This part of ISO 15749 is valid, in conjunction with ISO 15749-2 to ISO 15749-4, for planning and designing drainage systems which evacuate wastewater from accommodation and commissary areas (sanitary drainage) on ships and marine structures. Drainage of weather decks, cargo holds and swimming pools is covered by ISO 15749-5. This series of standards takes into consideration the basic regulations and minimum requirements concerning hygienic requirements and the protection of the marine environment. This part of ISO 15749 does not apply to pipe systems carrying oily, chemically contaminated wastewater capable of forming flammable gas/oxygen mixtures.