Decontamination in mass-casualty events

27 June 2022

An exploration into different methods for decontamination, especially when time is limited and the number of patients is large as in a mass-casualty event. Are we doing the right thing? Featuring Charles-Alexandre Campbell, Advanced Care Paramedic and CBRNE Instructor.

Nandamuri S, Feschuk AM, Maibach HI. A review of the efficacy of easily accessible dry decontaminants for human chemical contamination. Journal of Applied Toxicology. 2022 Mar 11.

Soap and water are often considered the gold standard for dermal decontamination. However, recent systematic reviews have shown that these methods often result in incomplete decontamination and may even induce contaminant absorption due to the “wash-in” effect. Therefore, it is important to gain insight on other decontamination methods. A literature search was done using PubMed to find experimental studies relating to dry decontamination performed with readily available items. Seven studies met eligibility criteria, and the study model, dry decontaminant, method of dry decontamination, method of analyzing decontamination, and main conclusions from each study were extracted, summarized, and compared. Important conclusions include that all studies investigated found that dry decontamination yielded decreases in contamination. In addition, it was shown by multiple studies that not only the decontaminant, but the manner in which it is used (method used [blotting, rubbing, etc.], amount used, and whether decontamination instructions are provided to exposed individuals) is vital to success. Finally, in all four studies that investigated wet and dry decontamination combination protocols, combinations were more efficacious than dry decontamination alone. However, this means that dry improvised decontamination can be performed while waiting for the deployment and arrival of further formal decontaminants. These conclusions deserve consideration in the event that universal decontamination guidelines are designed. However, more studies are required in order to draw definitive conclusions regarding the important topic of dermal decontamination.

James T, Izon-Cooper L, Collins S, Cole H, Marczylo T. The wash-in effect and its significance for mass casualty decontamination. Journal of Toxicology and Environmental Health, Part B. 2022 Apr 3;25(3):113-34.


Decontamination of skin by washing may increase dermal absorption, a phenomenon known as the wash-in effect. The wash-in effect is frequently discussed in studies investigating casualty decontamination where potentially life-saving interventions may enhance the dermal penetration of toxic chemicals, leading to an increase in incidence of morbidity and rates of mortality. However, the wash-in effect is seldom investigated within the context of mass casualty decontamination and real-life consequences are therefore poorly understood. This paper reviews the existing literature on the wash-in effect to highlight the proposed mechanisms for enhanced absorption and evaluate the wash-in effect within the context of mass casualty chemical decontamination.