Many cleaners, air fresheners may pose health risks when used indoors

From a press release of the same title from University of California - Berkeley:

When used indoors under certain conditions, many common household cleaners and air fresheners emit toxic pollutants at levels that may lead to health risks, according to a new study by researchers at the University of California, Berkeley, and Lawrence Berkeley National Laboratory. Exposure levels to some of the pollutants - and to the secondary pollutants formed when some of the products mix with ozone - may exceed regulatory guidelines when a large surface is cleaned in a small room or when the products are used regularly, resulting in chronic exposure, according to the study.. Four years in the making, the team's 330-page study and report, "Indoor Air Chemistry: Cleaning Agents, Ozone and Toxic Air Contaminants," was posted online by the ARB on Wednesday, May 10, at http://www.arb.ca.gov/research/apr/past/indoor.htm. The ARB asked Nazaroff and his team to focus their work in two areas: an investigation of toxic air contaminants in household cleaning products and air fresheners, especially a class of chemicals known as ethylene-based glycol ethers; and an examination of the chemistry that occurs when such products are used indoors - in particular, products that contain a reactive group of chemicals called terpenes... In several realistic use scenarios, the tests showed that people could be exposed to potentially dangerous levels of toxic pollutants. The scenarios included:

• Cleaning in a small, moderately ventilated bathroom. In calculations based on emissions from one of the glycol-ether containing products, the team found that a person who spends 15 minutes cleaning scale off of a shower stall could inhale three times the "acute one-hour exposure limit" for this compound set by the California Office of Environmental Health Hazard Assessment.
• Air freshener and ozone in a child's bedroom. This scenario could occur when people use both air fresheners and ozone-generating devices simultaneously in a room. This could lead to exposures to formaldehyde that are 25 percent higher than California's guideline value. Because other sources of formaldehyde could also be present in the room, exposure to formaldehyde would probably be even higher, the report states.
• Cleaning when outdoor ozone levels are high. This scenario simulates an apartment in Southern California on a day when the mid-afternoon outdoor ozone concentration is high. A person who stays in the kitchen for two hours after using a moderate amount of one of the terpene-containing products would breathe in about one quarter of the total daily guideline value for particulate matter.
• Multi-house cleaning by a professional home cleaner. Under this scenario, a person who cleans four houses a day, five days per week, 50 weeks per year, would take in about 80 micrograms per day of formaldehyde, double the guideline value set by California's Proposition 65. In addition, the person's intake of fine particulate matter during the hours spent cleaning would exceed the average federal guideline level for an entire year. These quantities are in addition to the formaldehyde and particulate matter that the person would be exposed to from all other sources and activities during the year.

The take-home message from these studies, according to Nazaroff, is that everyone - but especially cleaning professionals - should be cautious about overuse of products with high levels of ethylene-based glycol ethers and terpenes. Rooms should be ventilated during and after cleaning, some products should be used in diluted solutions as opposed to full-strength, and cleaning supplies should be promptly removed from occupied spaces once cleaning is done. Also, people should avoid the use of ozone generators or ionizing air cleaners, especially in the same space where terpene-containing cleaning products or air fresheners are being used.