4.1 The methanol wall wash practice is performed to determine the cleanliness and suitability of cargo tanks or compartments on a marine vessel prior to loading polyester grade monoethylene glycol. Polyester grade monoethylene glycol has very high quality requirements and must be handled with care, as it is adversely affected by oxygen, hydrocarbons, water, and chloride. It is especially susceptible to aromatic contamination, which degrades UV transmittance. Possible sources of contamination are the prior cargoes and cleaning agents. The methanol wall wash procedure provides a representative sampling of the impurities and contamination present on the sides of the cargo tank.

1.1 This practice covers the methanol wall wash procedure for cargo tanks of marine vessels handling polyester grade monoethylene glycol.

1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see Section 7.

1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.