and abnormal texture in kidney

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

8000 ppm males: urinary bladder calculi, congestions, haemorrhage, mineralization, necrosis, calculi in renal pelvis, renal cystic tubular dilatation; 10,000 ppm females: renal mineralisation, renal cystic tubular dilatation, renal infarct

Histopathological findings: neoplastic:

effects observed, treatment-related

Description (incidence and severity):

8000 ppm males: simple urinary bladder hyperplasia, transitional cell carcinoma; 10,000 ppm females: simple urinary bladder hyperplasia, ureter dilatation and/or transitional cell hyperplasia, renal tubular hyperplasia

Details on results:

CLINICAL SIGNS AND MORTALITY
A slight increase in mortality was suggested for high dose males (8000 ppm), based on an increased number of unscheduled kills and a corresponding decrease in mean time of death (days). In contrast, a slight increase in mean time of death was observed for high dose females (10,000 ppm). Number of animals found dead on study was comparable between treated and control animals of each sex.
Test material related cage side observations were generally noted in mid and high dose animals (4000 and 8000/10,000 ppm) and included a statistically increased frequency of abnormal colour urination, urine stains, and red and/or brown stains primarily located in the perigenital area. While many interpretations regarding these observations may be plausible, the true toxicological significance, if any, remains unclear.

BODY WEIGHT AND WEIGHT GAIN
There was no test material-related effect noted in the low dose group (800 ppm) animals (both males and females). A decreased body weight of 5% was noted in both males and females treated with 4000 ppm and a decline of 11% was noted in high dose males (8000 ppm) and females (10,000 ppm).

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
There was no test material-related effect noted in any of the dose groups. Compound intake was calculated from feed consumption, body weight, and diet analysis data and amounted 39±1, 200±3, and 402±6 mg/kg bw/day for males and 49±0, 248±3, and 647±6 mg/kg bw/day for females, respectively.

OPHTHALMOSCOPIC EXAMINATION
There was no test material-related effect noted in any of the dose groups.

HAEMATOLOGY
There was no test material-related effect noted in low and mid dose animals (800 and 4000 ppm) and in high dose males (8000 ppm). Decreases in haemoglobin concentration, haematocrit, MCV and MCHC were suggested in high dose females (10,000 ppm); however, these changes were within the historical control range, did not persist over time intervals, and were therefore considered equivocal.

CLINICAL CHEMISTRY
There was no test material-related effect noted in any of the dose groups.

URINALYSIS
The only urinary consideration following exposure to OPP was increased incidence of blood in the urine of high dose males (8000 ppm). This finding is associated with the bladder neoplasia noted in high dose males.

ORGAN WEIGHTS
There was no test material-related effect noted in any of the dose groups.

GROSS PATHOLOGY
An increased incidence of urinary bladder masses was suggested for high dose males (8000 ppm) at both 1-year and 2-year sacrifices and for mid dose males (4000 ppm) at the 2-year sacrifice. This observation is likely associated with morphologic changes noted microscopically in the bladder.
An increase in the incidence of wet ventrum was noted in high dose females (10,000 ppm) at the interim sacrifice after 1 year of exposure. A similar increase in wet ventrum with staining was observed at terminal sacrifice in high dose males (8000 ppm) and females (10,000 ppm), and was simply a reiteration of the urine and the red staining of the perigenital area seen during the in-life portion of the study.
In the kidney, an increased incidence of pitted zones and abnormal texture was noted in highdose females (10,000 ppm) at terminal sacrifice.

HISTOPATHOLOGY: NON-NEOPLASTIC
Urinary bladder calculi, congestions, haemorrhage, mineralization and necrosis were noted in high dose males (8000 ppm) at terminal sacrifice after 2 years. At the interim sacrifice, high dose males showed further calculi in the renal pelvis and at terminal sacrifice renal cystic tubular dilatation was noted.
In high dose females (10,000 ppm), renal mineralisation were noted at terminal sacrifice after 2 years of exposure. Renal cystic tubular dilatation and renal infarct (wedge-shaped lesions without vascular involvement were noted in animals of the same group at both interim and terminal sacrifice.

HISTOPATHOLOGY: NEOPLASTIC (if applicable)
In high dose males (8000 ppm), simple urinary bladder hyperplasia and transitional cell carcinoma were noted at both 1- and 2-year sacrifices.
In high dose females (10,000 ppm), simple urinary bladder hyperplasia, ureter dilatation and/or transitional cell hyperplasia and renal tubular hyperplasia were noted at terminal sacrifice after 2 years of exposure.

