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Indoor air quality problems can be caused by ventilation system deficiencies, overcrowding, tobacco smoke, microbiological contamination, outside air pollutants, and off gassing from materials in the office and mechanical equipment. Related problems also may include comfort problems due to improper temperature and relative humidity conditions, poor lighting, and noise levels, as well as adverse ergonomic conditions, and job-related stressors.
The National Institute for Occupational Safety and Health (NIOSH) also uses the term Indoor Environmental Quality.
Scope
Affects individuals who may be exposed to indoor air contaminants. Indoor air quality problems encompasses complaints from one or two employees to events where entire facilities are shut down and evacuated until the situation is investigated and problems corrected.
The Environmental Protection Agency does not regulate indoor air quality, and OSHA only covers specific areas. Although OSHA does not have indoor air quality standards, it does have standards about ventilation and standards on some of the air contaminants that can be involved in indoor air quality problems.
In addition, many states have guidance on indoor air quality. Check your state health department website. These include California, Maryland, New Jersey, and New York.
Regulatory citations
- 29 CFR 1910.94 — Ventilation
- 29 USC 654 — Duties of employers and employees (including Pub. L. 91–596 “OSH Act of 1970” 5(a)(1), the “General Duty Clause”)
The General Duty Clause of the OSH Act requires employers to provide safe and healthful workplaces for their employees. If a situation involving mold contamination presents a serious hazard, OSHA could use the General Duty Clause to cite employers.
Key definitions
- Clean air: Air of such purity that it will not cause harm or discomfort to an individual if it is inhaled for extended periods of time.
- Exhaust ventilation system: A system for removing contaminated air from a space, comprising two or more of the following elements:
- (a) enclosure or hood,
- (b) duct work,
- (c) dust collecting equipment,
- (d) exhauster, and
- (e) discharge stack.
Summary of requirements
Investigations of indoor air quality often fail to identify any harmful levels of specific toxic substances. Often, employee complaints result from items such as cigarette smoke, odors, low-level contaminants, poor air circulation, thermal gradients, humidity, job pressures, lighting, work-station design, or noise.
Complaints are often of a subjective, nonspecific nature and are associated with periods of occupancy. These symptoms often disappear when the employee leaves the workplace. They include headache, dizziness, nausea, fatigue, lack of concentration, and eye, nose, and throat irritation.
Immediate effects may show up after a single exposure or repeated exposures. These include irritation of the eyes, nose, and throat, headaches, dizziness, and fatigue. These effects are usually short-term and treatable. Sometimes, the treatment is simply eliminating the person’s exposure to the source of the pollution, if it can be identified.
The likelihood of reactions to indoor air pollutants depends on several factors. Age and preexisting medical conditions are two important influences. In other cases, whether a person reacts to a pollutant depends on individual sensitivity, which varies from person to person. Some people can become sensitized to biological pollutants after repeated exposures, and it appears that some people can become sensitized to chemical pollutants as well.
Other health effects may show up either years after exposure has occurred or only after long or repeated periods of exposure. These effects (which include some respiratory diseases, heart disease, and cancer) can be severely debilitating or fatal. Thus, it is prudent to improve indoor air quality even if symptoms are not noticeable.
There are three basic strategies to improve indoor air quality:
- Source control: Usually, the most effective way to improve indoor air quality is to eliminate individual sources of pollution or to reduce their emissions. When possible, use local exhaust ventilation and enclosure to capture and remove contaminants generated by specific processes. Room air in which contaminants are generated should be discharged directly outdoors rather than re-circulated.
- Improved ventilation: Most heating and cooling systems do not bring fresh air into the building. Opening windows and doors, operating window fans, or running a window air conditioner with the vent control open increases the outdoor ventilation rate. Increase ventilation during short-term activities that can generate high levels of pollutants such as painting, paint stripping, or maintenance activities such as welding, soldering, or sanding.
- Air cleaners: Air cleaners range from relatively inexpensive table-top models to sophisticated and expensive systems. Some air cleaners are highly effective at particle removal, while others, including most table-top models, are much less so. Air cleaners are generally not designed to remove gaseous pollutants. Table-top air cleaners may not remove satisfactory amounts of pollutants from strong nearby sources. People with a sensitivity to particular sources may find that air cleaners are helpful only in conjunction with concerted efforts to remove the source.