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Ozone emissions from a "personal air purifier".
T J Phillips1, D P Bloudoff, P L Jenkins
1California Air Resources Board, California Environmental Protection Agency, Sacramento, USA. tphillip@arb.ca.gov
Journal of Exposure Analysis and Environmental Epidemiology
|January 19, 2000
Summary
Personal air purifiers (PAPs) can emit ozone, creating high concentrations in the user's breathing zone. These ozone levels exceed health standards, posing a risk to users even in well-ventilated areas.
Area of Science:
- Environmental Health Science
- Air Quality Monitoring
- Occupational Health
Background:
- Personal air purifiers (PAPs) are marketed as negative ion generators for air purification.
- These devices may emit ozone, a respiratory irritant, into the user's immediate breathing zone.
Purpose of the Study:
- To measure ozone emissions from a wearable personal air purifier (PAP).
- To assess potential worst-case human exposure to ozone at mouth and nose level.
- To compare measured ozone levels against established air quality standards.
Main Methods:
- Ozone concentrations were measured at varying distances (1-6 inches) above two PAP devices (new and used).
- Concurrent measurements of temperature, humidity, atmospheric pressure, and room/outdoor ozone levels were taken.
- Ozone emission rates were calculated, and the impact of dust on emissions was tested.
Main Results:
- Ozone levels directly above PAPs ranged from 268-389 ppb at 1 inch.
- Ozone emission rates were estimated at 1.7-1.9 µg/minute.
- Even with dust, ozone levels exceeded California and US outdoor air quality standards.
Conclusions:
- Wearable PAPs can generate significant ozone concentrations in the user's breathing zone.
- These ozone levels surpass health-based air quality standards.
- Users may be exposed to harmful ozone levels independent of ambient air quality.