Dose descriptor:

NOAEL

Remarks:

sytemic toxicity

Effect level:

39 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

other: corresponding to 800 ppm

Dose descriptor:

LOAEL

Remarks:

sytemic toxicity

Effect level:

200 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

other: corresponding to 4000 ppm; based on structural alterations in the urinary bladder

Dose descriptor:

NOAEL

Remarks:

sytemic toxicity

Effect level:

248 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: corresponding to 4000 ppm

Dose descriptor:

LOAEL

Remarks:

sytemic toxicity

Effect level:

647 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: corresponding to 10,000 ppm; based on renal mineralisation, renal cystic tubular dilatation, renal infarct

Critical effects observed:

not specified

The toxicological response to the 2 year daily intake of OPP can mainly characterized as structural alterations in the urinary bladder and kidney. But there was no compound-related change in various parameters associated with these organs at doses at 800 and 4000 ppm in both sexes. Body weight declined slightly at doses of 4000 ppm or above. Food consumption, ophthalmology, organ weights as well as haematological and clinical chemistry values remained unaffected. Urine analysis gave an increased incidence of blood in the urine of the 8000 ppm males only. Carcinogenicity: The urinary bladder showed evidence of a compound-induced neoplasia in both 4000- and 8000 ppm male rats only. While this effect was unequivocal at 8000 ppm, it was considered border-line at 4000 ppm as there was only a marginal and non-statistical increase in both urinary bladder hyperplasia and transitional cell carcinoma when compared to controls or 800 ppm males. Evidence of a compound-induced neoplasia was not observed in female animals at any dose tested.

NOAEL systemic, males: 800 ppm (39 mg/kg bw/day)

LOAEL systemic, males: 4000 ppm (200 mg/kg bw/day), based on structural alterations in the urinary bladder

NOAEL systemic, females: 4000 ppm (248 mg/kg bw/day)

LOAEL systemic, females: 10,000 ppm (647 mg/kg bw/day), based on renal mineralisation, renal cystic tubular dilatation, renal infarct

NOAEL carcinogenicity: 4000 ppm (200 mg/kg bw/day)

LOAEL carcinogenicity: 8000 ppm (402 mg/kg bw/day), based on neoplasms (malignant and benign) in the urinary bladder

NOAEL carcinogenicity, females: ≥10,000 ppm (647 mg/kg bw/day)

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

39 mg/kg bw/day

Study duration:

chronic

Species:

rat

Quality of whole database:

The available data comprises adequate and reliable (Klimisch score 1) studies. The selected study is thus sufficient to fulfil the standard information requirements set out in Annexes VIII-IX, 8.6 of Regulation (EC) No 1907/2006.

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 410 (Repeated Dose Dermal Toxicity: 21/28-Day Study)

Deviations:

yes

Remarks:

(adrenal weights not determined; clinical chemistry parameters suggested by OECD 410 but not evaluated: ornithine decarboxylase, gamma-glutamyl-transpeptidase)

Qualifier:

according to guideline

Guideline:

EU Method B.9 (Repeated Dose (28 Days) Toxicity (Dermal))

Deviations:

yes

Remarks:

(study duration should be 28 days, adrenal weights not determined)

Qualifier:

according to guideline

Guideline:

other: US-EPA FIFRA §82-2, November 1984

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Japanese MAFF, Subchronic Dermal Toxicity Study, 1985

Deviations:

no

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Kingston, Kingston, NY
- Age at study initiation: approximately 8 weeks
- Weight at study initiation: males: 167-196 g, females: 121-144 g
- Housing: individually in stainless steel cages
- Diet: Purina Certified Rodent Chow #5002 (Purina Mills Inc., St. Louis, MO) in meal form, ad libitum (except prior to necropsy)
- Water: municipal drinking water (City of Lake Jackson, TX), ad libitum
- Acclimation period: at least 7 days

ENVIRONMENTAL CONDITIONS- adequate (not further specified)
- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on exposure:

TEST SITE
- Area of exposure: back
- area covered: 5 cm²

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Application site was wiped with a water-dampened disposable gauze pad.

