SACRAMENTO - A number of consumer products and home appliances, none of which are tested or regulated for ozone emissions, emit enough ozone to pose potential health risks to their users, a new California Air Resources Board (CARB) study has found.

The study, “Evaluation of Ozone Emissions and Exposures from Consumer Products and Home Appliances,” highlights a critical gap in consumer protection. The paper was published online (http://onlinelibrary.wiley.com/doi/10.1111/ina.12307/pdf) today in the journal “Indoor Air.” 

The CARB study measured ozone emissions and impacts on indoor ozone levels and associated exposures from 17 consumer products and home appliances that emit ozone either intentionally or as a by-product of their functions. In all, five products in three categories emitted ozone at levels that may result in potential health effects.  The five products included a residential ozone laundry water treatment appliance, two fruit and vegetable washers, and two facial steamers. Due to its strong oxidative ability, ozone is widely advertised for disinfection or odor removal by manufacturers. 

The use of some products was estimated to contribute up to 87 percent of total daily exposures to ozone. An ozone laundry water treatment system, when used for one wash cycle, increased room ozone concentrations by 0.11 parts per million (ppm), which is higher than California’s 1-hour health-based air quality standard for outdoor ozone (0.09 ppm).  And, it increased personal exposure concentrations by as much as 0.42 ppm. The personal exposure concentration is the concentration that users of the product are exposed to as a result of their close proximity to the product. This exposure level exceeds the level of a Stage 2 smog alert, which is called when 1-hour average outdoor ozone concentrations reach 0.35 ppm. Such an alert has not been called in California since 1988. 

For some products, one use does not increase room ozone concentrations markedly, but repeated use can result in high exposure concentrations. For example, a fruit and vegetable washer increased personal exposure concentrations by an average of 2.55 ppm, or more than 28 times higher than California’s 1-hour health-based standard for outdoor ozone (0.09 ppm), when it was used for three continuous wash cycles with reused water. 

While many consumer products and home appliances can emit ozone, ozone emissions have only been regulated for air cleaners. Ozone generators – purported air cleaners that intentionally produce ozone and which are inaccurately marketed as producing “safe” levels of activated oxygen that remove indoor air pollutants – and other types of air cleaners, such as some ionizers and electrostatic precipitators, have been found to increase indoor ozone concentrations to harmful levels. In response, CARB adopted a regulation in 2007 to limit ozone emissions from indoor air cleaning devices to no more than 50 ppb. ARB has certified over 1,600 models of air cleaning devices (https://www.arb.ca.gov/research/indoor/aircleaners/certified.htm) that meet the ozone emission standard.  In addition, CARB has identified a list of potentially hazardous ozone generators sold as air purifiers. 
 
The recent CARB study concluded that further research and actions, such as product design changes, development of industry standards, and/or regulations limiting ozone emissions from these other types of products, appear to be needed. CARB has developed a web page (https://www.arb.ca.gov/research/indoor/ozoneproducts.htm) for more information on this study, including a list of ozone-emitting products (https://www.arb.ca.gov/research/indoor/hazardousozoneproducts.htm) similar to those studied .  The U.S. Consumer Products Safety Commission is the agency with authority over consumer products. CARB has shared the results of its study with the CPSC. 

Ground level ozone, a key ingredient of smog, is a harmful air pollutant that can cause serious health effects and environmental impacts. These include respiratory problems such as increased asthma symptoms, and even premature death, as well as crop and forest damage.  The use of some of the products tested can contribute a significant fraction of total daily exposure to ozone. Although their market share is unknown, these devices can easily be obtained due to their low price and widespread advertising online and on television.

For a fact sheet on results of the study on ozone emissions from consumer products and home appliances, visit here (https://www.arb.ca.gov/research/indoor/ozoneproductsfactsheet.pdf). 
B-roll is available here (https://www.arb.ca.gov/videos/ozone_devices_broll.mp4). 


 
The top three ozone emitters in a recent CARB study: ozone laundry water treatment system (left) and fruit and vegetable washers.