Demonstrating that the air quality at work makes you sick, quite a challenge

Demonstrate that the air quality at work makes you sick, a whole challenge


Over the past year, we have heard a lot about health problems related to air quality in public buildings, especially in schools.

< p>Recently, the Administrative Labor Tribunal rendered an important decision on this subject.

In this case, workers believed they had suffered from diseases related to the sphere of ENT (otolaryngology) resulting from the poor air quality in the establishment where they worked. These were problems of rhinitis, colds, nasal congestion, recurrent flu, etc. 

The workers concerned claimed more specifically that the illnesses from which they suffered stemmed from the presence of mold in the workplace, particularly caused by various episodes of water leaks, thus contaminating the ambient air.

Several Factors

On this occasion, the Administrative Labor Tribunal recalls that molds are microscopic organisms comprising thousands of species and present everywhere in nature, both inside and outside buildings. The court also points out that various factors must be present to ensure that mold can proliferate and produce spores harmful to health and circulating in the ambient air. These factors which are necessary to be present are:

  • sufficient amount of water, whether damp or wet elements or relative humidity of the room. air equal to or greater than 65%;
  • nutrient elements, that is to say which, mixed with water, will allow the development of molds, such as wood, gypsum boards, etc. ;
  • an appropriate temperature, i.e. comparable to that existing inside buildings and therefore excluding excessively cold conditions.

The court will also consider that it must take into account all the factors and that elements such as a foul or rotting odor, the presence of mold around toilets, windows or ceilings are not necessarily proof that there is contamination of the environment .

In short, for there to be a contamination dangerous to health in a fungal environment, there must be an uncontrolled proliferation of molds, regardless of where this proliferation exists. In the case that concerns us, the workers, in addition to the health problems they allegedly suffered, considered that these problems were less when they were not at work.

Despite the presence of certain elements such as bad odors or dust that could possibly, with water leaks, lead to the presence of mold at levels harmful to health, the court considered that the elements were not met. to enable workers' compensation.

Scientific demonstration

In fact, although it is now accepted that most species of molds and mycotoxins can cause health problems related to the ENT sphere, such as conjunctivitis, nasal congestion, recurrent flu, etc., it must necessarily be demonstrated, by scientific proof, that these molds or mycotoxins are present in a relatively significant way in the ambient air in the workplaces.

Most of the time, these are studies carried out by experts in the field, such as industrial hygienists in the workplace, who will be able to demonstrate that we are in the presence of uncontrolled proliferation of molds, the very ones that will cause health problems. < /p>

Complex and sometimes expensive

We should also mention that while our senses, such as smell, can be useful in identifying mold, they can also be misleading. For example, CO2 is odorless and colorless, yet above a certain level it can be deadly.

Ultimately, demonstrating uncontrolled mold growth is an exercise often very complex and sometimes involves significant costs.

Bernard Cliche, lawyer emeritus at Morency Société d'avocats