This International Standard gives specifications for natural rubber latex concentrate which has been concentrated by evaporation. It does not apply to natural rubber latex concentrates which have been concentrated by centrifuging or creaming, or to latices from natural sources other than Hevea brasiliensis, or to compounded latex or vulcanized latex. This International Standard covers requirements for evaporated natural rubber latex concentrates of the following types: NR latex, type HA evaporated: Evaporated latex concentrate preserved with ammonia only or with ammonia together with other preservative(s), with an alkalinity of at least 0,60 % (m/m) with respect to the latex. NR latex, type KHS evaporated: Evaporated latex concentrate preserved with potassium hydroxide and having a nominal total solids content of 73 % (m/m). NR latex, type KLS evaporated: Evaporated latex concentrate preserved with potassium hydroxide and having a nominal total solids content of 68 % (m/m).