Decontamination of NBC-protective garments - part 5: Thermal decontamination of the protective suit NM 143

Abstract

Thermal decontamination of the NBC-protective suit (NM143) has been studied. The NM143 overgarment consists of a liquid repellant outer layer and an inner layer of activated charcoal fixed on polyurethane foam. Small pieces of fabric were exposed to 10 g/m2 sulphur mustard (HD) and decontaminated in a tube oven at temperatures from 80 to 150 °C for 1,4 and 24 hours, respectively. The airflow was kept constant at 2 l/min in all experiments. These small-scale laboratory experiments show that decontamination with respect to HD can be obtained using temperatures from 80 to 150 °C and heating for 1 hour. Heat-treatment for 4 and 24 hours also gave satisfactory results at the lower temperatures 80 and 100 °C. Introducing humidity in the airflow at 100 °C gave significantly better protection against HD after decontamination than for decontamination in dry air. This effect was not observed at 130 °C. Decontamination by heat-treatment was compared with the recommended laundering procedure from previous studies. This was heat-treatment for 4 hours at 100 °C in humid air (airflow 2 l/min) and laundering at 60 °C for 45 min, and subsequent rinsing three times in cold water. Experiments performed the same day on the samples taken from the same NM143 suit showed that both procedures gave satisfactory decontamination.