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.

Homepage:
https://ctan.org/pkg/mhchem
