2-chloro-p-phenylenediamine

Endpoint summary

Description of key information

Under the condition of the study, the no-observed adverse effect level (NOAEL) of 2-chloro-p-phenylenediamine (o-chloro-p-PD) (CAS No. 615-66-7) in rats was considered to be 200 mg/kg/day.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Justification for type of information:

Data is from peer-reviewed journal

Qualifier:

no guideline available

Principles of method if other than guideline:

The subacute repeated dose toxicity study of 2-chloro-p-phenylenediamine (CAS No. 615-66-7) in rats was conducted to evaluate adverse effects by oral route.

GLP compliance:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): 2-chloro-p-phenylenediamine (o-chloro-p-PD)
- Molecular formula: C6H7N2Cl
- Molecular weight: 142.59 g/mole
- Substance type: Organic
- Physical state: Solid

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Wilmington,MA
- Age at study initiation: No data available
- Weight at study initiation: 225-250 g
- Fasting period before study: No data available
- Housing: Animals were housed separately
- Diet (e.g. ad libitum): Purina Laboratory Rodent Chow, ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 2 weeks

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

IN-LIFE DATES: From: To: No data available

Route of administration:

oral: gavage

Vehicle:

propylene glycol

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS: o-chloro-p-phenylenediamine was dissolved in propylene glycol before administration.

DIET PREPARATION
- Rate of preparation of diet (frequency): No data available
- Mixing appropriate amounts with (Type of food): No data available
- Storage temperature of food: No data available

VEHICLE
- Justification for use and choice of vehicle (if other than water): Propylene glycol
- Concentration in vehicle: 100, 200 and 400 mg/kg/day
- Amount of vehicle (if gavage): 10 ml/kg
- Lot/batch no. (if required): No data available
- Purity: No data available

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

10 days

Frequency of treatment:

Daily

Remarks:

Doses / Concentrations:
0, 100, 200 and 400 mg/kg/day

Basis:
nominal in diet

No. of animals per sex per dose:

Total : 53
10 ml/kg : 20 female
100 mg/kg/day : 11 female
200 mg/kg/day : 11 female
400 mg/kg/day : 11 female

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: The dose was determined from previously estimated maximum tolerated doses.
- Rationale for animal assignment (if not random): Pregnant females were assigned on a random basis to 100, 200 and 400 mg/kg/day
- Rationale for selecting satellite groups: No data available
- Post-exposure recovery period in satellite groups: No data available
- Section schedule rationale (if not random): No data available

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS:
- Time schedule: Daily
- Cage side observations checked in table [No.?] were included: Mortality was observed.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Daily general health and condition were observed.

BODY WEIGHT: Yes
- Time schedule for examinations: On days 0, 6, 16 and 20

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): No data available
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No data available
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No data available

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: No data available

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

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

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

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

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

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

Sacrifice and pathology:

GROSS PATHOLOGY:
Implantation sites, external fetal malformations, head, trunk and limbs were examined.

One half of the fetuses randomly selected from each litter were placed in Bouin's fixative for subsequent visceral examination according to Wilson's procedure (Wilson & Warkany, 1965). The remaining half of the fetuses were eviscerated, fixed in 95 % isopropyl alcohol, macerated in potassium hydroxide and stained with Alizarin Red S by a method similar to that of Dawson (1926), for subsequent skeletal evaluation.

HISTOPATHOLOGY: No data available

Other examinations:

Number of fetus, foetal malformations, and skeletal abnormalities of fetus were observed.

Statistics:

Weight changes, the number of fetal implantations, fetal weights and the fetal sex ratio were analyzed by using Student's t test, vehicle control data were combined after an analysis of variance.

Clinical signs:

no effects observed

Description (incidence and severity):

No abmormalities were observed in treated female rats.

Mortality:

no mortality observed

Description (incidence):

No mortality were observed in treated female rats.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Mean weight gain was decreased on 6-16 day in 200 mg/kg/day and on 6-20 day in 400 mg/kg/day treated female rats.

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

No gross pathological effect was observed in treated female rats as compared to control.

Neuropathological findings:

not specified

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Details on results:

Statistically significant increase in the number of resorptions was observed in 400 mg/kg/day treated female rats as compared to control.

Dose descriptor:

NOAEL

Effect level:

200 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

female

Basis for effect level:

body weight and weight gain

clinical signs

gross pathology

mortality

other: No adverse effect on survival, clinical sign, body weight, gross pathology and fetal development was observed.

Critical effects observed:

no

Conclusions:

Under the condition of the study, the no-observed adverse effect level (NOAEL) of 2-chloro-p-phenylenediamine (o-chloro-p-PD) (CAS No. 615-66-7) in rats was considered to be 200 mg/kg/day.

Executive summary:

The subacute repeated dose toxicity study of 2-chloro-p-phenylenediamine (CAS No. 615-66-7) in female Sprague-Dawley rats was conducted to evaluate the adverse effects by oral route. The test chemical was administered by oral gavage in the concentration of 100, 200 and 400 mg/kg/day. The results showed reduction in mean body weight gain of 200 and 400 mg/kg/day treated rats. No mortality were observed. Clinical signs was not observed. In addition, statistically significant increase in the number of resorptions was observed in 400 mg/kg/day treated female rats as compared to control.  No changes were observed in gross pathology of treated rats as compared to control. Thus, the no-observed adverse effect level (NOAEL) of 2-chloro-p-phenylenedi amine (o-chloro-p-PD) (CAS No. 615-66-7) in rats was considered to be 200 mg/kg/day.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

200 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

The data is Klimicsh 2 and from peer-reviewed journal

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

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Repeated dose toxicity: oral

