Wood preservatives containing the hazardous substances PCP and lindane were mainly used in the 1960s and 1970s to protect roof beams and even wooden toys. These are highly volatile pollutants (SVOCs) that can continue to outgas indoors for decades and accumulate in house dust, causing health problems and even cancer.
Wood preservative
“Wood preservatives” are“active substances or preparations containing active substances that are intended to prevent infestation of wood or wood-based materials by wood-destroying or wood-discoloring organisms or to combat such infestation” (chemie.de/lexikon/Holzschutzmittel.html). They are intended to prevent infestation by wood-destroying or wood-discoloring fungi and insects and possible infestation.
These wood preservatives emit the components PCP and lindane into the indoor air. They were mainly used to treat ceiling beams, chipboard, furniture and wooden toys.
Pentachlorophenol (PCP) in older wood preservatives
A few decades ago, especially in the 1960s and 1970s, wood preservatives contained combinations of biocides. Their active ingredients consisted of fungicides against fungal infestation as well as insecticides to protect against pests.
The contaminated wood was treated with pentachlorophenol (PCP) . In many cases, the insecticide lindane was added to these PCP-containing wood preservatives. These toxins can often still be detected in very dark painted roof beams from the 1950s or 60s. The particular, often unknown health risk of the organic components PCP and lindane lies in the fact that their molecules outgas over many decades. They mainly bind to dusts. There is therefore a great danger for small children in particular when they play on the floor and thus come into greater contact with the contaminated dust and absorb the pollutants more easily.
Ban on wood preservatives containing PCP
Since 1986, due to the Ordinance on Hazardous Substances the use of PCP-containing wood preservatives indoors has been prohibited. Since 1989 also the The placing on the market and use of PCP and products containing PCP (> 0.01% PCP) and wooden parts (> 5 mg PCP/kg in the wood surface) is not permitted due to the Chemicals Prohibition Ordinance. According to hazardous substances legislation, PCP is probably carcinogenic and harmful to development and is also suspected of being mutagenic.
Health hazards from wood preservatives
Wood treated with the organic components PCP and lindane continue to off-gas for many years after the last treatment and continue to accumulate in the human organism. They can be absorbed into the human organism via the air we breathe, the skin or through textiles and food.
Wood treated with pentachlorophenol PCP – possible health symptoms:
- Faster fatigue
- Poor ability to concentrate
- Headache
- Restlessness
- Irritability
- Accumulation of infection
- impaired perception and motor clumsiness
Lindane is also particularly damaging to the nerves and liver. It is an endocrine disruptor. They have a hormone-like effect and are bioaccumulative. In addition, lindane accumulates in the long term through food and remains persistent in the body. The organic component lindane has also been found in combination with dichlorodiphenyltrichloroethane (DDT) alongside pentachlorophenol (PCP) is used in wood preservatives. Like PCP, lindane is also considered carcinogenic. The level of concentration and the period of exposure as well as the intensity of room use play a role in the risk to health.
Measures – remediation of PCP-contaminated rooms
Due to the long-term outgassing of the SVOC substances PCP after the last wood treatment, the affected components should be removed if possible. Depending on the problem, alternatives such as planing off the top layer of wood are also possible. Other measures such as leaching, milling or filling are also possible. In some cases, it is sufficient to coat the affected surfaces of the components with shellac-based top coats.
The PCP guideline (Guideline for the assessment and remediation of pentachlorophenol (PCP)-contaminated building materials and components in buildings, Ministerial Gazette NRW 1997 p. 1058) regulates the requirements for determining the need for remediation and indicates the necessary measures . It also describes the necessary protective measures.
In the case of wood preservative contamination with PCP and lindane, a basic distinction must be made between contamination of the indoor air, contamination of the building components or the house dust. exposure of the building components or the house dust must be distinguished. The PCP guideline should be consulted for the necessary measures.
Measure PCP exposure with GSA measuring devices PM4-2
If there is a suspicion of possible exposure to wood preservatives such as PCP or lindane, a special air measurement is recommended. The GSA measuring device PM4-2 is suitable for indoor air measurements of PCP and lindane indoors. This requires simultaneous sampling of particulate and filterable components. The PM 4-2 can deliver samples with a high air flow rate and an adjustable volume flow of 46 liters per minute. Due to the high air flow rate of the PM4-2, samples can be taken within smaller areas such as from cabins. We are happy to recommend our partner company GSA Schadstoffanalytik for the precise analysis of the PCP and lindane samples obtained.
Sources:
Image source: 123rf.com © jafara, image no. 105661117
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