2-[(4-aminophenyl)azo]-1,3-dimethyl-1H-imidazolium chloride

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

28Sep2001 to 21Jan2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2001

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method)

GLP compliance:

yes

Test type:

fixed dose procedure

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2-[(4-aminophenyl)azo]-1,3-dimethyl-1H-imidazolium chloride

EC Number:

306-764-4

EC Name:

2-[(4-aminophenyl)azo]-1,3-dimethyl-1H-imidazolium chloride

Cas Number:

97404-02-9

Molecular formula:

C11H14N5.Cl

IUPAC Name:

2-[(1E)-2-(4-aminophenyl)diazen-1-yl]-1,3-dimethyl-2,3-dihydro-1H-imidazol-1-ium chloride

Test material form:

solid: particulate/powder

Details on test material:

See individual study reports for purity information and CofA where applicable

Specific details on test material used for the study:

Lot No. 013673A1
received from the Sponsor on September 17, 2001

Test animals

Species:

rat

Strain:

other: Crl:CD (SD) IGS BR

Sex:

male/female

Details on test animals or test system and environmental conditions:

Young, adult male and female Crl:CD (SD)IGS BR rats were received from Charles River Laboratories, a USDA-approved supplier located in Raleigh, North Carolina, on October 23 and 30,2001.
The animals were assigned temporary numbers during acclimation and identified by individual numbered ear tag and by cage label for the duration of the study.

Housing
The animals were pair housed during the acclimation period and singly housed during the study period in hanging, stainless-steel, wire-mesh cages measuring approximately
24.2 cm X 22.0 cm x 17.3 cm. ,

Diet
A commercial diet (PMf Feeds, Inc. Certified Rodent Diet'^ #5002 - pellet form) was available ad libitum during the acclimation and study periods, with the exception of a period for 17 to 20 hours prior to and approximately 4 hours after test material administration. The feed was analyzed by the manufacturer for concentrations of specified heavy metals, aflatoxin, chlorinated hydrocarbons, organophosphates, and specified nutrients. Results are on file at Covance-Vienna.

Water
Water, via an automatic watering system, was available ad libitum during the acclimation and study periods. The water was analyzed on a routine basis for specified microorganisms, pesticides, alkalinity, heavy metals, and halogens. Specified nutrient and contaminant analyses are on file at Covance - Vienna. There were no contaminants, known or reasonably anticipated, in the diet or water at levels that might interfere with the validity of this study.

Environment
The temperature and relative humidity in the animal room were monitored at least once daily.
Room controls were set to maintain temperatures and relative humidity of 18-26°C (64-79° F) and 50%±20%, respectively. A 12-hour light/12-hour dark cycle was maintained in the. Room housing the animals. Ten or greater air changes per hour were maintained in the room housing the animals.

Acclimation
Before being considered for study use, the animals were acclimated to laboratory conditions. After at least 5 days of acclimation, a staff veterinarian deemed them to be healthy and free from disease and physical abnormalities, and then released the animals for use in the study.

Selection of Animals
Animals used in this study were allocated from all animals available for study that were within the protocol-specified weight range (200-300 g)*. After randomizing, using computer-generated random numbers, the rats were-assigned into this study and to dose groups. The weight variation of the animals selected for the study did not exceed ±20% of the mean body weight of each sex.

Justification of Species Selection
The rat was selected for use on this study because, historically, rats have been used as a representative of a rodent species and are recommended by various regulatory agencies.

In-life Start Date: November 01, 2001
In-life End Date: November 22, 2001

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

Dose Preparation
The test material was mixed with cell culture grade water and stored at room temperature until administration.

Method of Administration
All animals received a single dose of the test material administered by oral gavage. The individual dose volume was based oneach animal's body weight taken just before dosing. Food was withheld from the animals for 17 to 20 hours before and approximately 4 hours after dose administration.

Reason for Dosing Route
Potential human exposure is by the oral route.

Doses:

500, 1000, 2000 mg/kg (limit test)
2000 mg/kg (acute oral test)

No. of animals per sex per dose:

2 (limit test)
5 (Acute Oral test)

Control animals:

no

Details on study design:

Acute Tox test:
Dosing Information. The animals used in the oral toxicity study were dosed on November 07, 2001. At initiation of dosing the males were approximately 8 weeks old and the females were approximately 10 weeks old, with a weight range of 210 to 220 g and 206 to 217 g, respectively. At the termination of this assay, all surviving animals were euthanized with Euthanasia 6, followed by exsanguination, and necropsied.

