International requirements for the prevention of pollution from chemical tankers are contained in Annex II of the International Maritime Organization's Pollution Convention entitled Regulations for the Control of Pollution by Noxious Liquid Substances in Bulk. Annex II contains requirements applicable to ships carrying noxious liquid substances (NLS) in bulk. These requirements deal with categorizing NLS; discharging of NLS residues or mixtures; pumping, piping and unloading arrangements; reception facilities; unloading procedures, including efficient stripping and tank washing; cargo record book; surveys; International Pollution Prevention Certificate for the Carriage of Noxious Liquid Substances in Bulk; compliance with the International Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in Bulk (IBC Code) or the Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in Bulk (BCH Code) by chemical tankers; carrying and discharging oil-like NLS; procedures and arrangements manuals; and shipboard marine pollution emergency plans.
The international provisions in Annex II of the Pollution Convention have been incorporated into Canadian legislation in Division 2 – Noxious Liquid Substances and Dangerous Chemicals – of the Regulations for the Prevention of Pollution from Ships and for Dangerous Chemicals. These regulations apply the Annex II discharge provisions in Canadian coastal waters; however, stricter discharge provisions are applied in Canadian internal waters. The regulations also incorporate the provisions of the IBC Code or the BCH Code for those ships that carry dangerous chemicals that are not necessarily noxious liquid substances.
Ships may integrate their shipboard oil pollution emergency plan with the shipboard marine pollution emergency plan for noxious liquid substances.