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

21 days

Frequency of treatment:

once daily on 5 days/week

Remarks:

Doses / Concentrations:
100, 500, and 1000 mg/kg bw/day
Basis:
nominal per unit body weight

No. of animals per sex per dose:

5

Control animals:

yes, sham-exposed

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: once daily
- Parameters checked: morbidity and mortality, presence of urine and faeces, alterations in skin, fur, mucous membranes, respiration, central nervous system function and animal behaviour

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: weekly

DERMAL IRRITATION (if dermal study): Yes
- Time schedule for examinations: daily after removal of test item

BODY WEIGHT: Yes
- Time schedule for examinations: pre-study and once weekly during the study period

FOOD CONSUMPTION:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes

FOOD EFFICIENCY:
- 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: Yes

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: pre-exposure and at necropsy
- Dose groups that were examined: all animals

HAEMATOLOGY: Yes
- Time schedule for collection of blood: prior to necropsy
- How many animals: all surviving animals
- Parameters checked: haematocrit, haemoglobin concentration, erythrocyte count, total and differential leukocyte count, platelet count, erythrocyte, leukocyte and platelet morphology

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: prior to necropsy
- How many animals: all surviving animals
- Parameters checked: sodium, potassium, chloride, calcium, phosphorus, fasting glucose, total bilirubin, blood urea nitrogen, creatinine, total protein, albumin, globulin, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase

URINALYSIS: Yes
- Time schedule for collection of urine: on Day 19
- Parameters checked: specific gravity, pH, protein, glucose, ketones, blood, bilirubin, urobilinogen, microscopic observation of solids

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
ORGAN WEIGHTS: Yes (liver, kidneys, testes, brain, heart)
HISTOPATHOLOGY: Yes (Control and high dose group; treated and untreated skin, liver, kidneys and gross lesions; mid dose group; untreated and treated skin. Tissues having grossly observable lesions and any target tissues identified in high dose group animals were also examined from animals of the intermediate dose groups.)

Statistics:

Descriptive statistics were calculated for feed consumption. Statistical outliers were identified by a sequential test.
Continuous data: Evaluation of variance was done with Bartlett’s test. If homogenous, group means were analysed by ANOVA followed by Dunnett’s test.

Clinical signs:

no effects observed

Dermal irritation:

effects observed, treatment-related

Description (incidence and severity):

dose-dependent local dermal irritation at 500 and 1000 mg/kg bw/day

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

no effects observed

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

not examined

Ophthalmological findings:

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

no effects observed

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

changes were noted in treated skin and were based on irritating properties of the test substance

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

changes were noted in treated skin and were based on irritating properties of the test substance

Histopathological findings: neoplastic:

not examined

Details on results:

CLINICAL SIGNS AND MORTALITY
No mortalities occurred throughout the study period.
Local irritation (erythema and scaling) of the application site was noted at 500 mg/kg bw/day and above. Oedema formation was not observed in either sex at any dose level. The authors suggest a dose-response relationship and a higher sensitivity of females to local dermal irritation as compared to males.

BODY WEIGHT AND WEIGHT GAIN
There was no test material-related adverse effect noted.

FOOD CONSUMPTION
There was no test material-related effect noted.

FOOD EFFICIENCY
There was no test material-related effect noted.

OPHTHALMOSCOPIC EXAMINATION
There was no test material-related effect noted.

HAEMATOLOGY
There was no test material-related effect noted.

CLINICAL CHEMISTRY
There was no adverse test material-related effect noted. Decresed aspartate aminotransferase activity in both sexes at 100 mg/kg bw/day and creatinin concentration in males treated with 500 mg/kg bw/day were considered to be not treatment-related.

URINALYSIS
There was no test material-related effect noted.

ORGAN WEIGHTS
There was no test material-related effect noted.

GROSS PATHOLOGY
Findings were limited to local skin irritation at the application site in mid- and high-dose animals (500 and 1000 mg/kg bw/day).

HISTOPATHOLOGY: NON-NEOPLASTIC
Hyperkeratosis and acanthosis were found in the treated skin of the mid- and high-dose animals (500 and 1000 mg/kg bw/day). The effects noted contribute to test substance-induced irritation rather than dermal toxicity. No other treatment-related findings were noted in liver or kidney in either male or female rats at any dose level.

