Decontamination of NBC-protective garments - part 3: laundering of NM143 suits and effect of storage conditions

The NM143 NBC-protective suit used by the Norwegian armed forces has been examined with respect to the feasibility of decontamination by laundering, effect of storage conditions and lifetime. Protective properties were established by penetration analyses using liquid sulphur mustard (HD) corresponding to a contamination level of 10 g /m². The laundering experiments showed that the suits can be laundered at 40 or 60 °C, but the suit does not stand more than one laundering. The suits can not be laundered at 90°C. It is concluded that the suits can be decontaminated once by laundering at 60 °C with a selected detergent. For cleaning dirty suits a washing temperature of 40 °C is sufficient. The effect of storage conditions was examined on four different suits over a period of 17 months. All suits showed a significant variation in protective properties which could be correlated to variations in relative humidity (RH) due to seasonal changes. Further tests have to be performed under controlled conditions in order to validate this theory. Examinations of the protective properties of 12 suits after 10-13 years of storage show that the suits still meet the protection requirement against chemical warfare agents. As compared to an investigation in 1997 the protective properties have decreased. Hence, it is important to continue to do regular tests of the protective properties of NM143 garments.