Chlorothalonil

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

01 Feb 2000 to 07 Mar 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Version / remarks:

1998

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Chlorothalonil

EC Number:

217-588-1

EC Name:

Chlorothalonil

Cas Number:

1897-45-6

Molecular formula:

C8Cl4N2

IUPAC Name:

tetrachlorobenzene-1,3-dicarbonitrile

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: young adult
- Weight at study initiation: males: 231 - 257 g; females: 153 - 199 g
- Housing: singly housed in a suspended stainless steel caging with mesh floors
- Diet: rodent chow
- Water: filtered tap water, ad libitum
- Acclimation period: 10 - 14 days

ENVIRONMENTAL CONDITIONS
- Temperature: 18 - 21 °C
- Photoperiod (hrs dark / hrs light): 12 hour light/dark cycle

IN-LIFE DATES: From: 01 Feb 2000 To: 07 Mar 2000

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Remarks:

1% w/v aqueous

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 30 %

MAXIMUM DOSE VOLUME APPLIED: 5000 mg/kg bw

Doses:

5000 mg/kg bw

No. of animals per sex per dose:

6 females and 5 males

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: observation daily; body weight prior to test substance administration (initial) and again on Days 7 and 14.
- Necropsy of survivors performed: yes (Day 14). Gross necropsies were performed on all animals. Tissues and organs of the thoracic and abdominal cavities were examined .
- Clinical signs including body weight: gross evaluation of skin and fur, eyes and mucous membranes, respiratory, circulatory, autonomic and central nervous systems, somatomotor activity and behaviour pattern. Particular attention was directed to observation of tremors, convulsions, salivation, diarrhea and coma

Results and discussion

Preliminary study:

Female - Range Finding Screen - 5000 mg/kg bw
The female survived and gained body weight during the 7-day observation period. There were no signs of gross toxicity, adverse pharmacologic effects or abnormal behaviour.

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Remarks on result:

not determinable due to absence of adverse toxic effects

Mortality:

No mortality observed.

Clinical signs:

other: With the exception of ano-genital staining, soft faeces and/or diarrhea noted in all rats within 2 hours (in females) and 20 hours (in males) and Day 1 post-dosing, all animals appeared active and healthy over the 14-day observation period. There were no

Gross pathology:

No gross abnormalities were observed.

Any other information on results incl. tables

Table 1. Weight changes in animals treated with 5000 mg/kg bw test substance.

Animal	Sex	Body weight (g)
		Initial	Day 7	Day 14
1	F	162	200	233
2	F	159	202	239
3	F	170	207	246
4	F	167	205	224
5	F	153	194	209
6	M	257	307	350
7	M	232	318	353
8	M	231	308	343
9	M	242	325	366
10	M	233	290	315

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Based on the findings from the study performed in compliance with GLP and following the OPPTS 870.1100 guideline, the acute oral LD50 of the test substance is greater than 5000 mg/kg bw of the test substance in both the male and female rat.

Executive summary:

An acute oral toxicity test was conducted in compliance with GLP and following the OPPTS 870.1100 guideline using rats to determine the potential for the test substance to produce toxicity via the oral route. Based on the results of this study, the acute oral LD50 of the test substance is greater than 5000 mg/kg of body weight in both the male and female rat. Initially, five thousand milligrams of the test substance per kilogram of body weight was administered to one healthy female rat by oral gavage. This animal was observed for 7 days. Due to the absence of mortality in this animal, a group of five females was administered the test substance at the same dose level. Since no females died, a group of 5 males was administered the test substance at 5000 mg/kg to assure that males were not the more sensitive sex. All animals were observed for mortality, signs of gross toxicity, and behavioural changes at least once daily for 14 days. Body weights were recorded prior to administration and again on Days 7 and 14 (termination). Necropsies were performed on all animals at terminal sacrifice.

In conclusion, the LD50 is greater than 5000 mg/kg bw for males and females.