Compliance
F032 to F035: wood preserving waste codes
The wood treating listings, and why F032 brings dioxin treatment standards with it.
F032, F034 and F035 are the RCRA listings for wastewater, process residuals and sludges from wood preserving. F032 covers chlorophenolic formulations, F034 covers creosote, and F035 covers arsenical or chromate formulations.
Source: 40 CFR 261.31The listings
- F032, wastewater, process residuals and spent formulations from wood preserving using chlorophenolic formulations, including pentachlorophenol
- F034, the same waste streams from processes using creosote formulations
- F035, the same waste streams from processes using inorganic preservatives containing arsenic or chromium
Why F032 is the expensive one
Chlorophenolic preservatives carry dioxin and furan contamination as a manufacturing byproduct. F032 therefore carries dioxin treatment standards under land disposal restrictions, which limits the treatment routes available and raises the cost well above F034 or F035.
There is a further trap. A facility that once used chlorophenolics and later switched to creosote may still generate F032 from residual contamination in the treatment cylinders, drip pads and process equipment. The listing follows the contamination, not the current product.
Drip pad requirements
Wood preservers operating drip pads have their own standards at 40 CFR Part 265 Subpart W.
- Drip pads must be sealed, curbed and free of cracks or gaps
- Residue removal at least once every 90 days
- Annual inspection and documented condition assessment
- Run on and run off control for outdoor pads
- Records retained for three years
Common questions
Is treated lumber itself a hazardous waste?
Generally no. Arsenical treated wood that fails the toxicity characteristic is excluded from hazardous waste regulation under 40 CFR 261.4(b)(9) when discarded by the user. The exclusion covers the treated wood, not the process waste from treating it.
Does F035 apply to CCA operations?
Yes. Chromated copper arsenate is an inorganic preservative containing both arsenic and chromium, so process wastewater and sludge from CCA treating carries F035, and commonly D004 and D007 as well.
What if we used chlorophenolics years ago?
Residual contamination can still generate F032 from cylinders, sumps and drip pads. If the site history includes pentachlorophenol, that history needs to inform the waste determination rather than the current formulation alone.
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This page summarizes federal requirements and is not legal advice. State programs can be more stringent than the federal baseline. Verify against current federal and state regulations before acting. Last reviewed September 2026.