VOLATILE ORGANIC COMPOUNDS (VOCs)
Definition and Background
The term Volatile Organic Compounds refers collectively to a large number of organic vapours which contaminate indoor air. Over 300 VOCs have been identified in indoor air at concentrations exceeding 1 part per billion (ppb). Among the most commonly reported VOCs are formaldehyde, ethylbenzene, benzene, o-, m-, and p-xylenes, styrene, chlorinated solvents, including 1-1-1-trichloroethane, tetrachloroethylene, and trichloroethylene, carbon tetrachloride, dichlorobenzene, methylene chloride and chloroform. VOCs are consistently found in higher concentrations indoors than outdoors. Within a structure their concentrations are variable with time and location, suggesting the presence of significant indoor sources.
The sources of VOC are numerous and include building materials, consumer products, cleaning solvents, paints, adhesives, cosmetics, hot water, and indoor combustion sources. Relatively little information exists on the contribution of individual sources to indoor levels of VOC.
In New Zealand a significant VOC is formaldehyde.
This chemical is used to manufacture particle board, (as used in floors, doors, joinery and cabinetry for bathrooms, kitchens, furniture, etc.).
While both main surfaces of the particle board may be sealed, (at the time the particle board is manufactured) with a lacquer or a varnish, when any piece of particle board is cut, (as when manufacturing kitchen joinery cabinets for a new home) the “raw edges” start to “leach out” formaldehyde into the indoor environment, through the unsealed cut end of the particle board. This “leaching” continues for many years, constantly contaminating the indoor air with a proven health hazard. For more details on the serious health effects of formaldehyde, refer to the VOC section of our reference links. (use the link at the top of the page).
Acute exposure to high levels of many VOCs is associated with irritation of the eyes and upper respiratory tract. Concern over chronic health effects of VOCs derives from occupational and animal toxicity studies. Many VOCs in indoor air are proven carcinogens. The chronic and acute health effects of VOCs in complex mixtures over a range of concentrations encountered in buildings are not well understood or researched.
Control of VOC contamination of indoor air is as simple as adequate ventilation by dilution. There is no better way to acheive a healthy indoor environment, than to ventilate with an HRV.
Control can also be accomplished through a combination of identification and removal of sources of indoor VOCs, but as almost every single item of construction and furniture / furnishing in a home are produced by the use of some chemical, it is virtually impossible to remove the sources individually. eg…
Formaldehyde leaching from particle board in kitchen and bathroom cabinets, furniture and joinery .
Solvents, plastics / plastisols leaching from wallpaper, paints, varnishes, upholstery foam, aerosols, cleaners, disinfectants, etc.
Chlorines leaching from drapes and furnishing materials, bedlinnen, carpets, underfelts, lino, and other floor coverings.
Chemicals from cleaning agents, aerosols, oven cleaners, fly spray, polish sprays, bathroom cleaners, soap products, disinfectants, hair sprays, nail polishes, hobby chemicals etc etc.
The following article appeared in The NZ Herald on Friday , March 2, 2001:
Home sweet home a danger zone
by Catherine Masters
The average New Zealander spends hours every day in the comfort of home watching television and using various appliances.
Children are often plonked in front of the electronic babysitter for hours.
Britain’s Health Which? consumer magazine says that not just the TV but all sorts of appliances and other items in the home may be bad for health, and people may be unwittingly exposing themselves to toxic build ups affecting the immune system.
It suggests that this exposure to everyday items — including toxins in furniture, food packaging, cosmetics and toys — may be causing medical problems such as asthma, cancer and even genital malformation.
David Russell, of New Zealand’s Consumers Institute, says we should not be overly alarmed by such reports, “but certainly we should take note.”
Many home products containing chemicals were unnecessary, but were promoted by smart marketing.
“There is pretty good evidence that a little bit of dirt and a few bugs around the place help you build up your immune system.”
“There are things to be careful about. We shouldn’t overdo these things… It is a question of moderation.”
The Green Party’s Sue Kedgley, on the other hand, criticises the way the whole area of chemicals and toxins is put in the too-hard basket and ignored.
“Who in New Zealand is monitoring, doing safety evaluations of these sorts of products? Basically, if it’s been approved in some far-distant land like America, we accept it, no question.”
Twenty-five per cent of New Zealanders were dying of cancer but we did not know the underlying reasons.
A Scandinavian study of nearly 50,000 identical twins had found that the causes of cancer were mainly environmental, said Ms Kedgley.
The British report highlights three chemicals causing concern:
Brominated Flame Retardants, used to reduce flammability in furnishings and electrical goods. They appear to enter the air as gases or dust and are inhaled. Some have been found in blood and breast milk. They act as endocrine disrupters, and tests on animals have linked them to miscarriages, learning difficulties and changes in the immune system.
Phthalates, found in toys, food packaging, building materials and nail varnish and perfume. They are used mainly to soften PVC plastic. They, too, act as endocrine disrupters. They enter the body in several ways — from food packaging seeping into our food, through cosmetics applied to the skin, or through children sucking toys containing them.
Artificial musks, used in perfumes, cosmetics and household products, such as fabric conditioners and air fresheners. Although they are generally thought to be safe in cosmetics, their quantity should be reduced because of their tendency to bio-accumulate.
The report says the problem is not just the substances themselves but the effects of bio-accumulation. The chemicals accumulate in the environment and In our bodies without breaking down, so their toxic presence lingers.
The main dangers are hormone or endocrine associated chemicals. These mimic or block the effects of hormones in the body, in particular the effect of the female hormone, oestrogen.
This has been linked to falling sperm counts, birth defects, breast and prostate cancer, immune-system breakdown and physical and mental problems in children.
Louise Gitter, who led the Health Which? investigation, admitted that some of the risks were not proven.
“We can’t say that if you come in to contact with a TV you’ll definitely get cancer, but there are a number of concerns that chemicals pose a risk to the environment and to health.”
The European Commission is working on a strategy to tighten regulation on chemicals in domestic products.
But until then, the World Wide Fund for Nature has some simple suggestions for reducing the risks.
- Wash children’s toys regularly.
- Wash and peel fruit and veges.
- Buy organic food from delicatessens with less packaging.
- Keep pesticides from children.
- Wash your hands before meals.