p-tolyl isocyanate

Endpoint summary

Description of key information

Only acute toxicity studies from a secondary source (oral, inhalation, other routes) for p-tolylisocyanate are available. In the acute oral toxicity study a LD50 of ca. 1600 to 3200 mg/kg bw was found.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Dose descriptor:

LD50

Value:

1 600 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Dose descriptor:

LC50

Value:

33 mg/m³ air

Additional information

Only acute toxicity studies from a secondary source (oral, inhalation, other routes) for p-tolylisocyanate are available. In the acute oral toxicity study a LD50 of ca. 1600 to 3200 mg/kg bw was found.

m-tolylisocyanate (structural isomere) is regarded as a structural analogue or surrogate for p-tolylisocyanate and a read-across from this supporting substance is justified due to the close stuctural similarity to the target compound.

m-tolylisocyanate:

In 2 reliable oral toxicity studies a LD50 of 2926 mg/kg bw and 3191 mg/kg bw on male and female rats were found

In a guideline study according OECD 403 for male rats a LC50 = 33 mg/m³ air and for female rats a LC50 = 30 mg/m³ air (analytical vapour concentration) was found.

For acute dermal toxicty no data were available.

p-tolylisocyanate:

In a not assignable study a LD50 = ca. 1600 - 3200 mg/kg bw was determined. In a not assignable study a LC100 < 4.74 mg/l air bw was found. The results correlate with the findings for m-tolyl isocyanate for acute oral toxicity or are are not in contrast to the results of the inhalation study for m-tolyl isocyanate.

Justification for classification or non-classification

For the acute oral toxicity a classification as Xn, R 22 (GHS: Acute Tox. 4, H 302) is justified.

For the acute inhalation toxicity T+, R26 is justified as a result of the LC50 = 30 mg/m³ air