Many Cleaners, Air Fresheners May Pose Health Risks When Used Indoors

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This was originally posted by a member of Mcs-toxic-injuries

 

Many Cleaners, Air Fresheners May Pose Health Risks When Used Indoors

http://www.sciencedaily.com/releases/2006/05/060524123900.htm

Source: University of California - Berkeley

May 24, 2006

 

Science Daily — 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.

 

The study is the first to measure emissions and concentrations of primary and

secondary toxic compounds produced by these products under typical indoor use

conditions, and it examines the potential hazards of small-scale yet

widespread utilization of an array of products designed for household use.

 

" We've focused a lot of effort in the last decades on controlling the big

sources of air pollution and on the chemicals in consumer products that

contribute to outdoor ozone formation. However, now we've learned that we need

to pay

attention to other aspects of pollution sources that are right under our nose, "

said William Nazaroff, a UC Berkeley professor of environmental engineering

and the study's lead author.

 

To comply with its mandate to protect public health and welfare, for the past

four decades the California Air Resources Board (ARB) has been developing and

implementing regulatory programs to reduce air pollution in the state. These

regulations also cover emissions of volatile organic compounds from consumer

products used in homes and institutions.

 

Several years ago, when a handful of new studies raised the concern that

consumer products may be contributing to indoor pollution levels in ways that

were

not fully understood, the ARB commissioned Nazaroff and his team to study the

problem.

 

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.

 

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.

 

Ethylene-based glycol ethers are common, water-soluble solvents used in a

variety of cleaning agents, latex paints and other products. They are classified

as hazardous air pollutants under the U.S. Environmental Protection Agency's

1990 Clean Air Act Amendments and as toxic air contaminants by California's Air

Resources Board. Their toxicity varies with their chemical structure.

 

Terpenes are a class of chemicals found in pine, lemon and orange oils that

are used in many consumer products either as solvents or to provide a

distinctive scent. Although terpenes themselves are not considered toxic, some

recent

studies have shown that they may react with ozone to produce a number of toxic

compounds. (The primary constituent of smog, ozone enters the indoor

environment from infiltration of outdoor air, but is also produced indoors by

some

office machines such as copiers or printers, and by some devices marketed as

" air

purifiers " that purposely emit ozone into the indoor environment.)

 

The research team's first task was to determine which household products

contain terpenes and glycol ethers, and in what quantities. It compiled a list

of

the household cleaners and air fresheners available at any of five chain

retail outlets in Northern California, then examined the labels and advertising

claims (e.g. " pine-scented " ) for these products and reviewed available product

data sheets. Based on this information, they selected the 21 products most

likely to contain significant amounts of terpenes and ethylene-based glycol

ethers:

four air fresheners and 17 cleaning products, including at least one each of

disinfectants, general-purpose degreasers, general-purpose cleaners, wood

cleaners, furniture maintenance products, spot removers and multi-purpose

solvents.

 

A complete chemical analysis of these 21 products revealed that:

 

• Twelve contained terpenes and other ozone-reactive compounds at levels

ranging from 0.2 to 26 percent by mass.

 

• Six contained levels of ethylene-based glycol ethers of 0.8 to 9.6 percent

by mass.

 

• Among the four air fresheners studied, three contained substantial

quantities of terpenes (9-14 percent by mass)

 

When the researchers tested the terpene-containing products in the presence

of ozone, they found that reactions produced very small particles with

properties like those found in smog and haze; other oxidation products; and

formaldehyde, a respiratory irritant that is classified as a Group 1 carcinogen.

(This

designation by the International Agency for Cancer Research is reserved for

substances for which there is sufficient evidence to conclude that they cause

cancer in humans.) The amounts of terpenes that were converted into these

pollutants was dependent on the amount of ozone present.

 

After completing their chemical analyses, the researchers ran a series of 18

experiments to determine the levels of exposure people might be subjected to

when using the products in a confined space. The tests were conducted in a

230-square-foot room with ventilation at an ordinary level which provided

approximately one air change every two hours. In some tests of

terpene-containing

products, ozone was introduced into the room at levels mimicking those that

could

occur in households or offices.

 

The products were used in various ways according to package directions: some

at full-strength and others at various dilutions as recommended on their

labels. In some tests, used cleaning supplies such as paper towels and sponges

were

left in the room. In others, supplies were promptly removed.

 

The tests produced various results - some reassuring, and some raising

concerns.

 

The good news, the researchers reported, is that when people use the products

under ordinary circumstances, their exposure to ethylene-based glycol ethers,

formaldehyde and fine particles will normally not reach guideline values:

that is, levels set by regulatory agencies as the maximum exposure levels

believed to be safe. However, the authors pointed out, because formaldehyde is

also

released from other sources such as plywood and pressed wood products that are

found in most buildings, any increase in formaldehyde emissions is

undesirable.

 

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.

 

The report is an important milestone that highlights the need to investigate

potential health effects of ultrafine particles produced in such reactions,

said Bart Croes, chief of the ARB's Research Division.

 

" Dr. Nazaroff and his team have done a very thorough scientific assessment of

the emissions from cleaning products and how they contribute to exposures of

the users, " Croes said. " Their results indicate that we need to look beyond

the directly emitted compounds. "

 

The study cost $446,865, an amount wholly funded by the ARB.

 

The report's other authors are Beverly K. Coleman, a UC Berkeley Ph.D.

student with Nazaroff; Hugo Destaillats, Alfred T. Hodgson, Melissa M. Lunden

and

Brett C. Singer, all at Lawrence Berkeley National Laboratory; DeLing Liu, who

was at UC Berkeley when she conducted the work but is now with the Jet

Propulsion Laboratory in Pasadena, Calif.; and Charles J. Weschler, at the

University

of Medicine and Dentistry of New Jersey and the Technical University of

Denmark.