The bundle provides three packages:

The mhchem package provides commands for typesetting chemical molecular formulae and equations.

The hpstatement package provides commands for the official hazard statements and precautionary statements (H and P statements) that are used to label chemicals.

The rsphrase package provides commands for the official Risk and Safety (R and S) Phrases that are used to label chemicals.

The package requires the expl3 bundle.

See also r-und-s.

The author is Martin Hensel. The package is Copyright © 2004-2014 Martin Hensel.