INDOOR AIR QUALITY TESTING & ASSESSMENT
Indoor air quality testing shows employers whether the air in their offices and enclosed workplaces meets the legal guideline levels. Testing is needed wherever indoor air quality may fall outside those levels, which are set in Table 3 of the Physical Agents Regulations, 2024. It is also the sensible first step when staff complain about stuffiness, temperature, draughts or odours.
We measure the five Table 3 parameters: air temperature, air velocity, relative humidity, carbon dioxide and carbon monoxide. Because the carbon dioxide level is set relative to outdoor air, we also take an outdoor reference reading. That reading is only a reference: we do not offer environmental monitoring. We then look at ventilation, air distribution and likely sources, so the report tells you what to fix first.
WHY POOR INDOOR AIR QUALITY IS A RISK
Poor indoor air causes headaches, dizziness and fatigue, irritates the eyes, nose and throat, and can bring on respiratory discomfort and allergic reactions. When symptoms are linked to the building rather than a specific illness, this is known as sick building syndrome.
Complaints often trace back to too little outside air, poor air distribution, dirty filters, damp and mould, or chemicals from cleaning and printing. Fuel-powered forklifts, generators or gas heaters running indoors add carbon monoxide. For the business, the cost shows up as lower concentration and productivity, more absenteeism and weaker morale.
Indoor air quality is regulated by the Occupational Health and Safety Act, 1993 (OHS Act) and the Physical Agents Regulations, 2024. The assessment and testing duties are:
• Risk assessment (regulation 6): a competent person must assess exposure to physical agents before employees are exposed, then at least every 24 months. It covers indoor air quality along with heat, cold, lighting, vibration and non-ionising radiation.
• Indoor air quality survey (regulations 7 and 12): by a competent person where the risk assessment shows indoor air may fall outside the Table 3 levels, at the frequency it sets and at least every 24 months.
• Mechanical ventilation (regulation 12(3)(b)): artificial ventilation systems must be tested by a competent person at the manufacturer's intervals, and at least every 24 months.
Review your overall occupational health risk assessment (OHS Act, section 8(2)(d)) together with these assessments. The regulations do not require an approved inspection authority (AIA) for any of this work.
WHAT THE LAW REQUIRES FOR INDOOR AIR
HOW WE TEST INDOOR AIR QUALITY
Christo de Wet leads every indoor air quality survey from planning to report. He is an occupational hygienist registered with the Southern African Institute for Occupational Hygiene (SAIOH), ROH 0953, with 15 years of experience.
Before the visit, we ask for a floor plan, details of the air-conditioning and ventilation systems, and where and when staff complain. We plan the survey for a normal working day with normal occupancy.
On the day, we measure the five Table 3 parameters in each area with calibrated instruments. We walk the building with you, looking at ventilation, air distribution and likely sources such as blocked diffusers, damp, and engines or gas heaters running indoors. We assess ventilation against SANS 10400-O.
After the visit, we compare the results with the Table 3 guideline levels. Table 3 states no averaging period, so the report explains how readings were taken and compared. Where a process releases dust or fumes, the report notes that local extraction at the source usually controls it better than general ventilation. Lighting can be surveyed on the same visit.
- • Results for each area against the five Table 3 guideline levels
• An outdoor carbon dioxide reference, since that guideline is set relative to outdoor air
• An explanation of how readings were taken and compared
• Findings on ventilation, assessed against SANS 10400-O, and on air distribution
• Likely chemical or biological contributors seen on the walk-through, such as visible mould
• Practical recommendations, in order of priority
• A report written for management, SHEQ teams and auditors
What affects the quote: the size of the building and the number of areas to cover, which set the time on site, and travel to site. Quotations list each service as its own line item, so a lighting survey on the same visit appears as a separate line.
WHAT YOUR AIR QUALITY REPORT INCLUDES
- How often must indoor air quality be tested?
Testing is needed when the physical agent risk assessment shows indoor air may fall outside the Table 3 guideline levels. It must then be done at the frequency the risk assessment sets, and at least every 24 months. Artificial ventilation systems must also be tested at the manufacturer's intervals, and at least every 24 months.
What are the indoor air quality guideline levels?
Table 3 of the Physical Agents Regulations, 2024 sets air temperature at 20 to 28 °C (dry-bulb). Air velocity should be 0,1 to 0,5 m/s and relative humidity 30 to 60 %. Carbon dioxide should not exceed the outdoor concentration by more than 600 ppm, and the carbon monoxide guideline is 10 ppm. Monitoring must also take mould and other chemical and biological agents into account (regulation 12(4)).
Who may do indoor air quality testing?
It must be a competent person, with the knowledge, training, experience and relevant qualifications for the physical agent. Instruments must be calibrated to a traceable standard. The regulations do not require an approved inspection authority (AIA). Christo de Wet, SAIOH ROH 0953, leads every Qualitas survey.
What must we prepare?
A floor plan, air-conditioning and ventilation details, the manufacturer's maintenance specifications if you have them, and normal occupancy on the day. Our free online Compliance Gap Assessment shows whether your risk assessment and ventilation tests are due.
FREQUENTLY ASKED QUESTIONS
Free online tool: Compliance Gap Assessment. See what is due at your workplace
Occupational hygiene for hospitals, clinics and laboratories
Occupational hygiene for warehousing, logistics and distribution
Indoor air quality: what must be tested, and how often?
What must a physical agent risk assessment cover?
What do the Physical Agents Regulations, 2024 require?
What is an AIA inspection in South Africa, and which AIA do you need?
FREE TOOL AND ARTICLES
REQUEST A QUOTE
Request a quotation for indoor air quality testing below, with your site address and the areas to cover. We work in all nine provinces, travel is quoted upfront, and lighting can be surveyed on the same visit.
