1-chloro-2-nitrobenzene

Endpoint summary

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Dose descriptor:

LD50

Value:

219 mg/kg bw

Acute toxicity: via dermal route

Endpoint conclusion

Dose descriptor:

LD50

Value:

655 mg/kg bw

Additional information

o-Chloronitrobenzene is toxic by oral administration.

In a study performed comparable to guideline study 401 with acceptable restrictions (no pathology performed and lack of details on test substance) the acute oral toxicity of 1 -chloro-2 -nitrobenzene was investigated in male and female Wistar II rats. 7 male and 8 female groups of 15 animals were dosed with 50, 100, 150, 200, 250, 300 and 500 mg/kg bw and 25, 50, 100, 250, 350, 500, 650 and 850 mg/kg bw 1 -chloro-2 -nitrobenzene per gavage and observed for 14 days following exposure for mortality and clinical signs.

Mortalities occurred at dose levels equal to and exceeding 150 mg/kg bw between 24 hours and 2 days after administration in male rats and in female rats at dose levels equal to and exceeding 250 mg/kg bw between 24 hours and 8 days. Reduced general condition and cyanotic appearance were observed in all male animals dosed 100 - 500 mg/kg bw and in all female rats dosed with 50 - 850 mg/kg bw. Symptoms started to appear 8 min (650 mg/kg bw, females) and 24 hours (50 and100 mg/kg bw, females) after administration, continuing up to 13 days. No clinical signs were observed in animals dosed with 25 mg/kg bw in females and 50 mg/kg bw in male rats. The calculated LD50 for male rats was 219 mg/kg bw and 457 mg/kg bw for female rats (Groening, P., Bayer AG, 1976). Another study performed comparable to guideline study 401 with acceptable restrictions leads to LD50 between 251 mg/kg bw for male rats and 263 mg/kg bw for female rats (Loeser, Bayer AG, 1982).

o-Chloronitrobenzene is toxic in contact with skin.

The dermal LD50 range in rat studies was between 655 - 1796 mg/kg bw.

In a study performed comparable to guideline study 402 with acceptable restrictions the acute dermal toxicity of o-chloronitrobenzene

was investigated in 10 male rats. The calculated mean LD50 was 655 mg/kg body weight (Groening, Bayer AG, 1976).

Justification for classification or non-classification

LD50(oral) = 219 mg/kg bw (calculated by Probit-analysis (Fink and Hund 1965. Arzneim.-Forsch. 15:624), Litchfield and Wilcoxon (J. Pharmacol. Exp. Therap. 96, 99, 1949))

Classification:

DSD: Xn, R22 Harmful if swallowed

GHS: Acute Oral Category 3

LD50 (dermal) = 655 mg/kg bw

Classification:

DSD: Xn, R21 Harmful in contact with skin

GHS: Acute Dermal Category 3

According to the OECD SIDS (OECD SIDS Initial Assessment Report, 1-Chloro-2-nitrobenzene, CAS: 88-73-3, UNEP Publications, 2001) there is only one inhalation study which gives sufficient information to evaluate this endpoint. In this rat study the LC50 was 3200 mg/m³ for 4 hours in a vapour/aerosol mixture. For precautionary reasons we recommend classification according to CLP: Acute Inhalation Category 3.