Triethoxy(3-isocyanatopropyl)silane

Endpoint summary

Description of key information

No specific test data for skin sensitisation are available for triethoxy(3-isocyanatopropyl)silane. However, isocyanates are known skin sensitisers with many references in the open literature (see for example the HSDB database). It is therefore reasonable to conclude that triethoxy(3-isocyanatopropyl)silane could cause skin sensitisation.

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

There is good evidence to indicate that isocyanates: cause chemical bronchitis/pneumonitis; are potent pulmonary sensitisers capable of causing “isocyanate asthma”; cause nonspecific airways disease, including chronic bronchitis; can induce a general asthmatic state; and can cause hypersensitivity pneumonitis. Similar dose-response relationships are seen for both acute and chronic effects (Musk et al., 1988).

American Journal of Industrial Medicine, Vol 13, Issue 3, pages 331-349

Isocyanates cause asthma, the symptoms of which include coughing, shortness of breath, wheezing, and chest tightness. Symptoms can occur soon after exposure or several hours later. Isocyanates can also cause hypersensitivity pneumonitis, a lung disease whose symptoms include fever, body aches, shortness of breath, and cough with phlegm or sputum. About one out of twenty people who work with isocyanates becomes "sensitised" to them. Being "sensitised" to isocyanates means an asthma attack may occur at any time when expose occurs, even to extremely small amounts. Sensitivity to isocyanates can be permanent. Also, continuing to work with isocyanates after becoming sensitised can cause asthma itself to become permanent, so that attacks can occur even without any further exposure to isocyanates. Once sensitised, an individual cannot continue to work in any job where expose to isocyanates is possible. It is possible to become sensitised to isocyanates without ever having had any other symptoms of overexposure. There is no evidence that people with other allergies are more likely to become sensitised to isocyanates. Daily exposure to levels of isocyanates too low to cause sensitisation or cause asthma or pneumonitis may still cause a reduction in lung capacity and function ((http://www.cdph.ca.gov/programs/hesis/Documents/iso.pdf).

Data for the hydrolysis product, 3-aminopropyl(triethoxy)silane (CAS 919-30-2), have been added to the dataset as supporting information for completeness, but are not used in the assessment as the skin and respiratory sensitisation potential of the parent substance are determined by the isocyanate group.

Justification for classification or non-classification

Based on data for isocyanates, triethoxy(3-isocyanatopropyl)silane requires classification for skin sensitisation Cat 1A and respiratory sensitisation Cat 1A with hazard statements 'H317: May cause an allergic skin reaction' and 'H334: May cause allergy or asthma symptoms or breathing difficulties if inhaled' according to Regulation (EC) No 1272/2008. The intermediate hydrolysis product 3-aminopropyl(triethoxy)silane is also classified as Skin Sensitiser Cat 1B according to Regulation (EC) No 1272/2008, as amended, on the basis of reliable measured data (Pharmakon USA, 1997).