Ventilation and Indoor Air Quality

Ventilation is the process of “changing” or replacing used air in any space to provide improved indoor air quality. Ventilation is employed in workplaces to control temperature, replenish oxygen, or remove moisture, odours, heat, dust, airborne bacteria, and carbon dioxide. It is also important to keep interior building air circulating, and to prevent stagnation of the interior air.

Ventilation of workplaces is required in terms of the Environmental Regulations for Workplaces, OHSAct (85 of 1993), employers must ensure that:

  • The air breathed is safe.
  • The time-weighted average of carbon monoxide does not exceed one half percent by volume air.
  • The time-weighted average of carbon dioxide does not exceed three percent by volume air.
  • The occupational exposure limit for substances is not exceeded.
  • The concentration of any explosive or flammable gas, vapour or dust does not exceed the lower explosive limit for that substance.

Where local exhaust ventilation (LEV) systems are used to control exposure to dusts, fumes, gases, mists and vapours hazardous to health, employers have a legal obligation to ensure that they continue to operate effectively.

Thorough examination and tests should be carried out at least once every 24 months to ensure the LEV equipment remains in good working order, as required in terms of Regulation 12 of the Regulations for Hazardous Chemical Substances, OHSAct (85 of 1993).

Indoor air quality in office buildings has also become a significant environmental issue. The number of
Indoor air quality complaints has increased in recent years with greater building tightness, the growing use of synthetic materials, and energy conservation measures that reduce the amount of outside air supply, resulting in an increase in indoor pollutants. The reactions to these pollutants have led to the phenomenon of sick building syndrome.

Adverse health effects due to poor indoor air quality may include:
Headaches, fatigue, respiratory irritation, nose bleeds, dry eyes, coughing and allergy symptoms.
All these negative effects contribute to poor productivity and absenteeism in the workplace.

We are an Approved Inspection Authority for the evaluation of ventilation and ventilation systems. OCSA conducts general ventilation and local extraction ventilation surveys to assist your business to comply with legal requirements, as well as perform indoor air quality surveys in occupied spaces, or investigate complaints of poor indoor air quality, to ensure conformance to recognised indoor air quality standards.

We will provide you with a report detailing our results, give reasons why areas did not conform to standards and provide practical solutions to correct the sub-standard extraction velocity or improve the ventilation and indoor air quality of the indoor environment.

OCSA can provide you with the following ventilation surveys:

  • General building ventilation surveys.
  • Indoor air quality surveys.
  • Sick Building Syndrome investigations.
  • Efficiency of laboratory fume cupboards, extraction ventilation systems and paint spray booths.
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