1,1-dichloroethylene

Endpoint summary

Description of key information

The acute toxicity of 1,1-dichloroethene is characterised by a oral LD50 value in rats of 1500 mg/kg bw  and by an inhalation LC50 value in rats 28350 mg/m3. Information allowing to estimate the effect level of the dermal acute toxicity could not be retrieved. 

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Dose descriptor:

LD50

Value:

1 500 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Dose descriptor:

LC50

Value:

28 350 mg/m³ air

Additional information

For acute oral toxicity, 7 studies were available: 4 conducted with rats and 3 with mice. Whereas mice are more sensitive than rats to 1,1-dichloroethylene, the LD50 value obtained from the rat studies was considered as the most relevant as acute studies with rats are considered as more robust or most representative of the toxicity observed in humans. The rat studies showed consistently LD50 values ranging from >1000 mg/kg (NTP study, 1982) to 2500 mg/kg (Kennedy et al. 1991). The lowest LD50 value for rats was selected for classification, i.e. 1500 mg/kg in female rats as observed by Ponomarkov et al. (1980)

For acute dermal toxicity, no results were found in the literature.

For acute inhalation toxicity, 10 studies were available: 6 conducted with rats, 2 with mice and 2 with hamsters. Whereas mice and hamsters are more sensitive than rats to 1,1-dichloroethylene, the LC50 obtained from the rat studies was considered as the most relevant as acute studies with rats are considered as more robust or most representative of the toxicity observed in humans.

The lowest LC50 reported for rats was 28350 mg/m³/4 h (Zeller and Klimish, 1979b).

Justification for classification or non-classification

Taking the oral LD50 value of 1500 mg/kg body weight into account, the substance should be classified as category 4, H302: harmful if swallowed according to EU regulation 1272/2008 on classification, labelling and packaging of substances and mixtures.

Considering the inhalation LC50 value of 28350 mg/m3, no classification is required. Nevertheless, a harmonised classification exists for 1,1 -dichloroethene in Annex VI of EU regulation 1272/2008 on classification, labelling and packaging of substances and mixtures stating that it should be classified as acute toxicity cat. 4, H332 Harmful if inhaled.

No data on acute dermal toxicity is available and the LD-50 values for oral and inhalation acute toxicity are relatively close to the upper limit of the classification scale (2000 mg/kg, 2000 mg/m3). Moreover the nature of the substance (high volatility) makes the complete adsorption of the substance after dermal exposure unlikely. Therefore 1,1 -dichloroethene is not classified for acute dermal toxicity.

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