Dose descriptor:

NOAEL

Remarks:

systemic

Effect level:

>= 1 000 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no adverse effects observed

Dose descriptor:

NOAEL

Remarks:

local

Effect level:

100 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

dermal irritation

histopathology: non-neoplastic

Critical effects observed:

not specified

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

The available data comprises adequate and reliable (Klimisch score 1) studies. The selected study is thus sufficient to fulfil the standard information requirements set out in Annexes VIII-IX, 8.6 of Regulation (EC) No 1907/2006.

Repeated dose toxicity: dermal - local effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 410 (Repeated Dose Dermal Toxicity: 21/28-Day Study)

Deviations:

yes

Remarks:

(adrenal weights not determined; clinical chemistry parameters suggested by OECD 410 but not evaluated: ornithine decarboxylase, gamma-glutamyl-transpeptidase)

Qualifier:

according to guideline

Guideline:

EU Method B.9 (Repeated Dose (28 Days) Toxicity (Dermal))

Deviations:

yes

Remarks:

(study duration should be 28 days, adrenal weights not determined)

Qualifier:

according to guideline

Guideline:

other: US-EPA FIFRA §82-2, November 1984

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Japanese MAFF, Subchronic Dermal Toxicity Study, 1985

Deviations:

no

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Kingston, Kingston, NY
- Age at study initiation: approximately 8 weeks
- Weight at study initiation: males: 167-196 g, females: 121-144 g
- Housing: individually in stainless steel cages
- Diet: Purina Certified Rodent Chow #5002 (Purina Mills Inc., St. Louis, MO) in meal form, ad libitum (except prior to necropsy)
- Water: municipal drinking water (City of Lake Jackson, TX), ad libitum
- Acclimation period: at least 7 days

ENVIRONMENTAL CONDITIONS- adequate (not further specified)
- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on exposure:

TEST SITE
- Area of exposure: back
- area covered: 5 cm²

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Application site was wiped with a water-dampened disposable gauze pad.

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

21 days

Frequency of treatment:

once daily on 5 days/week

Remarks:

Doses / Concentrations:
100, 500, and 1000 mg/kg bw/day
Basis:
nominal per unit body weight

No. of animals per sex per dose:

5

Control animals:

yes, sham-exposed

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: once daily
- Parameters checked: morbidity and mortality, presence of urine and faeces, alterations in skin, fur, mucous membranes, respiration, central nervous system function and animal behaviour

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: weekly

DERMAL IRRITATION (if dermal study): Yes
- Time schedule for examinations: daily after removal of test item

BODY WEIGHT: Yes
- Time schedule for examinations: pre-study and once weekly during the study period

FOOD CONSUMPTION:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes

FOOD EFFICIENCY:
- 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: Yes

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: pre-exposure and at necropsy
- Dose groups that were examined: all animals

HAEMATOLOGY: Yes
- Time schedule for collection of blood: prior to necropsy
- How many animals: all surviving animals
- Parameters checked: haematocrit, haemoglobin concentration, erythrocyte count, total and differential leukocyte count, platelet count, erythrocyte, leukocyte and platelet morphology

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: prior to necropsy
- How many animals: all surviving animals
- Parameters checked: sodium, potassium, chloride, calcium, phosphorus, fasting glucose, total bilirubin, blood urea nitrogen, creatinine, total protein, albumin, globulin, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase

URINALYSIS: Yes
- Time schedule for collection of urine: on Day 19
- Parameters checked: specific gravity, pH, protein, glucose, ketones, blood, bilirubin, urobilinogen, microscopic observation of solids

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
ORGAN WEIGHTS: Yes (liver, kidneys, testes, brain, heart)
HISTOPATHOLOGY: Yes (Control and high dose group; treated and untreated skin, liver, kidneys and gross lesions; mid dose group; untreated and treated skin. Tissues having grossly observable lesions and any target tissues identified in high dose group animals were also examined from animals of the intermediate dose groups.)

Statistics:

Descriptive statistics were calculated for feed consumption. Statistical outliers were identified by a sequential test.
Continuous data: Evaluation of variance was done with Bartlett’s test. If homogenous, group means were analysed by ANOVA followed by Dunnett’s test.

