The stronger, the better? A natural experiment on the effects of pepper spray concentration levels

Abstract

PurposeOleoresin capsicum (OC) spray has proven to be a relatively effective tool to subdue resistant or aggressive subjects without causing major and permanent injuries. Several products are available to law enforcement organizations and sprays with higher concentrations are sold as more effective, despite the lack of empirical evidence. This article aims to test the proposition that more concentrated OC sprays are more effective in a policing context.Design/methodology/approachTo test this proposition, retrospective data on police interventions that had occurred (N = 1,019) were used. Concentrations were divided in three levels: level 1 sprays (containing up to 0.49% of major capsaicinoids), level 2 sprays (from 0.5% to 0.99%) and level 3 sprays (between 1 and 1.33%). Propensity scores were calculated to estimate the average effect of concentration level on effectiveness, while controlling for confounding factors.FindingsLevel 1 and level 2 sprays were found to be similar in terms of effectiveness, but level 3 sprays were found to be more likely to have an immediate effect but were also related to higher chances that decontamination was needed after use.Originality/valueWhile several studies of the effectiveness of OC spray in general have been conducted in the past, this is one of the few to differentiate types of OC sprays according to their concentration level. As such, it aims to provide guidance to police organizations who must choose among a variety of products.