NLS Certificate is an international pollution prevention certificate. Such certificates are mandatory for ships carrying noxious liquid substances (NLS) in bulk. The Coast Guard issues the endorsed Certificate of Inspection or NLS Certificate required by 46 CFR 98.31-10.
The following is an example of a federal regulation defining the term:
According to 33 CFR 151.05, NLS Certificate means an International Pollution Prevention Certificate for the Carriage of Noxious Liquid Substances in Bulk issued under MARPOL 73/78.