Treated wood gets its light green color due to pressure treatment of the wood. While such treatment of chemical preservatives being forced deep into the wood’s cellular structure in a closed cylinder under pressure is beneficial so as to create a chemical barrier against termites and decay for a long period of time. Treated wood is said to resist decay and termites for about 40 years or more. It is useful for interior as well as exterior construction. Without decay, the pressure treated lumber can be immersed in water. It can also be buried without rotting. It can be exposed to insects without being destroyed.
The three main categories of preservatives, also acting as pesticides, used for the treatment are water-borne, oil-borne and creosote. Wood treated with water-borne preservatives is mainly used for industrial, commercial and residential products and applications. Creosote treated wood is used for fences, docks, railroad tracks, etc. Wood treated with oil-borne preservatives is used in industries, railroad ties, etc. Wood preserving solutions, herbicides or insecticides bought for home or garden use, do not usually contain “Penta” which is an oil-borne preservative.
While there are numerous advantages of using pressure treated lumber, let us now see a few hazards caused from it.
Extreme care needs to be taken as the selection, usage and disposal of treated wood wastes could cause adverse health and environmental impacts.
Hazards of pressure treated lumber
- Most of the wastes which are found in the open dump sites are those coming from commercial construction and demolition activities.
- Burning or grinding of pressure treated wood and its improper use creates human health and environmental concerns.
- Exposure to inorganic arsenic, creosote or penta (pesticides used in pressure treated wood) are also quite hazardous. Thus, handling and disposal of wood treated with pressure must be done with great caution.
- Treated wood which is ground (for use as mulch or in compost) extensively exceeds cancer-risk.
- Toxic gases released after burning pressure treated wood create exposure for neighboring residents or businesses to these fumes.
- The treatment chemicals within the wood do not degrade, while the wood itself does. So, the treated chemicals inside the wood persists.
- Long- term exposure to arsenic (found in some types of pressure treated lumber), increases the risk of bladder, lung and skin cancer over a person’s lifetime.
It is the chemicals used in the treatment process, and not the failure of the performance of the pressure treated wood, which is a danger to the consumers. Humans (especially the householders), who come into the contact with chemicals can be at a risk of hazardous effects. This is because the chemicals have a tendency to leach into their surrounding environment.
Remodeling projects involving older woods or any such projects utilizing reclaimed lumber should be evaluated in the light of potential toxin exposure.
Alternatives to treated wood
Although there are above listed impacts of using pressure treated lumber, it is helpful to know the alternatives to it. Lumber products of lower toxicity can be used as an alternative to pressure treated ones. This can also help to prevent the concerns of future waste disposal of treated wood.
- Redwood (includes cedar and cypress) is an excellent resistant to insects and decay. It is also easier to saw and nail. However, it can be more expensive and can be susceptible to moisture.
- High density polyethylene (HDPE), thermoplastic serves as a good weather- resistant and is also suitable for agricultural uses. HDPE is a superb chemical-resistant. However, it is a poor UV-resistant and cannot be rated for structural use.
FAQs
1. How are children exposed to hazards of pressure treated wood?
Ans. Children can be exposed to arsenic – a non-commercial pesticide used for treating the wood. Through the skin contact with the wood and their hand-to-mouth activity while playing, children can be exposed to the risks involved. Arsenic from treated wood, slowly leaches on to the surrounding soil, thus exposing children who come in contact with such contaminated soil to the hazardous consequences.
2. How can such risks arising from treated wood be lessened?
Ans. Following are a few ways which can lessen the risks arising from pressure treated wood:
- Parents should be aware and careful about their children who play outdoors or in any way come in contact with exterior wood such as play sets, decks, etc. Children must wash hands after playing outside and before eating. Parents should also discourage children to eat while on pressure treated wood used at playground.
- Usage of a duct tape to tape the hand pegs of a play set can lessen the risks extensively.
- Growing vegetables in beds lined with treated wood should be avoided.
- If a tablecloth is placed on picnic tables, it helps to avoid the direct contact with the treated wood, thus reducing the risks involved.
- While drilling, sawing or sanding arsenic-treated wood, usage of goggles, gloves or dust masks should be encouraged.
