The Approved Code of Practice 1990 requires employers to provide sterile saline 0.9% or sterile water for eye irrigation where mains tap water is not readily available. This should be in sealed containers of at least 300mL and should not be re-used once open.
Sterile eye wash contains 0.9% w/v sterile sodium chloride solution with a twist cap to break seal. Single use only, not to be re-sealed or re-used.