Service area: Available in California, Nevada, Arizona, Oregon, Washington, Idaho, Montana, Utah, Wyoming, Colorado, New Mexico, North Dakota and South Dakota.
There is no OSHA standard for indoor air quality, and that is precisely why these complaints go unresolved for months. An employee reports headaches, irritated eyes, a smell nobody can place. There is no permissible exposure limit to compare against, so the building manager changes a filter and the complaints continue. IAQ is an investigation problem, not a compliance checkbox, and it is solved with measurement and method.
What actually gets measured
- Carbon dioxide as an indicator of outside-air delivery and occupant loading — the single most useful first reading in an office complaint.
- Carbon monoxide, where combustion equipment, loading docks or parking structures are anywhere near an intake.
- Temperature and relative humidity, which explain a surprising share of complaints on their own and drive microbial growth above roughly 60 percent RH.
- Volatile organic compounds from new furnishings, adhesives, flooring, cleaning products and adjacent operations.
- Particulates, including the fine fraction that carries wildfire smoke into a building.
- Bioaerosols and visible microbial growth, with moisture mapping to find the source rather than the symptom.
- Ventilation performance itself — outside-air fraction, supply and return balance, filtration in place versus filtration specified, and whether the system is doing what its design says.
The comparison points come from ASHRAE guidance, from 8 CCR §5142 where the building has a mechanical HVAC system, and, where a specific contaminant is identified, from its own permissible exposure limit under 8 CCR §5155. Where the source is a process rather than the building — a spray booth, a bench, a mixing operation — the governing rule is 8 CCR §5143, which requires exhaust systems to be designed, maintained and operated so as to prevent harmful exposure, with enough volume and velocity to capture and dispose of the dusts, fumes, mists, vapors and gases at the point they are produced.
Wildfire smoke is a California IAQ problem with its own standard
California does have an enforceable rule where wildfire smoke is concerned: 8 CCR §5141.1, which is triggered by an AQI for PM2.5 of 151 or greater and reaches employers whose workers are exposed. Buildings pull that smoke in through their intakes, and the indoor consequences persist after the outdoor AQI recovers. Post-fire assessment of a building interior — smoke, soot, char and odour — is a distinct discipline covered under post-wildfire property assessment.
The §5142 obligation almost nobody is meeting
If your building runs a mechanical HVAC system, 8 CCR §5142 requires more than switching it on. Outdoor air must be delivered in accordance with the California Building Standards Code, the system must run continuously during working hours apart from narrow exceptions, and the employer must inspect the system annually, document the maintenance and keep those records for at least five years. In practice the records are the first thing an inspector asks for after an IAQ complaint, and they are very often the thing that does not exist.
What we do
- Indoor air quality investigation in response to occupant complaints
- CO₂, CO, temperature and relative humidity profiling across a working day
- VOC and particulate sampling, including PM2.5
- Bioaerosol sampling, moisture mapping and microbial source identification
- Ventilation performance assessment — outside-air fraction, balance and filtration
- §5142 documentation review and corrective recommendations
- Wildfire smoke exposure assessment and §5141.1 program development
- Post-fire and post-water-damage interior assessment
- Written reports suitable for building owners, tenants, counsel and insurers
- Expert testimony in habitability and building-related illness matters — see litigation support
Frequently asked questions
Is there an OSHA standard for indoor air quality?
There is no general IAQ standard with numerical limits for an office. That is why these complaints stall. What does apply: 8 CCR §5142 for buildings with mechanical HVAC, §5143 for local exhaust where a process is the source, §5155 permissible exposure limits once a specific contaminant is identified, §5141.1 for wildfire smoke, and the general Injury and Illness Prevention Program duty at §3203 to identify and correct workplace hazards.
What does a carbon dioxide reading actually tell you?
It is not usually a toxic exposure question at office concentrations. CO₂ is a proxy for how much outside air is reaching the occupied space relative to how many people are in it. A steadily climbing reading through the working day points to under-ventilation or a system not delivering its design outside-air fraction, and that single measurement often explains complaints that had been attributed to something exotic.
We had a mold complaint. Do you do mold testing?
We do moisture mapping, visible-growth assessment and bioaerosol sampling, and we look for the water source. Air sampling for spores on its own is frequently over-sold and under-interpreted — a number with no source found and no moisture control changes nothing. The deliverable that matters is the identified intrusion path and the corrective work that stops it.
Can this be used in a habitability or building-illness case?
Yes. The sampling is documented to a standard that holds up in an appeal or a courtroom, and expert reports, deposition and trial testimony are available. See property health and safety assessment and expert witness and litigation support.
Talk to Michael directly
Call (626) 546-9384 or email mike@mcneilsafetyconsulting.com. See also industrial hygiene and the full list of services.
States We Serve
McNeil Safety Consulting provides this service to clients in the following states:
- California
- Nevada
- Arizona
- Oregon
- Washington
- Idaho
- Montana
- Utah
- Wyoming
- Colorado
- New Mexico
- North Dakota
- South Dakota
To confirm coverage for your site, call (626) 546-9384.