Measurement of exhaust gases

Exhaust gases are products of gaseous residues that result from a combustion process. They include carbon monoxide, monoxide and nitrogen dioxide, as well as fine particles that are carcinogenic.

If the exhaust gases cause environmental pollution (to which the majority of the population is exposed), there are occupations resulting in exposures that are much higher than that of the general population.


Main occupations exposed to exhaust gases:

  • Employees working in confined spaces (e.g.: users of diesel engines for underground work, drivers of diesel powered self-propelled trucks spending a notorious time inside warehouses);
  • Workers in charge of maintenance or technical inspection of motor vehicles;
  • Machine operators (e.g., construction sites, mining, agricultural tractors, trucks or light vehicles);
  • Personnel working near vehicles and equipment (e.g.: public roads, toll booths or parking lots);
  • Users of small gasoline engines (e.g., small generators, grinders, and chainsaws) exposed to exhaust gases that are particularly rich in carbon monoxide.

Adequate ventilation and EPI are required to protect against the risks associated with these gases.


Why is it essential to perform exhaust gas measurements?

The risk assessment shall identify work situations in which personnel are exposed to exhaust gases. Exposure conditions must be measured in order to allow the implementation of appropriate technical and organisational measures.

AVEC Ingénierie accompanies you in the audit and analysis of your problem through the realization of these measurements.

The results of the measurements are reported in detail in order to better understand the exposure of workers to these pollutants and to protect them by implementing corrective measures.

Les résultats des mesures font l’objet d’un rapport détaillé permettant de mieux connaître l’exposition des travailleurs à ces polluants et de les en prémunir par la mise en place de mesures correctives.

Measurement of dust

Dust measurements enable :

  • To measure dust concentration (inhalable and alveolar);
  • To measure filtration or dust removal efficiency;
  • To control dust collectors and ventilation monitoring systems.

And implement corrective actions if needed. AVEC Ingénierie supports you throughout these steps and helps you find effective and quick solutions to implement.


AVEC Ingénieurie, Category C Accreditation Holder

Category C accreditation (awarded by the Ministry of Labour) concerns premises with specific pollution (presence of inhalable and alveolar dust).

Inhalable dust enters the human body by respiratory means. Particles with a diameter greater than 5µm deposit predominantly in the nasopharyngeal region before being removed. Finer alveolar dusts reach the deepest areas of the lungs (the alveoli); they generally represent « 10 to 20% of the fraction of inhalable dusts ».

Therefore, exposure to alveolar dust (and inhalable in a smaller proportion) may cause lung overload. This acute or chronic mechanism is related to the limited ability to purify the lung.


What are the means of prevention and protection ?

In relation to the provisions of the Labour Code, we can mention

  • technical means (capture, filtration, misting);
  • organizational measures (monitoring and control: installation control system, camera);
  • behavioural practices and habits (regular implementation of training and information sessions on preventive and protective measures to be followed) to be implemented in the extractive industries.


How can dust hazards be controlled ?

For each of the Homogeneous Exposure Groups (HEGs) whose risk assessment concludes that they are “high risk”, the employer is expected to take at least one annual measure.


This measure meets the following conditions :

  • to be carried out at a fixed or mobile station (sampling equipment carried by the worker) in each of the specific pollution spaces that are characteristic of the HEG;
  • sampling time should be representative of the average daily activity in the local(s) with specific pollution;
  • sampling and analyses should be done either:
  • by a Category C accredited organization; or,
  • by an internal or external laboratory following a protocol recognized by the profession (e.g.: IMA-Europe Dust Monitoring Protocol); in this case, the degree of reliability of the results (uncertainty, etc.) is known.
  • updating the risk assessment in case of: changes in methods and/or operating conditions, changes in deposit/reservoir characteristics, new work station, new dust source machine, etc. (Recommendation R. 4412-5 and R. 4121-2).


The use of bodies approved by the Ministry of Labour is the result of regulations.

This recourse is not obligatory for all the periodic checks carried out in the undertakings; on the other hand, it will be prescribed in the case of checks carried out on demand by the labour inspectorate, or to verify compliance with the concentration limit values in the atmosphere of certain substances.

Periodic regulatory measures in construction ventilation

AVEC Ingénierie carries out the periodic ventilation regulatory measures imposed in Recommendation R.494 and, in the case of the Grand Paris Express, the CRAMIF DTE 266 (« Grand Paris – Underground works – Basis of minimum requirements for the prevention of occupational hazards »).


These services include :

  • Measurement of the air flow distribution over the entire site;
  • Measurement of fan operating point;
  • Measurement of air pressures and air temperatures;
  • Measurement analysis, air flow calculations;
  • Analysis of results, fan operation and ventilation record;
  • Provision of detailed measurement report with regulatory ventilation plan