HM 69. Procedures for determining H2S concentration in cargo tank head spaces

Overview:

This document provides information and procedures with which to safely measure H₂S in the vapour space of a cargo tank. These procedures apply to ships and barges (all referred to as 'ships') and may also be used for determining the H₂S level above oil cargoes in fixed roof storage tanks providing that a vapour lock valve is installed on top of the tank.

This document is a summary of good practice used within the industry when handling cargoes where H₂S might be present and should be used in conjunction with any applicable regulations or specific guidelines provided by the terminal, ship or cargo owner, which will take precedence.

The document is for use primarily by terminal operators, cargo inspectors and ship’s staff that need to operate safely near to measurement and sampling points, cargo tank hatches and other openings into cargo tanks.