Professional Study of Tank Cleaning Procedures and Compliance in Nigerian Product Tanker Operations

Tank cleaning is a technically demanding and environmentally sensitive operation essential to the safe loading of different petroleum products in tanker operations. This study examines tank cleaning procedures and regulatory compliance practices among product tankers operating between Nigerian petroleum product terminals. A professional practice review methodology was employed, using structured interviews with twenty tanker officers and chemical specialists, review of tank cleaning records and cargo compatibility matrices from ten product tankers, and assessment of port reception facility availability for tank washing residues at major terminals. The study benchmarks findings against MARPOL Annex II requirements and International Safety Guide for Chemical Tankers standards. Findings indicate that water washing with hot water is the dominant tank cleaning method, with chemical cleaning agents used for residue-specific cleaning of molasses and palm oil cargoes. Compliance with the requirement to discharge tank washing residues only to approved port reception facilities is inconsistent, with several operators admitting to offshore discharge when reception facilities are unavailable or overpriced. Documentation of tank cleaning operations in the cargo record book is found to be incomplete on a proportion of sampled vessels. Recommendations include mandatory cargo record book audit at each port of call, investment in adequate port reception facilities at all major product terminals, and industry development of a standardised tank cleaning planning tool for Nigerian product trades. Keywords: tank cleaning, product tanker, MARPOL Annex II, cargo record book, port reception facilities