Proceedings of the Public Security S&T Summer Symposium 2009

CRTI 06-0319TD

Guidelines for Combined Air Demand and Heat Strain Management of First Responders

Project Lead: Canadian Police Research Centre

Federal Partner: DRDC Toronto

Industry Partner: Moroz Biomeasurement Systems Inc.

Other Partners: University of Waterloo, Loughborough University, Toronto Fire Service, Toronto Police Service, Royal Canadian Mounted Police – Toronto Detachment, Canadian Joint Incident Response Unit

Objectives

Incident commanders need to be able to assess the potential risks of the environment to their personnel in order to define the level of personal protective equipment (PPE) required to handle the incident. However, once the level of protection is defined, commanders also need to understand and safely plan for the potential life-threatening and functional limitations of the PPE on the first responder. Currently, guidelines are not available that define safe exposure durations for first responders functioning in Level A or B ensembles. This project will develop standards and guidelines that will assist incident commanders in ensuring that their personnel are safe and not at risk of becoming a casualty due to heat injury from an excessive rise in core temperature while wearing their PPE or asphyxiation due to exhausted air supply from their self-contained breathing apparatus (SCBA).

Relevance

Protective clothing and SCBA are designed to allow the first responder to function in a contaminated environment; however, the risk assessment must also consider the potential for heat injury (e.g., heat exhaustion and heat stroke) and asphyxiation with the use of PPE and SCBA. Presently no laboratory- and field-validated standards exist that safely manage these two factors, which limit the duration of PPE functionality for first responders. The outcomes from this project, therefore, will enable CRTI to establish safe work standards. By establishing these safe-exposure-time guidelines, incident commanders can focus on carrying out hazard identification and forensic evidence gathering without concerns for placing their personnel at increased risk of heat injury or asphyxiation with the use of the required protective clothing and equipment.

Recent Progress and Results

The project, which has just begun, will be carried out over the next three years. Management of thermal strain and options for cooling will be investigated in the climatic facilities at DRDC Toronto. Loughborough University in the United kingdom (UK) will determine the intrinsic clothing insulation and water vapour permeability of the ensembles at different wind speeds using an articulating thermal mannequin. The University of Waterloo will lead the air management component of the project by providing real-time measurements of metabolic rates and air demand of activities conducted in the Level A and B ensembles. In addition, the University of Waterloo will assist with the validation of heat-strain models and clothing-adjustment factors that will ultimately allow work guidelines to be constructed for different environmental conditions, clothing configurations, and metabolic rates. The final product, after field confirmation with end-users, will provide incident commanders with an electronic tool to determine time limit guidelines that ensure safe management of air supply and heat stress for levels of PPE requiring the use of SCBA.

Impact

Incident commanders must deal with the uncertainty of the hazards within the environment in which they ask their personnel to gather forensic samples and conduct criminal investigations. These initial uncertainties require the use of PPE that are impermeable to the transfer of environmental contaminants and require that a clean and safe air supply is provided through the use of SCBA. The requirement for this protection, however, places the first responder at risk of death from heat injury because of the restriction of heat transfer from the body through the clothing, and asphyxiation if proper work and rest guidelines are not followed. The outcome from this project will be an electronic tool that allows incident commanders to prescribe appropriate work and rest strategies to safely manage the risk of heat injury and asphyxiation. By ensuring the safety of their personnel, the incident commander can then focus on the requirements of the scenario for criminal investigation and gathering of forensic evidence.

Authors

Tom M. McLellan, DRDC, tom.mclellan@drdc-rddc.gc.ca

Richard L. Hughson, University of Waterloo, hughson@healthy.uwaterloo.ca

Beth J. Weckman, University of Waterloo, ejweckman@uwaterloo.ca

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