The Dangers of Refinishing a Bathtub Using Methylene Chloride

Source: Ioana Davies - 123RF

OSHA and the National Institute for Occupational Safety and Health (NIOSH) warn that at least one bathtub refinisher has died each year since 2000 from methylene chloride exposure.

These workers had been working alone, in poorly ventilated bathrooms, with inadequate or no respiratory protection, and no training about the hazards of methylene chloride.

Workers often spray or pour a bathtub-stripping product into the basin of the tub and then brush the product onto the tub surface.

Since methylene chloride is a volatile organic compound that will evaporate faster when sprayed, brushed, or poured, the chemical vapors can quickly build up in small spaces.

Moreover, because methylene chloride evaporates quickly (it has a high vapor pressure), vapors can collect in the bottom of a bathtub and in the worker’s breathing zone when working in the bathtub.

This situation creates dangerously high concentrations of methylene chloride and even replaces the breathable air.

Exposure to as little as six ounces of methylene chloride-based material has been enough to cause death.

Aside from using the proper protection and getting training, workers and do-it-yourselfers should learn about substitute agents and techniques for stripping tubs, such as benzyl alcohol and scraping or mechanical sanding.

The first method uses a benzyl alcohol-based stripper as an alternative to methylene chloride and N-Methylpyrrolidone (NMP)-based chemical strippers.

Be aware of the symptoms of acute overexposure via inhalation, which include difficulty concentrating, dizziness, fatigue, nausea, headaches, numbness, weakness, and irritation of the upper respiratory tract and eyes. If ignored, more severe consequences can include suffocation, loss of consciousness, coma, and death.

Methylene chloride is also metabolized by the body to carbon monoxide, potentially leading to carbon monoxide poisoning.

Acute exposure by inhalation can result in optic neuropathy and hepatitis. Prolonged skin contact can result in dissolving some of the fatty tissues in skin, resulting in skin irritation or chemical burns.