Any formulation sold as a timber preservative, or antisapstain treatment, is required to be an approved substance under the New Zealand HNSO Act 1996.
One of the Default Controls applied to most of these formulations is that they can only be used at industrial timber treatment facilities.
The treatment facilities and their operation are subject to approvals /regulations under other legislation, e.g. Resource Management Act , and to meet any local Council requirements.
In addition the timber treatment industry has developed and has approved a Best Practice Guideline for the Safe Use of Timber Preservatives & Antisapstain Chemicals.
A Safety Data Sheet or handling & use information is usually available for the treated timber product from the supplier.
This will provide information on any hazardous ingredients, the concentration range and recommended safe handling and disposal information.
Care is needed to avoid the inhalation of any wood dust whether it is from untreated or chemically treated timber. Whenever possible the cutting, sanding or machining of timber should be outdoors to avoid a build up of air-borne wood dust.
The Workplace Exposure Standards set by OSH ,New Zealand Department of Labour for wood dust (as sensitiser) are:
Softwoods TWA 5 mg/m3 STEL 10 mg/m3
Hardwoods* TWA 1 mg/m3 (* certain hardwoods such as oak, beech)
These maximum concentrations apply to untreated timber. Provided a dust mask is used and the timber is cut and machined outdoors or where there is good ventilation, e.g. mechanical ventilation equipment, the wood dust levels are unlikely to constitute a health hazard.
Cloth or leather gloves are recommended to protect hands from splinters and abrasion. If timber surfaces are damp or wet then waterproof gloves are recommended.
Eye protection provided by safety glasses or goggles, is recommended to protect eyes from wood dust.
Wash clothing that may be contaminated with wood dust residues before re-use and wash separately from normal household laundry.