The effects of chemical protective suits on human performance Susan L. Murray * , Yvette L. Simon, Hong Sheng Missouri University of Science & Technology, 600 West 14th Street, EMgt Bldg, Rolla, MO 65409, USA article info Article history: Received 15 March 2011 Received in revised form 1 June 2011 Accepted 2 June 2011 Keywords: Protective clothing PPE Level A chemical suit Human performance abstract Workers in the chemical industry are often required to wear protective suits while performing tasks. While these suits can be life saving, they increase the difficulty and discomfort faced by the wearer. This research explores the performance of individuals wearing the highly cumbersome Level A suit. The suits are heat-retentive and can cause fatigue that affects performance by increasing response time and decreasing accuracy. Members of Missouri’s Civil Support Team (CST) served as subjects for this research. They conducted fine and gross motor tests. Their completion time and accuracy were evaluated both out- of-suit and in-suit for the Level A chemical protective suits. A t-test was conducted to evaluate the effect of the Level A suits on performance. Results showed a significant increase in completion time and errors for gross motor tasks. This type of task had up to a 103% increase in time required and up to a 34% decrease in accuracy. The suit’s impact on fine motor skill was also significant, but to a lesser extent. Repeated measures test was performed to evaluate any potential time-in-suit effect. A decrease in mean task completion time was observed for some of the tasks. There was a corresponding decrease in accuracy but no consistent time-in-suit effect was identified. The results indicate the need for care when designing procedures and equipement to be used by humans wearing restrictive PPE. It is important to take human limitations into consideration in the design phase in order to decrease the need for human adaptation and increase system safety. To achieve this, understanding human factors is imperative when designing equipment, tasks, or procedures for workers wearing PPE. Ó 2011 Elsevier Ltd. All rights reserved. 1. Background Several events over the past decade have led to an increased awareness of the importance of effective crisis response. As General Pershing said in 1919, shortly after the First World War, “.but the effect is so deadly to the unprepared that we can never afford to neglect the question.” Between then and now countless crisis situations requiring complex responses have arisen, ranging from natural disasters like hurricane Katrina to deadly man-made ones such as anthrax terrorist attacks. First response teams, chemical workers, fire fighters, and hazardous materials (HAZMAT) personnel are often called on to lead responses in such situations. When threats involving unknown or potentially dangerous substances arise, response teams must wear substantially insus- ceptible personal protective equipment (PPE). Protective clothing can negatively impact the users’ perfor- mance in several ways including increasing heat stress on the body, reducing task efficiency, and reducing the individual’s range of motion (Adams, Slocum, & Keyserling, 1994). In most chemical, biological, radiological, or nuclear (CBRN) scenarios, first responders wear multiple layers of gloves, elaborate hooded suits, and breathing apparatuses. These can cause severe detrimental effects on performance due to restricted peripheral vision and limited motor dexterity. Task completion tends to become expo- nentially more difficult in terms of time and effort (Gertman, Bruemmer, & Hartley, 2007). While these detrimental effects caused by PPE have been established, it is important to quantify their impact on worker performance, and thereby understand the implications of these when it comes to designing for use in the suit. Level A suits are maximum protection chemical suits worn by trained individuals when dealing with unknown substances threats. Due to the degree of protection provided, these suits tend to be bulky and highly heat retentive. According to OSHA regula- tions, Level A suits are to be selected “when the greatest level of skin, respiratory, and eye protection is required” (Occupational Safety and Health Standards, Standard Number 1910.120 App B, 1994). It typically includes a fully encapsulating chemical- resistant suit, gloves and boots, and a pressure-demand, * Corresponding author. Tel.: þ1 573 341 4038; fax: þ1 573 341 6567. E-mail address: murray@mst.edu (S.L. Murray). Contents lists available at ScienceDirect Journal of Loss Prevention in the Process Industries journal homepage: www.elsevier.com/locate/jlp 0950-4230/$ e see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.jlp.2011.06.001 Journal of Loss Prevention in the Process Industries 24 (2011) 774e779