Trichlorosilane

Endpoint summary

Description of key information

There are no reliable in vivo or in vitro skin and eye irritation/corrosion data available for trichlorosilane. However, based on the fact that this substance is a chlorosilane, and generates hydrogen chloride in the presence of moisture, it is expected to be corrosive. Therefore, in accordance with Column 2 of REACH Annex VIII, the in vitro skin irritation study and eye irritation study (required in Section 8.1.1 and 8.2.1) do not need to be conducted as the available information indicates that the substance meets the criteria for classification as corrosive to skin.

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

no study available

Eye irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Trichlorosilane hydrolyses rapidly (half-life < 0.3 minutes at pH7) in contact with water and moist air, releasing 3 moles of hydrogen chloride (HCl) for each mole of parent material. Although no reliable skin and eye irritation/corrosion studies are available, severe skin, eye and respiratory damage can be expected due to release of HCl. This is consistent with reliable measured data for other chlorosilanes (PFA, 2013b).

In a supporting in vivo skin irritation toxicity study, not conducted according to OECD Test Guideline or GLP, an erythema/oedema score of 2 out of a maximum of 5 was reported in a summary table of results of a rabbit belly vesicant tests (Mellon Institute, 1951).

 

In a supporting in vivo eye irritation study, not conducted according to OECD Test Guideline or GLP, immediate evident eye injury was seen in rabbits following 3-minutes exposure to vapours of trichlorosilane at a nominal concentration of 1000 or 500 ppm. Delayed eye damage was observed following exposure to 250 ppm. (Union Carbide, 1986).

In another supporting in vivo eye irritation study, not conducted according to OECD Test Guideline or GLP, 5% dilution in "Deobase" (deodorized kerosene) ruined rabbit eyes whereas 1% dilution produced minor damage. The compound was relegated to grade 9 in a 10-grade rating system for eye burns. A 3-minute exposure of rabbit eyes to 500 ppm of vapor produced immediate opacity of the cornea. A concentration of 250 ppm gave no damage that was immediately detectable, but which become apparent 3 hours later and considered as a delayed burn (Mellon Institute, 1951).

Justification for classification or non-classification

Based on the available data, trichlorosilane is classified for skin corrosion Cat 1A and eye damage Cat 1, H314: " Causes severe skin burns and eye damage" according to Regulation (EC) No. 1272/2008. There are no specific data for respiratory irritation, however, there is an acute inhalation study (see chapter 2.3.1). The gross pathology examination in this key acute inhalation study revealed signs of respiratory irritation/corrosion. Therefore, the hazard statement 'EUH071 Corrosive to the respiratory tract' is also applied.