4-tert-butylbenzaldehyde

Endpoint summary

Description of key information

Acute Oral Toxicity, rat: LD50 = 50.6 mg/kg bw (BASF79/168)
Acute dermal toxicity, Rabbit: LD 50 > 2000 mg/kg bw (BASF79/168)

Additional information

There are valid studies available for the assessment of the acute toxicity of t-butyl-benzaldehyde.

 

Oral:

In an acute oral toxicity study according to OECD TG 401 and GLP, five female Fü-albino SPF rats per dose group were treated with 200, 500 or 800 mg/kg bw (Givaudan 1990). One animal treated with 800 mg/kg bw died on the first test day. A depressed body weight development was observed in rats treated with 800 mg/kg bw. Clinical findings were diarrhea, soiled urogenital region and piloerection. No gross lesions were observed. The oral LD50 is > 800 mg/kg bw in this study.

In an acute oral toxicity study, i.e. a BASF test similar to OECD TG 401, five male and five female Sprague Dawley rats per group were treated with 14.7, 21.5, 31.6, 46.4 and 68.1 mg/kg bw under standardized conditions (BASF79/168). The animals were observed for 14 d, necropsy was performed even with the survivors. The LD50 was 50.6 mg/kg bw for male and female rats. None of the test animals died within the first 24 h after administration of the test material. Clinical signs of toxicity included dyspnoe, apathy, abnormal position, staggering, atony, narcotic, no pain and no corneal reflex, spastic movement, ruffled fur, diarrhea, cyanosis, exsiccosis, exophtalamus and a generally bad condition. At gross necropsy, acute dilatation on the right side and an acute congestion hyperemia was seen in the heart of the animals that died during the study; the liver was clay-like coloured due to slightly broadened Lobuli hepatici and the kidneys were brightened (nephrosis). No substance-related effects were seen in the sacrificed animals.

In two other acute oral toxicity studies using Charles River rats, beeing available als short summary from secondary sources, the LD50 values were determined to be >487 and <973 mg/kg bw or >800 and <1000 mg/kg bw after a 7 day observation period (TSCATS-OTS0510296; TSCATS-OTS0510298).

Overall, contradictive results are available for acute oral toxicity. However in a weight of evidence, the lowest LD50 determined will be used as the basis for the decision on classification of t-butyl-benzaldehyde.

Inhalation:

In a standardized inhalation hazard test 12 rats were exposed for 7 hours to an atmosphere that had been saturated at 20 °C with the volatile parts of the test compound (vapour) (BASF79/168). 0/12 rats died after 7 h exposure and no clinical signs were observed. At gross necropsy nothing abnormal was detected. The test concentration, i.e. 0.142 mg/l, has been determined by calculated of the substance weight loss and cumulative air flow during study (no analytical verification has been performed).

 

Dermal:

In the key study, i.e. an internal BASF test similar to OECD TG 402, p-tert-butylbenzaldehyde was administered dermally at doses of 200, 400, 1000 and 2000 mg/kg bw to 3 male and 3 female rats per dose group (BASF79/168). 1/6 animals of the 2000 mg/kg dose group died within the first two days. All other animals survived. Clinical signs of toxicity included dyspnea, apathy, aggressiveness, excitation, staggering, tremor, spastic movement, morphine tail, diarrhea and a generally bad condition. At gross necropsy, an acute dilatation on the right side as well as an acute congestion hyperemia of the heart was seen in the one animal that died during the study. Additionally, acute and moderate exhalation of the lung and brightened, clay-like coloured, broadened lobuli hepatici were seen in the liver. No substance-related effects were seen in all sacrificed animals. Reversible dermal irritation effects were observed.

Overall, the available data for p-tert-butylbenzaldehyde indicate a potential for acute toxicity, depending on the route of exposure.

Justification for classification or non-classification

The present data on acute oral toxicity do fulfill the criteria laid down in 67/548/EEC and 1272/2008/EEC, and therefore, a classification as "Toxic if swallowed" (R25 or Category 3) is warranted.

The present data on acute dermal toxicity do not fulfill the criteria laid down in 67/548/EEC and 1272/2008/EEC, and therefore, a non-classification is warranted. According to UN-GHS, the test substance needs to be classified as acute dermal toxicant (Category 5).