1,2-dichlorobenzene

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2001

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP - guideline study; no deviations mentioned

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

2001

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

no

Remarks:

deviations mentioned

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

1,2-dichlorobenzene

EC Number:

202-425-9

EC Name:

1,2-dichlorobenzene

Cas Number:

95-50-1

Molecular formula:

C6H4Cl2

IUPAC Name:

1,2-dichlorobenzene

Details on test material:

- Name of test material (as cited in study report): o-dichlorobenzene
- Analytical purity: 99.7%
- Lot/batch No.: 8803302

Test animals

Species:

rat

Strain:

Crj: CD(SD)

Sex:

male/female

Details on test animals or test system and environmental conditions:

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23 - 25
- Humidity (%): 50 - 65
- Photoperiod (hrs dark / hrs light): 12 / 12 (light from 7 - 19 o'clock)

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

corn oil

Doses:

Males: 0 (vehicle only), 500, 1000, 2000 mg/kg bw
Females: 2000 mg/kg bw

No. of animals per sex per dose:

5 animals per sex and dose group

Control animals:

yes

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Mortality:

3 deaths occured of male rats given 2000 mg/kg bw.

Clinical signs:

other: Clinical signs of decrease in locomotor activity, adoption of an prone position, tremors, irregular respiration and salivation were observed.

Gross pathology:

At autopsy, pale discoloration of the liver and accumulation of dark colored fluid in th urinary bladder were observed in dead animals.

Other findings:

- Histopathology: The liver showed degeneration and/or necrosis of hepatocytes accentuated in the centrilobular area in dead animals and centrilobular hypertrophy of hepatocytes in a surviors.

Any other information on results incl. tables

Table 1: Mortality of rats treated with o-dichlorobenzene in the single dose oral toxicity study

Sex	Dose	No. of	Number of animals died in corresponding time period after administration										Mortality (a)
	mg/kg bw	animals	0 -1 h	1 -2h	2 -3 h	3 -4 h	4 -5 h	5 -6 h	2 days	3 days	4 days	5 -15 days
Male	0	5	0	0	0	0	0	0	0	0	0	0	0 / 5
	500	5	0	0	0	0	0	0	0	0	0	0	0 / 5
	1000	5	0	0	0	0	0	0	0	0	0	0	0 / 5
	2000	5	0	0	0	0	0	0	1	1	1	0	3 / 5
female	2000	5	0	0	0	0	0	0	0	0	0	0	0 / 5

(a) : Number of animals died / Number of animals examined

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

A single dose oral toxicity study of 1,2-dichlorobenzene was conducted according to OECD guideline 401. The LD50 values were estimated to be greater than 2000 mg/kg for males and females.

Executive summary:

Nagata et al., 2001

A single dose oral toxicity study of 1,2-dichlorobenzene was conducted according to OECD guideline 401. The GLP study was considered to be reliable because no deviations were mentioned.

Male Crj: CD(SD) rats were dosed with 0 (vehicle only), 500, 1000, or 2000 mg/kg bw of 1,2-dichlorobenzene. In addition, female Crj: CD(SD) rats were administered 2000 mg/kg bw in order to show that there were no gender-specific differences. According to guideline, 5 animals per dose group and sex were used.

Deaths occured of male rats given 2000 mg/kg bw. Clinical signs of decrease in locomotor activity, adoption of a prone position, tremors, irregular respiration and salivation were observed. Body weights of the treated animals were dose dependently lower than those of the control group. At autopsy, pale discolorationof the liver and accumulation of dark colored fluid in the urinary bladder were observed in dead animals. histopathologically, the liver showed dageneration and /or necrosis of hepatocytes accentuated in the centrilobular area in dead animals and cnetrilobular hypertrophy of hepatocytes in a survivors.

The LD50 values were estimated to be greater than 2000 mg/kg for males and females.