Mortality
A summary of mortality is presented in Table 5. Two of the five males died on Day 1 and three of the five females died on Day 0 or 1. All remaining animals survived until the scheduled sacrifice.

Clinical Signs
Individual clinical observations are presented in Table 6. Orange urine stains were noted in all animals at 1-hour postdose. Two of the five males died on Day 1 following observations of orange urine and fecal stains, and/or red oral discharge. Three of the five females died on Day 0
or 1 following observations of orange urine and/or fecal stains, red discolored feces, soft feces, hypoactivity, tremors and/or cold to touch. The remaining animals survived until the scheduled sacrifice. Findings included discolored urine and/or feces, urine and/or fecal stains, soft feces, no feces and/or small amounts of feces; these findings continued in some animals through study termination.

Body Weights
Individual and mean body weights and body weight changes are presented in Table 7. All the animals that survived gained weight during the course of the study.

Necropsy
Individual necropsy findings are presented in Table 8. No visible lesions were noted in any of the animals that survived until the study termination. Macroscopic findings in the two male and three female animals that died involved the stomach, intestines, ileum, duodenum, jejunum and/or cecum. Findings noted were distended organs filled with orange lumen fluid in all five animals, and red mucosal surface of the stomach in two males and one female.

Statistics:

N/A

Results and discussion

Preliminary study:

Dosing Information.
The animals used in the dose limit test were dosed on November 01, 2001. At initiation of dosing the animals were approximately 8 weeks old, with a weight range of 233 to 263 g and 162 to 181 g, for the males and females, respectively. At the termination of this assay, all surviving animals were euthanized with Euthanasia 6, followed by exsanguination, and necropsied.

Mortality
Two females, one at the 1000 mg/kg dose level and one at 2000 mg/kg dose level, died on Day 1. All the remaining animals survived until the
scheduled sacrifice.

Clinical Signs
Individual clinical observations are presented in Table 2. Four animals were noted with salivation immediately postdose and these observations were resolved by 2 hours postdose. One female at 1000 mg/kg was noted with red urine and red urine stains, which were resolved by Day 3. One female at 1000 mg/kg was noted with slight hypoactivity and lacrimation at 4 hours post dose and was found dead on Day 1. One female at 2000 mg/kg was noted with salivation immediately postdose, was normal from 2 hours postdose on and was found dead on Day 1. All the remaining animals were normal for the remaining observation periods, with the exception of fecal stains noted in one male in the 2000 mg/kg dose group animal at the Day 2 observation
interval.

Body Weights
All the animals that survived gained weight during the course of the study.

Necropsy
Individual necropsy findings are presented in Table 4. No visible lesions were noted in any of the animals that survived until the scheduled termination. Macroscopic findings in the two female animals that died (one at 1000 mg/kg and one at 2000 mg/kg) involved the stomach, ileum, duodenum, and jejunum. Findings noted were red mucosal surfaces of the stomach, and organs filled with red lumen fluid in both animals and distended stomach in one animal.

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

>= 1 000 - <= 2 000 mg/kg bw

Based on:

test mat.

Mortality:

Two of the five males died on Day 1. Three of the five females died on Day 0 or 1. The remaining animals survived until the scheduled sacrifice.

Clinical signs:

other: Two of the five males died on Day 1 following observations of orange urine and fecal stains, and/or red oral discharge. Three of the five females died on Day 0 or 1 following observations of orange urine and/or fecal stains, red discoloured feces, soft fe

Gross pathology:

Macroscopic findings in the two male and three female animals that died involved the stomach, intestines, ileum, duodenum, jejunum and/or cecum. Findings noted were distended organs filled with orange lumen fluid in all five animals, and red mucosal surface of the stomach in two males and one female.

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

In conclusion, the test item was toxic by the oral route at the 2000 mg/kg dose level under the conditions of this study. The LD50 was estimated to be less than 2000 mg/kg and more than 1000 mg/kg.

Applying the classificaton Regulation (EC) No 1272/2008 the substance is considered to be an acute toxicity category 4 by the oral exposure route.

Executive summary:

In conclusion, the test item was toxic by the oral route at the 2000 mg/kg dose level under the conditions of this study. The LD50 was estimated to be less than 2000 mg/kg and more than 1000 mg/kg.

Applying the classificaton Regulation (EC) No 1272/2008 the substance is considered to be an acute toxicity category 4 by the oral exposure route.