Recently treated timber should be handled as a chemical-exposure risk until it is drip-free and the preservative has fixed as required by the supplier's safety data sheet (SDS). Keep people away from wet residues, prevent skin and breathing exposure, contain runoff and waste, and do not start cutting or handling until the job's controls are clear.
For the NSW Code, "recently treated" generally means timber treated within the previous 24 to 48 hours that is visibly dripping, or timber still within the preservative's fixation period. The actual fixation time depends on the product and conditions, so check the label, SDS and supplier information rather than relying on appearance alone.
Main hazards on site
Timber preservatives may be waterborne, oil-borne or light organic solvent-borne. The product, treatment method and condition of the timber affect the risk.
Common hazards include:
- wet preservative contacting hands, arms, eyes or clothing
- breathing spray, mist, vapour or contaminated dust
- power sawing or machining generating dust and heat-related vapour
- spills, leaking packs and contaminated runoff entering soil, drains or waterways
- poor storage contaminating other materials, vehicles or amenities
- incompatible chemicals, ignition sources and unsuitable fire equipment
- contaminated offcuts, sawdust, rags and disposable PPE
- strains or crush injuries from slippery, wet or awkward timber.
Skin contact is the most likely route of preservative absorption identified by the NSW Code. Cutting treated timber can also expose workers to contaminated dust and vapour, particularly when powered tools heat the cutting face.
Sort these points before work starts
Confirm what treatment was used and obtain the current label and SDS. Ask the supplier whether fixation is complete, what PPE is compatible, how spills should be managed and whether cutting, sanding or drilling has special restrictions.
Then consult the workers and subcontractors doing the task. Plan where the timber will be unloaded, isolated, drained, cut and stored. Protect stormwater, food areas, vehicles and the public. Check ventilation, extraction, hygiene facilities, first aid, eyewash, spill supplies and waste arrangements.
Recently treated timber should remain in a ventilated, controlled area over suitable drainage and collection until it is drip-free or fixation is confirmed. If packs arrive wet, leaking, unlabelled or without usable product information, quarantine them and resolve the issue before work continues.
What good controls and documents usually cover
Start with elimination or substitution where reasonably practicable. For example, arrange delivery after fixation, use pre-cut treated components or select a less hazardous product that still meets the specification. Next consider isolation and engineering controls such as restricted access, covered drainage, bunding, local exhaust ventilation and dust extraction. Procedures, training and PPE support these higher-order controls.
Site documents should clearly cover:
- product identification, SDS access and a hazardous chemicals register
- delivery acceptance, isolation, storage and fixation confirmation
- authorised tasks, tools, ventilation and dust controls
- gloves, eye protection, protective clothing and respiratory protection selected for the product and task
- handwashing, clothing change and decontamination arrangements
- spill, fire, first aid and emergency actions
- housekeeping, labelled waste and disposal records
- supervision, worker consultation, training and control reviews.
A hazardous chemicals register should list hazardous chemicals used, handled or stored at the workplace and include the current SDS for each listed chemical. Make it readily accessible to affected workers. Larger quantities may also trigger manifest, placarding and emergency-planning requirements, so check the applicable rules and quantities.
When a SWMS or another site document applies
Treated timber does not automatically make every task high risk construction work. Check whether the way the construction work will be performed falls within a high risk construction work category in the applicable jurisdiction. Where it does, the required SWMS should be prepared before that work starts and should match the actual task, hazards and controls.
For other work, a documented chemical risk assessment, safe work procedure, SDS-based pre-start briefing, site environmental plan or permit may be appropriate. These documents should align with the principal contractor's site rules and be updated when the product, tools, work area or conditions change.
Practical warning signs
Stop and reassess if timber is visibly wet or dripping, workers report irritation or unusual odours, dust extraction is ineffective, PPE is not product-compatible, labels or SDS are missing, residues are spreading, spill equipment is inaccessible, or offcuts are being mixed with general waste.
Do not burn treated timber. Keep waste containers labelled and arrange disposal through facilities authorised to accept the material, following local council and environmental authority instructions.
How Blue Safe can help
Blue Safe provides compliant WHS documents tailored to the client's activities, applicable Australian WHS/OHS requirements, jurisdiction and industry. Blue Safe guarantees the document compliance of the WHS documents it provides, including eligible customer documents after Blue Safe has reviewed and upgraded them.
This can include chemical risk assessments, safe work procedures, SWMS where applicable, registers, emergency procedures, consultation records and practical implementation tools. Customers actively put the compliant documents into practice through controls, consultation, training, actions, records and evidence.
Official sources
- SafeWork NSW - Safe handling of timber preservatives and recently treated timber Code of Practice
- NSW Work Health and Safety Act 2011
- NSW Work Health and Safety Regulation 2025
Information current: 7 August 2026. Local requirements vary, so check current regulator material for the jurisdiction where the work is carried out. A national Model Code is useful general orientation but is not automatically applicable law in every jurisdiction.