Cumene

Endpoint summary

Description of key information

For acute oral toxicity an LD50 of 2260 mg/kg bw is available. Data on inhalation toxicity revealed an LC50 >17.6 mg/L (=g/m3). And for dermal toxicity an LD50 >3160 mg/L was derived.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Dose descriptor:

LD50

Value:

2 260 mg/kg bw

Additional information

Data on acute toxicity are presented in Section 4.1.2.2.1 of the EU RAR (2001; Section 4.1.2.6, page 57ff).

 

For the acute toxicity of cumene no guideline studies performed under GLP are available. However, the data presented in a weight of evidence approach are sufficient for the assessment and for classification and labelling purposes.

 

ACUTE ORAL TOXICITY

For acute oral toxicity LD50 values between 1400 and 4000 mg/kg bw have been reported in rats. Symptoms of toxicity included central nervous depression. Post mortem examination showed haemorrhagic lungs, liver discoloration and acute gastrointestinal inflammation. As most relevant studies for this endpoint a LD50 of 2260 mg/kg bw obtained in rats by Ciba Geigy (1985; see robust study summaries in IUCLID section 7.2.1) and an LD50 of 2700 mg/kg bw obtained in rats by Monsanto (1978, see robust study summaries in IUCLID section 7.2.1) have been selected.

 In the EU RAR the results of five other studies with rats are reported, which support the findings listed above.

Based on the viscosity, the substance is classified for aspiration.

 

ACUTE INHALATION TOXICITY

Due to the volatility of cumene, the inhalation route may be the most important for assessment. After a 6 h exposure no death occurred at a concentration of 17.6 mg/L (Monsanto Corporation 1978, see robust study summaries in IUCLID section 7.2.2), but 4 of 6 deaths were observed after a 4 h exposure to 39.2 mg/L (Smyth et al. 1951, see robust study summaries in IUCLID section 7.2.2). For mice a LC50 of 10 mg/L has been obtained after nose only exposure for 7 h (Werner et al. 1944, see robust study summaries in IUCLID section 7.2.2). The principal causes of death in acutely exposed animals were respiratory paralysis, pulmonary oedema and haemorrhaging associated with further haemorrhage in the thymus, bladder and adrenals.

Therefore, a LC50 of >17.6 mg/L can be derived from the data available. This value indicates a low acute toxicity in animals.

 

Other studies are available in the EU RAR with rats and mice, which support the findings listed above. Results in mice leads to the conclusion that the neurobehavioral effects are comparable to those observed with phenobarbital.

 

ACUTE DERMAL TOXICITY

After dermal exposure of 3160 mg/kg bw no deaths were observed in rabbits (Monsanto, 1978, see robust study summaries in IUCLID section 7.2.3). Therefore, an LD50 of >3160 mg/kg bw can be derived. Other investigations revealed an LD50 10600 mg/kg bw (Smyth et al. 1951, see robust study summaries in IUCLID section 7.2.3), while Ciba Geigy (1985, see robust study summaries in IUCLID section 7.2.3) reported an LD0 of 10000 mg/kg bw. Weight loss, increasing weakness, collapse and death were observed. Gross autopsy showed haemorrhagic areas of the lungs, liver discoloration, darkened kidneys and spleen and gastrointestinal inflammation.

 

No further studies were listed in the EU RAR.

Justification for classification or non-classification

Based on the information from acute toxicity tests, there is no need to classify cumene as toxic.