Haemorrhage remains to be a leading cause of death for trauma victims (Bellamy, 1984). Wound contamination poses an additional complication in the initial management of haemorrhaging wounds, with no specific medical treatment at present. Therefore, a requirement exists to develop haemostatic products that, when applied to wounds, can simultaneously arrest haemorrhage and negate any toxic effects of contaminants. The aim of this study was to assess the effect of chemical warfare agents (CWA; sulphur mustard; HD and VX) on the clotting efficiency of seven, commercial-off-the-shelf haemostats using an in vitro system (thrombelastography; TEG). Serial samples of citrated, whole blood were acquired daily from six large white pigs. After a 30 min stabilisation period, aliquots were analysed by TEG either in the absence of a treatment (control) or following the addition of a haemostat (0.45% w/v) and/or CWA (0.5 μl ml−1). For brevity, only “R time” results (indicative of time to initial fibrin clot formation) are presented (Fig. 1). Statistics were performed using a parametric ANOVA with Tukey post-test (predetermined α level of 0.05).