Common Contaminants in Reclaimed Wood
Not all old wood is safe to reuse without precautions. Buildings constructed before 1978 may contain lead-based paint on wood surfaces. Industrial and agricultural structures may have wood treated with pentachlorophenol (Penta), creosote, or chromated copper arsenate (CCA). Railroad ties are almost always creosote-treated and should never be used for residential applications.
At GreenBoard, we screen every incoming board for these contaminants. Material with confirmed hazardous contamination is diverted to appropriate disposal streams and never enters our resale inventory. But if you are sourcing reclaimed wood independently, these are the checks you should perform.
Lead Paint Testing
Any painted reclaimed wood from pre-1978 structures should be assumed to contain lead until tested. EPA-certified lead test kits are available at hardware stores for under $15. Swab the paint surface — a color change indicates lead presence. If lead is detected, the wood can still be used if the paint is fully removed by a trained professional using HEPA-filtered equipment. Never sand lead paint without proper containment and respiratory protection.
Chemical Treatment Identification
CCA-treated wood has a greenish tint, especially visible on end grain. Creosote-treated wood (railroad ties, utility poles) has a dark, oily appearance and a distinctive tar-like smell. Penta-treated wood may appear dark brown with an oily surface. If you suspect chemical treatment, do not burn the wood and do not use it for food-contact surfaces, children's play equipment, or garden beds where it would contact soil.
Modern pressure-treated lumber (ACQ, CA-B) is considered safe for most outdoor applications but is not what we typically deal with in reclaimed stock. If you encounter green-tinted modern pressure-treated wood in a demolition, it can generally be reused for outdoor non-food-contact applications.