Overview
EN ISO 11079:2007 - Ergonomics of the thermal environment - provides standardized methods for the determination and interpretation of cold stress using the concept of required clothing insulation (IREQ) and for assessing local cooling effects (e.g., wind chill, extremity cooling). The standard applies to continuous, intermittent and occasional cold exposure for indoor and outdoor work. It is not intended for meteorological phenomena such as precipitation that are covered by other methods.
Key topics and technical requirements
- IREQ (Required Clothing Insulation): Calculation of the resultant clothing insulation needed to maintain body heat balance at defined physiological limits. IREQ is used as a primary indicator of general cold stress.
- General cooling assessment: A heat-balance approach that combines environmental parameters, clothing thermal properties and metabolic rate to determine thermal equilibrium and, where necessary, duration-limited exposures (Dlim).
- Local cooling assessment: Methods and criteria for assessing localized cooling due to convective (wind chill), conductive, extremity and airway cooling.
- Measurement and inputs: Use of standard instruments and inputs (air temperature, radiant temperature, air velocity, clothing insulation, metabolic rate) as referenced in normative documents.
- Annexed guidance: Includes computational procedures, physiological criteria, metabolic and clothing data, methods to determine wind cooling, sample evaluations and a computer program for IREQ calculations.
Referenced normative documents include ISO 7726, ISO 8996, ISO 9920, ISO 13731, ISO 13732-3, ISO 15831 and EN 511.
Practical applications and target users
- Occupational health & safety professionals: Evaluate worker cold stress, set safe exposure times, and select appropriate protective clothing.
- Ergonomists and human factors specialists: Integrate thermal ergonomics into task design and risk assessments.
- Protective clothing designers and manufacturers: Validate insulation performance and compare ensembles against required IREQ values.
- Workplace planners and field supervisors: Plan shifts, breaks and recovery times for outdoor or cold-environment operations (construction, offshore, cold storage, polar research).
- HVAC and building engineers: Assess indoor cold-work scenarios where localized cooling may be an issue.
- Researchers: Use standard methods for reproducible cold-stress studies and modelling.
Related standards
- ISO 7726 - Instruments for measuring thermal environment quantities
- ISO 8996 - Determination of metabolic rate
- ISO 9920 - Estimation of clothing thermal insulation
- ISO 13731 / ISO 13732-3 / ISO 15831 - Vocabulary, cold surface contact and thermal manikin methods
- EN 511 - Protective gloves against cold
EN ISO 11079:2007 is essential for anyone needing a consistent, scientifically based method to assess cold exposure risks, optimize clothing ensembles, and implement safe work practices in cold environments.
