Chloroform

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

publication

Title:

The acute toxicity of four trihalomethanes in male and female rats

Author:

Chu I, Secours V, Marino I, Villeneuve D

Year:

1980

Bibliographic source:

Toxicology and Applied Pharmacology 52, 351-353

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Chloroform

EC Number:

200-663-8

EC Name:

Chloroform

Cas Number:

67-66-3

Molecular formula:

CHCl3

IUPAC Name:

trichloromethane

Details on test material:

Chloroform of purity > 99 % obtained from Caledon Chemicals, Georgetown, Ontario, Canada

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

Biobreeding Labs, Ottawa, Ontario, 150-200 g, acclimated for 1 week, temperature 21 +/- 2 °C, humidity 40-70 %, caged individually and allowed free access to food and water

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

administration at a constant volume of 5 mL/kg, animals were fasted overnight before dose administration

Doses:

546, 765, 1071, 1500, 2100 mg/kg body weight

No. of animals per sex per dose:

10 males, 10 females

Control animals:

no

Details on study design:

To establish the dose levels to be used in the LD50 studies, groups of two animals were administered test compounds at 250 and 3000 mg/kg and the mortality data were recorded. Then, the main LD50 studies were carried out with doses of 546-2100 mg/kg using 10 female and 10 male rats. Clinical observations were made for 14 days after dosing and a postmortem examination was performed on animals which died during this period. All surviving animals were killed at the end of 14 days and subjected to gross pathologic examination.

Statistics:

Statistical analysis of data was carried out using one-way analysis of variance and the Student-Newman-Keuls test. LD50 values were calculated using the probit analysis (Finney 1952).

Results and discussion

Effect levels

Effect levels 1

Sex:

male

Dose descriptor:

LD50

Effect level:

908 mg/kg bw

95% CL:

750 - 1 082

Effect levels 2

Sex:

female

Dose descriptor:

LD50

Effect level:

1 117 mg/kg bw

95% CL:

843 - 1 514

Mortality:

See also Table 1: At the highest dose level, 4 males died within 24 hours after dosing and most animals were dead after 4 days post-administration. At lower doses animals died primarily on Day 3 to Day 4 post-administration.

Clinical signs:

other: Common clinical signs consisted of piloerection, sedation, flaccid muscle tone, ataxia, and prostration. Chloroform elicited dacryorrhea in some animals.

Gross pathology:

Increased relative weights of the liver and the kidneys. For lesions see Table 2

Other findings:

A clear trend towards increased cholesterol levels was seen in all treated animals. Inhibition of lactate dehydrogenase activities were seen in all treated groups. A significant decrease in the levels of liver proteins were observed in rats fed chloroform. Microsomal hydroxylase activity of female but not male rats was activated by administration of chloroform. A reduction in lymphocytes with significant decreased was noted in female rats. Decrease in haemoglobin and haematocrit values were observed in males and females fed chloroform.

Any other information on results incl. tables

Table 1: Mortality occurring in the acute oral toxicity study:

Dose (mg/kg)	Sex	Total animals dead*	Survival time (days after oral administration)							LD50 (mg/kg)
			1	2	3	4	5	6	7
546	Male	0	--	--	--	--	--	--	--	M:908(750-1082) F:1117(843-1514)
	Female	1	--	--	1	--	--	--	--
765	Male	5	1	--	1	1	2	--	--
	Female	3	--	--	1	2	--	--	--
1071	Male	6	2	--	2	--	2	--	--
	Female	6	--	2	2	--	--	2	--
1500	Male	9	--	--	5	1	2	1	--
	Female	5	--	1	3	1	--	--	--
2100	Male	10	4	--	3	1	1	1	--
	Female	9	--	--	4	5	--	--	--

*Animals dying before the end of the 14 day observation period

Table 2: Incidence of histological changes of rats which survived single oral doses of chloroform

Doses (mg/kg)	Liver		Kidneys
	Males	Females	Males	Females
546	0/2	1/2	02	0/2
765	2/2	0/2	1/2	1/2
1071	--	0/2	--	2/2
1500	0/1	0/2	0/1	1/2
2100	--	0/1	--	0/1

Numbers denote: number of animals showing lesions/animals examined

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

Remarks:

Migrated information

Conclusions:

Based on the results of this study in the rat, chloroform is classified as harmful if swallowed.

Executive summary:

The acute oral toxicity of chloroform, solubilised in corn oil, was tested in female and male Sprague-Dawley rats (10 animals per dose group) in accordance with the OECD Guideline No. 401 with minor restrictions. Chloroform was administered at doses of 546, 765, 1071, 1500 and 2100 mg/kg body weight by oral gavage. Animals were then observed for 14 hours, clinical signs were noted and animals which were dying during the observation period or were killed after 14 days were submitted to necropsy and gross pathology. The mean LD50 values determined for male rats was 908 mg/kg body weight, that of female rats was 1117 mg/kg. Following the GHS classification system, chloroform on the basis of the present study is classified into Toxicity Category IV, receiving the hazard statement "harmful if swallowed".