Excessive heat: what measures should be taken by the employer?

When it is very hot outside, this can cause discomfort in the workplace. To reduce the impact on the workers, the employer has the obligation to take certain measures.
A glance at what the Codex on well-being mentions on this subject.

What should the employer do in advance?

The employer must carry out a preliminary risk assessment of the thermal environment factors which are present in the workplace, taking into account the following factors:

• the air temperature, expressed in degrees Celsius;
• the relative humidity of the air, expressed in percentage;
• the speed of the air movement, expressed in meters per second;
• the thermal radiation from the sun or technological conditions;
• the physical workload, assessed by the energy to be produced per second, necessary to perform a task and calculated in watts;
• the working methods and work equipment used;
• the characteristics of the work clothing and personal protective equipment;
• the combination of all these factors.

When should the employer take measures?

The employer must take certain measures when the action values for heat exposure are exceeded. These action values for heat exposure, determined on the basis of the WBGT index based on the physical workload, are the following:

• 29 for very light or light work;
• 26 for medium work;
• 22 for heavy work;
• 18 for very heavy work.

The value of the WBGT index can either be measured directly or be calculated by reference to the measurement of the climatic parameters of the air temperature, the humidity of the air, the speed of the air movement and the thermal radiation (for more information on the WBGT-index: http://www.emploi.belgique.be section 'Bien-être au travail/Facteurs d’environnement et agents physiques/Ambiances thermiques').

What measures should be taken?

When the above values are exceeded on a climatological level, the employer must take a number of measures. He/She must:

• make collective or personal protective equipment available to the workers who are exposed to direct solar radiation;
• take the required measures to ensure the distribution of appropriate refreshing beverages, free of charge for the workers, in accordance with the advice given in this regard by the prevention adviser-occupational physician;
• install artificial ventilation devices on the work premises within a period of 48 hours from when the nuisance is established.

If the nuisance continues after this period despite the measures taken, the employer has to establish a working regime that alternates remaining at the work station with rest periods.

Should you require more information, please do not hesitate to contact your external service for prevention and protection at work.

Source: Codex on well-being, Title IV, chapter 2.

Author: Catherine Legardien

02/07/2018