Various repeated dose toxicity studies has been investigated to observe the adverse general toxicological effects occurring as a result of repeated daily dosing with, or exposure, to a substance for a specified period up to the expected lifespan of the test species. Often are the studies based on experimental data in rodents for 2-chloro-p-phenylenediamine(CAS No. 615-66-7) along with the study available on structurally similar read across substances 2-chloro-p-phenylenediamine sulfate (CAS No.61702-44-1) and 2, 4, 6-trichloroaniline (CAS No. 634-93-5). The studies are summarized as below:

 

The subacute repeated dose toxicity study of 2-chloro-p-phenylenediamine (CAS No. 615-66-7) in female Sprague-Dawley rats was conducted by J. C. Picciano et al., (Fd Chem. Toxic. Vol. 22, no. 2, pp. I47 149, 1984) to evaluate the adverse effects by oral route. The test chemical was administered by oral gavage in the concentration of 100, 200 and 400 mg/kg/day. The results showed reduction in mean body weight gain of 200 and 400 mg/kg/day treated rats. No mortality were observed. Clinical signs was not observed. In addition, statistically significant increase in the number of resorptions was observed in 400 mg/kg/day treated female rats as compared to control.  No changes were observed in gross pathology of treated rats as compared to control. Thus, the no-observed adverse effect level (NOAEL) of 2-chloro-p-phenylenedi amine (o-chloro-p-PD) (CAS No. 615-66-7) in rats was considered to be 200 mg/kg/day.

 

Also, the above study is supported by the Combined repeated dose & carcinogenicity study published by Elizabeth K.Weisburger et al., (Carcinogenesis, Volume 1, June 1980, page no. 495-499) on structurally similar read across substance 2-chloro-p-phenylenediamine sulfate (CAS No.- 61702-44-1); the test chemical was administered by oral feed in the concentration of 0, 0.15 and 0.3 %. The results showed no effect on survival. In addition, histopathological changes were observed as Hyperplasia of Transitional cell of Kidney/Pelvis and Neoplastic nodule in liver. Although the analog, 2-chloro-p-phenylene diamine increased transitional cell hyperplasia of the kidney in both male and female rats, it had no significant neoplastic effect at the 0.15 and 0.3% levels fed . Therefore, NOAEL was considered to be 0.3 % (150 mg/kg/day) when Fischer 344 rats exposed to test substance orally.

 

In a similar type of chronic repeated dose toxicity study by Elizabeth K.Weisburger et al., Carcinogenesis, Volume 1, June 1980, page no. 495-499), the effect of 2-chloro-p-phenylenediamine sulfate was evaluated in male and female B6C3F1mice. The test chemical was administered by oral feed in the concentration of 0, 0.3 and 0.6 %. The results showed no effect on survival. In addition, no gross pathlogical and histopathological changes were observed in treated mice. Hepatocellular adenoma and carcinoma of Liver were observed but the effect was not significant. Therefore, NOAEL was considered to be 0.6 % (1000 mg/kg/day) when B6C3F1mice exposed to test substance orally. 

 

Moreover, in a chronic repeated dose toxicity study by National Cancer Institute (Technical Report, Series No. 113, 1978, page no. 1-104.), the effect of 2-chloro-p -phenylenediamine sulfate was evaluated in male and female Fischer 344 rats. The test chemical was administered by oral feed in the concentration of 0, 0.15 and 0.30 %. The results showed Eye discoloration, swelling, reddening and crustation, subcutaneous masses, abdominal distention and reduction in survival when treated with 0.30 %. In addition, gross pathological and histopathological changes were also observed as Transitional-Cell Hyperplasia of the renal pelvis but however, the nature and incidences of these neoplasms are similar to those known to occur spontaneously in aged Fischer 344 rats. Therefore, NOAEL was considered to be 0.30 % (150 mg/kg/day) when Fischer 344 rats exposed to test substance orally. 

On the basis of evidence from above studies (target substance and to its read across substances) in experimental animals, it can be presumed that there is no potential to be harmful to human health following repeated exposure. The substance 2-chloro-p-phenylenediamine(CAS No. 615-66-7)is unclassified because no specific target organ toxicity was seen. Thus, on the basis of CLP classification criteria the substance is not classified.

Repeated dose toxicity: inhalation

According to Annex IX of the REACH regulation, testing by the inhalation route is appropriate only if exposure of humans via inhalation is likely. Taking into account the low vapour pressure of the substance 2-chloro-p-phenylenediamine, which is reported as  0.00206 mm Hg. Thus, exposure to inhalable dust, mist and vapour of the chemical 2-chloro-p-phenylenediamine  is highly unlikely. Therefore this study is considered for waiver.

Repeated dose toxicity: dermal 

The acute toxicity value for 2-chloro-p-phenylenediamine (as provided in section 7.2.3) is >2000 mg/kg body weight. The substance was also found to be not irrtating to skin.  Also, given the use of the chemical as a hair dyeing agents; repeated exposure by the dermal route is unlikely. Thus, it is expected that 2-chloro-p-phenylenediamine  shall not exhibit 28 day repeated dose toxicity by the dermal route. In addition, there is no dermal absorption data as well as no data available that suggests that 2-chloro-p-phenylenediamine shall exhibit repeated dose toxicity by the dermal route. Hence this end point was considered for waiver.

Justification for classification or non-classification

Based on the available data for the assessment of repeated dose toxicity by oral, inhalation and dermal route and following CLP Regulation (EC) No 1272/2008, the substance 2-chloro-p-phenylenediamine is not classified.