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Physical & Chemical properties

Vapour pressure

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Description of key information

=< 0.751 Pa at 20 °C (Modified Grain method)

Key value for chemical safety assessment

Additional information

Since the substance decomposes during melting, the boiling point or vapour pressure measurements are technically complicated. The QSAR calculation of vapour pressure was performed using the Modified Grain method. This is in compliance with Grain-Watson method, applied for the most substances of the Alkyl Sulfate category.

The calculation is based on the lowest possible boiling temperature, which in fact is probably a decomposition temperature. In a peer reviewed SIDS Initial Assessment Profile for alkyl sulfates it is stated that: "As ionic substances, all members of this category have extremely low vapour pressures. Calculated values are in the ranges 1E-11 hPa to 1E-15 hPa (C8 -18 alkyl sulfates) (...) Therefore, they decompose before reaching their theoretical boiling points". Thus, the obtained value should be considered an upper limit of the vapour pressure and accepted for the risk assessment calculations in the sense of a "worst-case scenario".