Registration Dossier

Administrative data

Description of key information

Test data on the irritation properties of amorphous silica, which can be used for read-across, do not show eye or skin irritation.

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Eye irritation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Irritation tests have not been performed with silicon.

There are data available on the irritant properties of synthetic amorphous silica. The surface of silicon is composed of a thin oxidized silicon layer resembling the surface of amorphous silicon dioxide. Both silicon and amorphous silica release silicon from particles. The in vitro data on the dissolution kinetics of silicon in different artificial biological fluids shows that the solubility of silicon in biological media is similar or lower than that of amorphous silicon dioxide and it is justified to use read-across from amorphous silicon dioxide to silicon. A detailed description of the justifications for read-across is available in Section 13 of the Iuclid dossier.

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According to available data, synthetic amorphous silica and silicates are not irritating to skin and eyes under experimental conditions. Industrial data presented in OECD (2004a) describes dryness of the skin in workers with chronic contact with precipitated amorphous silica. No cases of skin or eye irritation have been reported in literature from the ferrosilicon/ silicon manufacturing industry or on the use of silica fume. Altogether, there is no reason to believe that silicon would differ in this respect from the sparsely soluble amorphous silicon dioxide.

Conclusion: Silicon is not likely to be a skin or eye irritant. No classification or further testing is proposed. Naturally, like any other dusts, the dusts of silicon may also cause mechanical irritation of the eye and respiratory tract.

Justification for classification or non-classification

Read-across to synthetic amorphous silica: irritation tests with synthetic amorphous silica are negative.