1,2-dichlorobenzene

Endpoint summary

Description of key information

ORAL EXPOSURE:
A single dose oral toxicity study of 1,2-dichlorobenzene was conducted according to OECD guideline 401 (Nagata et al., 2001). The LD50 values were estimated to be greater than 2000 mg/kg for males and females. Older studies found lower LD50 values. According to the harmonised classification - Annex VI of Regulation (EC) No 1272/2008 (CLP regulation) 1,2-dichlorobenzene is classified as Acute Tox. 4* (H302: Harmful if swallowed).

INHALATIVE EXPOSURE
There are several limited acute inhalation toxicity studies available. Based on a weight-of-evidence approach and according to CLP classification criteria (Regulation (EC) No 1272/2008) a classification as Acute Tox 4 ( H332: Harmful if inhaled.) is proposed.

DERMAL EXPOSURE
No data available

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Quality of whole database:

A single dose oral toxicity study of 1,2-dichlorobenzene was conducted according to OECD guideline 401 (Nagata et al., 2001). The LD50 values were estimated to be greater than 2000 mg/kg for males and females. Older studies found lower LD50 values. According to the harmonised classification - Annex VI of Regulation (EC) No 1272/2008 (CLP regulation) 1,2-dichlorobenzene is classified as Acute Tox. 4* (H302: Harmful if swallowed).

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Quality of whole database:

There are several limited acute inhalation toxicity studies available. Based on a weight-of-evidence approach and according to CLP classification criteria (Regulation (EC) No 1272/2008) a classification as Acute Tox 4 ( H332: Harmful if inhaled.) is proposed.

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

ORAL EXPOSURE:

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 occurred 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 discoloration of the liver and accumulation of dark colored fluid in the urinary bladder were observed in dead animals. Histopathologically, the liver showed degeneration and /or necrosis of hepatocytes accentuated in the centrilobular area in dead animals and centrilobular hypertrophy of hepatocytes in a survivors.

The LD50 values were estimated to be greater than 2000 mg/kg for males and females. Hence, the test requires no classification according to EU-GHS.

INHALATIVE EXPOSURE (weight of evidence approach):

Bonnet, 1982

An acute toxicity study had been conducted on male rats. The reliability is not assignable because the publication is not translated. The LC50 was determined by inhalative exposure of male SD rats for 6 h. The concentrations (1383-1730 ppm) of the vaporised 1,2-dichlorobenzene were analysed regularly. A LC50 of 1532 ppm (9.36 mg/L) was stated. After conversion, the LC50 for 4h was 14.04 mg/L (2298 ppm), which results in an EU-GHS classification "Toxicity Category IV".

Bonnet, 1979

An acute toxicity study had been conducted on female mice. The reliability is not assignable because the publication is not translated. The LC50 was determined by inhalative exposure of female OF1 mice for 6 h. The concentrations (1201 - 1279 ppm) of the vaporised 1,2-dichlorobenzene were analysed regularly. A LC50 of 1236 ppm (7.55 mg/L) was stated. After conversion, the LC50 for 4h was 1854 ppm which results in an EU-GHS classification "Toxicity Category IV".

Justification for classification or non-classification

Acute oral toxicity: According to the harmonised classification - Annex VI of Regulation (EC) No 1272/2008 (CLP regulation) 1,2-dichlorobenzene is classified as Acute Tox. 4* (H302: Harmful if swallowed).

Acute inhalation toxicity: Due to a weight of evidence consideration of the results of the acute inhalation studies, and according to CLP classification criteria (Regulation (EC) No 1272/2008) a classification as Acute Tox 4 ( H332: Harmful if inhaled.) is proposed.