Bathtub reglazing safety: chemicals, ventilation, and what to verify
Most bathtub reglazing jobs are completed safely every day. But this trade has a documented body count. Methylene chloride, a paint stripper still used by some refinishers, has killed at least 13 US workers since 2000. As a homeowner hiring a contractor, there are specific things you should verify before letting anyone work in your bathroom.
The real risk: methylene chloride
Methylene chloride (MEC), also called dichloromethane, is a powerful paint stripper that has been widely used in bathtub refinishing because it strips old coatings quickly. It is extremely effective and extremely dangerous in enclosed spaces. When inhaled, MEC is metabolised by the body into carbon monoxide. In a small, poorly ventilated bathroom, vapour concentrations can reach lethal levels within minutes. The vapours are heavier than air and pool at the bottom of the tub, exactly where the worker is leaning while stripping and coating.
Sources: CDC MMWR 2012, OSHA Hazard Alert on MEC in Bathtub Refinishing, ongoing OSHA fatality investigations.
Five questions to ask before you hire
Print this. Email it. Read it on the phone when you book the consultation.
What stripping chemical do you use?
Watch for methylene chloride (MEC) or dichloromethane. Safer answers: NMP-based, soy-based, or mechanical strip.
What is your ventilation setup?
A specific exhaust plan, not 'we open the window'. Look for an exhaust fan with ductwork to a window or exterior.
What respirator does your crew wear?
A supplied-air respirator or a half-face with organic-vapour cartridges. Not a dust mask. Not nothing.
Do you carry workers' comp and liability insurance?
Both. Ask for proof. If they balk, walk.
What is your warranty?
3 to 5 years on adhesion is normal. Some premium contractors offer 10. Vague warranties are a red flag.
Safer stripper alternatives
- NMP (N-methyl-2-pyrrolidone) based strippers (safer but slower)
- Soy and citrus-based strippers (biodegradable, low odour)
- Mechanical stripping (sanding only, no chemical strip)
- Benzyl alcohol formulations
Trade-off: safer alternatives are slower and sometimes less effective on stubborn old coatings. A contractor using NMP might charge an extra $50 for the longer prep. That is a fair upcharge.
During and after the job
- Strong chemical odour even with safer strippers
- Bathroom door must stay closed during work
- Open windows in adjacent rooms to vent any drift
- Pets and small children kept on another floor
- Off-gassing continues for 2 to 3 days at low levels
- Coating is fully cured and inert after 48 to 72 hours
If you are doing it yourself
DIY kit fumes are not as acutely dangerous as MEC, but they are still serious. Wear an organic-vapour respirator (around $30 at hardware stores), open every window you can, run a window fan blowing out, and take breaks every 20 minutes. Do not work alone; have someone check on you. Keep pets and children on another floor for the entire application and the first 24 hours of cure.