PERSONAL SAFETY DURING GAUGING AND SAMPLING OPERATIONS Published: 14 July 2026 Gauging and sampling of liquid cargoes are routine shipboard operations, but they can also expose crew and surveyors to significant personal safety risks if not properly managed. While these tasks may at times appear straightforward or repetitive, incidents continue to occur across the industry involving toxic vapour exposure, oxygen deficiency, chemical burns, fires and even fatalities. Many liquid cargoes carried today – including petroleum products, chemicals, biofuels and cargo blends – may present hazards that are not immediately obvious from appearance or smell alone. Even relatively common cargoes may release dangerous vapours, particularly when tanks are opened for manual gauging or sampling. For this reason, gauging and sampling activities should never be treated as a routine “exercise but rather approached with the same level of caution and planning as any other potentially hazardous tank operation. Understand the cargo hazards Before commencing any operation, the crew should ensure that they are familiar with the cargo being handled and its associated hazards. Safety Data Sheets (SDS), cargo information and vessel procedures should be reviewed in advance. Particular attention should be paid to: Toxic vapour risks (e.g. benzene, hydrogen sulphide) Flammability and ignition risks Oxygen depletion potential Corrosive or irritant properties Static accumulation risks Vapour pressure and expected tank atmosphere In some cases, the risks may not originate solely from the nominated cargo itself. Contamination, blending products, additives, residues from previous cargoes, or tank cleaning chemicals may also introduce additional hazards. Minimise exposure to vapours One of the most significant risks during gauging and sampling operations is exposure to vapours released when opening tank hatches or vapour locks. The crew should avoid positioning themselves directly over tank openings. Vap