2-(4-tert-butylbenzyl)propionaldehyde

Endpoint summary

Description of key information

Key study for acute oral toxicity (rat): LD50 1390 mg/kg
Key study for acute dermal toxicity (rat): LD50 >2000 mg/kg
Supportive study for acute dermal toxicity (rabbit): LD50 >5000 mg/kg

Additional information

Acute toxicity: oral

In the chosen key study, 5 rats per dose group were treated by a single dose via gavage with lysmeral in carboxymethyl cellulose (681; 1000; 1470; 2150; 3160 mg/kg bw) and animals were observed for a period of 14 days for mortality, clinical signs of toxicity, body weight and were subjected to necropsy (BASF AG 79/166). Mortality was observed, starting 1 day after application of the test substance and clinical signs of toxicity, i.e. poor general state, rough fur coat, drunken and spastic gait, dyspnea, apathy and abnormal position were observed in all dose groups. The derived LD50 was 1390 mg/kg bw.

Further data on acute oral toxicity in rats are available as short summaries from secondary sources, providing limited information on study details. LD50 were reported to be 3700 mg/kg bw using 10 animals per dose (Moreno 1977), >20 ml/kg bw using 10 animals in a single dose group (EPA (TSCAT) 1991A).

Acute toxicity: inhalation

No key study is available for this toxicological endpoint.

In an inhalation hazard test, 6 rats were exposed to an atmosphere saturated with lysmeral at 20 °C for 7 hours (BASF AG 79/166

). No mortality, clinical signs of toxicity or organ anomalies were observed up to 14 days after exposure. However, given that lysmeral has a low volatility, assessment of inhalation toxicity on the basis of this study is limited.

Acute toxicity: dermal

In the key study, 3 rats were treated by a single dermal (occlusive) application of lysmeral (2000 mg/kg bw) in carboxymethyl cellulose and animals were observed for a period of 14 days for mortality, body weights, clinical signs of toxicity and gross pathology (BASF AG 79/166

). No mortality was observed, and clinical signs of toxicity, i.e. dyspnea, agitation, apathy, staggering, rough fur coat, lacrimation, poor general condition and slight erythema/edema followed by desquamation were reversible within the observation period. The derived LD50 was > 2000 mg/kg bw.

In a supportive study in rabbits, available as short summaries from a secondary source with limited information on study details, 10 animals were treated by a single dermal (occlusive) application of 5000 mg/kg bw lysmeral, showing no mortality (Moreno 1977). The LD50 was set as > 5000 mg/kg bw.

According to further data from secondary sources with limited information on study details, no mortality was observed after dermal application of 2 ml/kg bw on 6 rabbits (EPA (TSCAT) 1991B).

Justification for classification or non-classification

Based on the findings for acute oral toxicity, i.e. an LD50 of 1390 mg/kg bw in the chosen key study, lysmeral has to be classified as harmful after single oral exposure (R22) according to the criteria laid down in 67/548/EEC or acute toxicant (category 4) according to GHS-CLP.

Based on an inhalation hazard test, no mortality was observed after inhalation of a saturated vapor–air mixture.

Based on the findings for acute dermal toxicity, i.e. an LD50 above 2000 mg/kg bw in the chosen key study, the substance does not fulfill the criteria laid down in 67/548/EEC or GHS-CLP and a non-classification is warranted.