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Published: June, 2013; Vol 10, Num 1

 

Minimize the Risks of Methylene Chloride

Alternate description

LHSFNA Management
Co-Chairman
Noel C. Borck

"Laborers understand that confined spaces can be dangerous," says LHSFNA Management Co-Chairman Noel C. Borck, noting that poor ventilation in confined spaces kills six construction workers every year. Among these were 14 bathtub refinishers killed since 2000 while using products containing methylene chloride (dichloromethane or DCM).

"The problem with methylene chloride is so serious that OSHA has issued a Hazard Alert for bathtub refinishers, but the solvent is used in many renovation projects so employers and workers in all of the building trades should take heed," says Borck.

Heavier than air, DCM vapors can fill a bathtub and, eventually, the lower levels of an enclosed bathroom. If inhaled in sufficient quantities, they form carbon monoxide in the blood, inhibiting the body's ability to transport oxygen. Victims suffocate.

Whenever possible, alternatives to methylene chloride – benzyl alcohol based strippers or sanding, for example – should be used. If options are not available, engineering and work practice controls and PPE can reduce the risk of exposure, serious injury and death.

Methylene chloride

Methylene chloride is found in many remodeling products including paint strippers, metal cleaners and degreasers. It is also an ingredient in a number of aerosols, pesticides, spray paints and some household products such as spray shoe polish, spot removers and water repellants. Workers and consumers are exposed when they inhale the vapors, when they absorb it through their skin or when it gets in their eyes.

Methylene chloride has a sweet odor. If you can smell it, you are being overexposed. However, since the body can quickly become desensitized to the scent, you can be overexposed to methylene chloride and not even be aware.

Health effects of methylene chloride:

  • Inhalation: Headache, nausea, dizziness, confusion, drowsiness, loss of consciousness, death
  • Skin Contact: Pain, redness, swelling
  • Eye Contact: Sore, red eyes, tearing
  • Ingestion: Burned lips, tongue, throat, stomach
  • Long-Term (Chronic) Exposure: Dry, red, cracked skin, harm to liver and nervous system, aggravation of existing heart conditions, increased risk of cancer

Hazards of bathtub refinishing

Bathrooms are often enclosed places with little ventilation. This makes using methylene chloride when refinishing bathtubs especially hazardous. Whether sprayed, brushed or poured, methylene chloride vapors can quickly build up in the tub where the worker is working. It does not take much to kill. Death has resulted from being exposed to as little as six ounces.

Engineering controls for methylene chloride:

  • OSHA requires that employers test for methylene chloride and to train and protect workers exposed to its hazards.
  • Do not allow the product to accumulate in the air in work or storage areas or in confined spaces.
  • Use a local exhaust ventilation and enclosure, if necessary, to control amounts in the air. Room fans and open windows are not sufficient.

Work practice controls:

  • Avoid use of methylene chloride or minimize the amount of methylene chloride used at each site.
  • Avoid or minimize spraying methylene chloride.
  • Follow good housekeeping measures, including spill and leak control and appropriate personal hygiene practices (such as making skin washing areas available to workers).
  • Use long-handled tools (e.g., scrapers, brushes) to avoid leaning into the bathtub.
  • Leave the room immediately after applying the methylene chloride-based stripping agent to limit exposure to vapors. Use full-face supplied-air respirators, goggles and face shields, protective gloves made of polyethylene (PE)/ethylene vinyl alcohol (EVOH) or other materials that are resistant to methylene chloride (contact the glove manufacturer for recommendations) and other appropriate personal protective equipment (PPE) that is resistant to methylene chloride during the refinishing process.

"Although risk of exposure is significantly reduced when controls are implemented, the threat can never be entirely removed," says Borck. "Rather than the first choice, methylene chloride-based products should always be one of last resort."

Online Resources:

Preventing Worker Deaths from Paint Strippers Containing Methylene Chloride (Cal-OSHA)

Paint Stripping Products: Safer, Less Toxic Choices (Cal-OSHA)

Successful Bathtub Stripping using Sanding as an Alternative to Methylene Chloride (WA State Dept of Labor and Industries)

Successful Bathtub Stripping with Benzyl Alcohol as an Alternative to Methylene Chloride (MC) (WA State Dept of Labor and Industries)

[Janet Lubman Rathner]