Clinical signs:

no effects observed

Dermal irritation:

effects observed, treatment-related

Description (incidence and severity):

dose-dependent local dermal irritation at 500 and 1000 mg/kg bw/day

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

no effects observed

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

not examined

Ophthalmological findings:

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

no effects observed

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

changes were noted in treated skin and were based on irritating properties of the test substance

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

changes were noted in treated skin and were based on irritating properties of the test substance

Histopathological findings: neoplastic:

not examined

Details on results:

CLINICAL SIGNS AND MORTALITY
No mortalities occurred throughout the study period.
Local irritation (erythema and scaling) of the application site was noted at 500 mg/kg bw/day and above. Oedema formation was not observed in either sex at any dose level. The authors suggest a dose-response relationship and a higher sensitivity of females to local dermal irritation as compared to males.

BODY WEIGHT AND WEIGHT GAIN
There was no test material-related adverse effect noted.

FOOD CONSUMPTION
There was no test material-related effect noted.

FOOD EFFICIENCY
There was no test material-related effect noted.

OPHTHALMOSCOPIC EXAMINATION
There was no test material-related effect noted.

HAEMATOLOGY
There was no test material-related effect noted.

CLINICAL CHEMISTRY
There was no adverse test material-related effect noted. Decresed aspartate aminotransferase activity in both sexes at 100 mg/kg bw/day and creatinin concentration in males treated with 500 mg/kg bw/day were considered to be not treatment-related.

URINALYSIS
There was no test material-related effect noted.

ORGAN WEIGHTS
There was no test material-related effect noted.

GROSS PATHOLOGY
Findings were limited to local skin irritation at the application site in mid- and high-dose animals (500 and 1000 mg/kg bw/day).

HISTOPATHOLOGY: NON-NEOPLASTIC
Hyperkeratosis and acanthosis were found in the treated skin of the mid- and high-dose animals (500 and 1000 mg/kg bw/day). The effects noted contribute to test substance-induced irritation rather than dermal toxicity. No other treatment-related findings were noted in liver or kidney in either male or female rats at any dose level.

Dose descriptor:

NOAEL

Remarks:

systemic

Effect level:

>= 1 000 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no adverse effects observed

Dose descriptor:

NOAEL

Remarks:

local

Effect level:

100 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

dermal irritation

histopathology: non-neoplastic

Critical effects observed:

not specified

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Study duration:

subacute

Species:

rat

Quality of whole database:

The available data comprises adequate and reliable (Klimisch score 1) studies.

Additional information

The long-term toxicity of 2-phenylphenol (OPP) was extensively studied in rats, mice and dogs:

In the combined chronic toxicity/carcinogenicity key study (Wahle, B.S. and Christenson, W.R., 1996; Wahle, B.S. and Christenson, W.R., 1999; Wahle, B.S. et al., 1997 and Bomhard, E. M. et al., 2002) Fischer rats received OPP in the diet. Systemic toxicity was noted as decreased body weight at mid and high doses for both sexes during all treatment periods. There was an increase in the urinary bladder hyperplasia at 12 and 24 month in high dose males (and high dose females at 24 months) along with an increase in congestion, haemorrhage, mineralisation and necrosis. Non-neoplastic findings consisted of increased incidence of calculi in the kidneys in high dose males and in the urinary bladder at 12 and 24 months, respectively. High dose males and females also had an increase in cysts of the kidneys at 24 months. High dose females had an increase in hyperplasia of the kidney along with increase infarct, acute inflammation and mineralisation of the kidney. In male rats there was an increased incidence of urinary bladder papillomas, transitional cell carcinomas, and/or combined papillomas and/or transitional cell carcinomas at 8000 ppm. The NOAEL for systemic long-term toxicity and for carcinogenicity was 800 ppm (39 mg/kg bw/day). The authors assumed that the mechanism of tumourigenesis in rats was non-genotoxic, probably based on chronic irritation of the epithelium by a combination of high pH, high sodium-ion concentration and/or high concentration of free metabolites at high doses.

In the second combined chronic toxicity/carcinogenicity study (according to OECD 453 and in compliance with GLP) male and female B6C3F1 mice were fed with OPP at dietary levels of 250, 500 or 1000 mg/kg bw. Systemic toxicity was noted as decreased body weight gain throughout the study and an increase in absolute and relative liver weights at 12 and 24 months in all treated males and females. Additionally, a dose-related increase of microvacuolation in the tubular epithelial cells of the kidney cortex together with an increased incidence and severity of degeneration and decreased regeneration of their tubules was noted at 12 and 24 months in males. Mice did not develop any treatment-related effects in the urinary bladder. An increased incidence of liver adenoma, carcinoma and hepatoblastoma was observed in male mice at 500 mg/kg bw/day and 1000 mg/kg bw/day. The NOAEL for systemic toxicity in mice was <250 mg/kg bw/day, whereas the NOAEL for tumours was 250 mg/kg bw/day (Quast, J.F. and McGuirk, R.J., 1995 and Bomhard, E. M. et al., 2002).

