Finishing safety and disposal

Overview

Finishing leaves three kinds of waste: liquid (leftover finish, thinner, brush-cleaning solvent), solid (rags, dry brushes, sanding dust) and containers. Most of it is either flammable, a hazard in the environment, or both. The rules for what goes where are set locally, so this entry gives the principles from the sources and tells you where to find your own.

When to use

At the end of every session and whenever you clear out the shelf. Leftover finishes are not exempt from rules just because they are small amounts.

Materials and tools

• Original, labelled containers, with lids that seal
• A covered metal can for solvent and oil rags (see Oily rag safety)
• Chemical-resistant gloves and goggles: Fine Woodworking finds nitrile gloves excellent for general finishing and heavier neoprene for strippers, and says thin vinyl and latex gloves do not protect for long
• The phone number or website of your local household hazardous waste programme

Steps

1. Store finish in its own container. EPA says to keep products in their original containers, never remove labels, and never store hazardous products in food containers.
2. Use it up first. The best disposal is none: buy the quantity you need and finish the job.
3. Never pour finish or solvent down a drain, onto the ground or into a storm sewer. EPA warns that this pollutes the environment, can contaminate septic and wastewater systems and can injure sanitation workers.
4. Do not mix leftovers. EPA says never to mix household hazardous waste with other products: incompatible products can react, ignite or explode, and a contaminated product may become unrecyclable.
5. Take it to a household hazardous waste collection. EPA says to search for "household hazardous waste" near your postcode, or contact your local environmental, health or solid-waste agency, which may run permanent sites or periodic collection days. Even empty containers can retain residue, so handle them with care.
6. Rags and oil waste. Use the methods in Oily rag safety. OSHA 1910.106 (an employer rule) says combustible waste and residues are to be kept to a minimum, stored in covered metal receptacles and disposed of daily; copying it at home costs little.
7. Solvent cleaning. Let a brush-cleaning solvent settle and reuse the clear liquid if your local rules allow, and take the sludge to the collection site. This is common practice, not a figure from a source I opened; follow local advice.
8. Epoxy. West System says to clean up with scrapers and absorbent towels, use sand, clay or other inert absorbent on large spills, and not to use sawdust or other fine cellulose to absorb hardener.

Common problems

• Skin reaction to epoxy, dyes or finish. West System says to stop using the product if you develop a reaction, resume only after the symptoms disappear, and improve precautions; if problems persist, consult a physician. It says breathing partially cured epoxy dust increases the risk of sensitisation.
• Solvent on bare skin. Wash it off promptly and use gloves; barrier creams are suggested by West System for epoxy but are not a substitute.
• Container rusting or leaking. EPA says corroding containers need special handling; call your local hazardous-materials office or fire department.
• Outdoor water repellents and stains near plants. The Wood Handbook cautions that the fungicides in water-repellent preservatives and semitransparent stains are toxic and may be herbicides: avoid skin contact and vapours and protect plants and soil.
• A stripper containing methylene chloride. The Wood Handbook records that the US EPA banned it from noncommercial use in 2019. Do not use old stock; ask your hazardous waste site.

Safety and environment

Skin: nitrile gloves for general finishing, heavier gloves for strippers. Sensitisation can develop from repeated contact; the sources I opened document it for epoxy hardeners, and for dyes and metallic driers I found only the makers' SDS warnings, so read them. Eyes: splash goggles. Wash before eating or smoking. Disposal rules differ by state and municipality; EPA's page is the starting point for the US. This entry is US-only.

Related

• Oily rag safety: the self-heating rag problem
• Finishing shop ventilation and PPE: respirators and ventilation
• VOC regulations and low-VOC finishes
• Tabletop epoxy: epoxy handling
• Finishing on site and in small shops