2-methylpent-2-enal

Endpoint summary

Description of key information

Oral: The acute oral LD50 was determined to be 4290 mg/kg bw in rats. 
Dermal: The acute dermal LD50 was determined to be 4000 mg/kg bw  in rabbits.
Inhalation: The acute inhalation LC50 was determined to be 8100 mg/m³ air/4 h in rats.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Dose descriptor:

LD50

Value:

4 290 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Dose descriptor:

LC50

Value:

8 100 mg/m³ air

Acute toxicity: via dermal route

Endpoint conclusion

Dose descriptor:

LD50

Value:

4 000 mg/kg bw

Additional information

Oral:

The test article 2-methyl-2-pentene-1-al was administered by gavage to five male Wistar rats in five dose groups in a logarithmic series, weighing 90 to 120 g after fasting. Study duration was 14 days. The oral LD (males) was determined to be 4290 mg/kg bw, with 95 % fiducial limits of 3070 – 5980 mg/kg bw. LD50 values and their fiducial range are estimated by the method of Thompson (1947) using the tables of Weil (1952). No information is given on mortality patterns, signs of toxicity , or necropsy (Smyth, 1954).

Dermal:

The test article 2-methyl-2-pentene-1-al was administered to groups of four male New Zealand White rabbits weighing 2.5 to 3.5 kg. The test material was applied to the shaved intact skin of the animals, covering 1/10 of the entire trunk area. The test article was retained beneath an impervious plastic film. After 24 hours contact the film was removed, and mortality was considered complete after 14 additional days. The test item showed a median LD50 of 4.5 mL/kg , corresponding to 4000 mg/kg bw. The 95 % fiducial limits were 2.0 – 9.8 mL/kg, corresponding to 1960 – 8624 mg/kg bw (assuming a density of abt. 0.9 g/mL of the test material) (Smyth, 1954).

Inhalation:

In an acute inhalation toxicity study, one group of rats (6 males) were exposed by inhalation route to concentrations of 2-methyl-2-pentene-1-al in essentially logarithmic series with a factor of 2 for 4 hours at 20°C. Animals then were observed for 14 days. During the 14 days observation period, 3/6 animals died at a concentration of 2000 ppm (corresponding to 8100 mg/m³ air). No death occurred during 1 h concentrated vapour inhalation by rats. No detail on clinical/mortality signs is given (Smyth, 1954).

 

Justification for classification or non-classification

No classification and labelling for acute oral and dermal toxicity is necessary according to Directive 67/548/EEC(DSD) or Regulation (EC) No 1272/2008 (GHS (EU-CLP)) criteria. For inhalation toxicity, the substance was classified Xn, R20 - Harmful by inhalation according to Directive 67/548/EEC (DSD), and acute toxic, cat 3 (Inhalation, vapour) according to Regulation (EC) No 1272/2008 (GHS (EU-CLP)) criteria.