Latest investigations on a mode of action for the development of liver tumours in mice show that a receptor mediated mechanism via the peroxisome-proliferator-activated-receptor-alpha (PPARa) is probable for the liver enlargement. This mechanism is known to be of no direct concern for humans (Geter, D.R., 2009, Section 7.9.3).

In a 2-year dermal study in rats, OPP caused non-neoplastic lesions, which included ulceration, inflammation and hyperkeratosis at the site of application (Zempel, J. A. and Szabo, J. R., 1993 and Bomhard, E. M. et al., 2002).

In subchronic/chronic studies in dog (4-weeks gavage and 1-year gavage) the NOAEL was set at ≥300 mg/kg bw/day, based on increased emesis with respect to the controls at highest doses. The emesis observed at 300 mg/kg bw/day was categorized as a local transitory response of the upper alimentary duct and no adverse toxicological effects were observed in comprehensive examinations Cosse, P.F. et al., 1990 and Bomhard, E. M. et al., 2002).

There are various further repeated dose toxicity data summarised by Bomhard, E. M. et al. (2002). All these data are in line with the findings described above and support the conclusion presented below.

For the risk assessment of OPP the following values may be taken as key data for the characterization of long-term toxicity effects:

NOAEL (rat): 39 mg/kg/d (Wahle & Christensen, 1996)

NOAEL (dog): ≥300 mg/kg/d (Cosse et al., 1990)

NOAEL (mouse): 250 mg/kg/d (Quast & McGuirk, 1995)

This is in general agreement with the evaluations of FAO-WHO (1999), US-EPA (2006) and EU EFSA (2008) for deriving the ADI using the oral long term NOEL (rat) = 39 mg/kg/d as a starting point and using the conventional margin of safety approach.

Justification for selection of repeated dose toxicity via oral route - systemic effects endpoint:
The selected study is the most adequate and reliable one based on the overall assessment of quality, and with special respect to duration and effect level.

Justification for selection of repeated dose toxicity inhalation - systemic effects endpoint:
The registered substance is marketed or used as flakes (0.17% < 100 µm). Exposure to particles of inhalable size is thus unlikely. Therefore, inhalation is not the most relevant route of exposure. According to Annex VIII, 8.6.2 of Regulation (EC) No1907/2006, column 2, the testing of repeated dose toxicity via the inhalation route can be omitted as this is not the most relevant route of human exposure, and data from a chronic toxicity study via the oral route and from a subacute toxicity study via the dermal route are available.

Justification for selection of repeated dose toxicity inhalation - local effects endpoint:
The registered substance is marketed or used as flakes (0.17% < 100 µm). Exposure to particles of inhalable size is thus unlikely. Therefore, inhalation is not the most relevant route of exposure. According to Annex VIII, 8.6.2 of Regulation (EC) No1907/2006, column 2, the testing of repeated dose toxicity via the inhalation route can be omitted as this is not the most relevant route of human exposure, and data from a chronic toxicity study via the oral route and from a subacute toxicity study via the dermal route are available.

Justification for selection of repeated dose toxicity dermal - systemic effects endpoint:
The selected study is the most adequate and reliable one based on the overall assessment of quality (GLP guideline study, reliability 1), and with special respect to duration and data presentation.

Justification for selection of repeated dose toxicity dermal - local effects endpoint:
The selected study is the most adequate and reliable one based on the overall assessment of quality (GLP guideline study, reliability 1), and with special respect to duration and data presentation.

Repeated dose toxicity: via oral route - systemic effects (target organ) urogenital: urinary bladder

Justification for classification or non-classification

Repeated dose administration of 2-phenylphenol for 2 years in the diet revealed a NOAEL of 39 mg/kg bw/d, and repeated dermal administration for 21 days revealed a NOAEL for systemic toxicity of ≥1000 mg/kg bw/d.

Based on these data, the registered substance does not meet the criteria to be classified for Specific Target Organ Toxicity - Repeated Exposure according to the criteria of the EU Directive 67/548/EEC and Regulation (EC) No 1272/2008.