Methylene chloride has been under strict scrutiny and testing to determine whether it poses an unreasonable risk to human health and safety. The commonly used chemical had already been banned in some consumer products before the Environmental Protection Agency (EPA) recently took further action. The limited ban on methylene chloride by the EPA has left several industries wondering how, and if, it impacts their products and processes going forward.

Manufacturers of pharmaceuticals and researchers have been asking: Does the methylene chloride ban apply to laboratory use? And, if so, how can labs prepare for the methylene chloride ban?

While some sectors must retire the use of the hazardous material, others are tasked with implementing a plan of action that involves protective clothing for methylene chloride, sufficient air quality testing, and ventilation. If you are concerned about methylene chloride exposure or how to navigate the ban, follow along for more information.

What is Methylene Chloride?

The United States produces and imports more than 130,000 tons of Methylene Chloride annually, according to the EPA. Sometimes referred to as dichloromethane, DCM, or MC, methylene chloride is a volatile, colorless liquid with a sweet aroma.

Widely used in paint removers and pharmaceutical manufacturing, the substance has been linked to a variety of health conditions and fatalities. Despite being a known health risk, the chemical has been routinely used in the following.

  • Paint Strippers & Aerosols
  • Adhesives & Glues
  • Cleaning Fluids & De-greasers
  • Pesticides for Strawberries and Grains
  • Warehouse Pesticide for Cereals, Flours, and Tobacco Leaves
  • Decaffeinated Coffee
  • De-Greening Citrus Fruits
  • Spice & Hops Extracts

 

With its low boiling point and ability to de-grease and cleanse surfaces, methylene chloride became a popular agent in laboratories. Until the recent EPA ban, it was regularly used in synthesis, extraction, and purification processes. The most common way it places workers at risk is through inhalation.

What are the Health & Safety Risks Associated with Methylene Chloride?

The solvent has wide-reaching industry uses, thereby exposing workers in a variety of occupations. People who perform tasks such as paint stripping, making polyurethane foam, de-greasing machinery, metal cleaning, applying it as a pesticide, or sanitizing spaces are most likely to inhale the fumes or have the liquid splash on their extremities.

It’s important to always wear personal protective clothing and a face mask or respirator together so both liquid and vapor hazards are mitigated. These are early warning signs of methylene chloride exposure.

  • Dizziness, Drowsiness & Headaches
  • Vision Impairments
  • Nausea & Vomiting
  • Reduced Motor Functions
  • Difficulty Hearing
  • Burning Sensation from Direct Contact
  • Cognitive Impairment (Confusion)

 

When handling methylene chlorine, it’s essential for professionals to keep in mind that it can enter the body through the lungs or be absorbed through skin contact. Once it enters the body, it undergoes a dangerous transformation. Methylene chloride metabolizes into formaldehyde and carbon monoxide.

Minor exposure can result in skin and internal irritation. Significant exposure can lead to choking and death. As carbon monoxide, the body quickly suffers from oxygen deficiency.

Methylene chloride has been on the radar of health and safety organizations because of its link to lung, liver, and bone cancer. Research indicates that regular, long-term exposure increases the risk of cardiovascular conditions, as well as damage to the central nervous system and liver.

Why is the EPA Banning Methylene Chloride?

One might anticipate agencies such as the EPA, Food & Drug Administration, Centers for Disease Control & Prevention (CDC), and the Occupational Safety & Health Administration (OSHA) to have quickly sidelined methylene chloride because it poses a health risk. Truth be told, health and safety agencies seem to strike a balance.

For instance, at least one type of asbestos was still being used in the U.S. until earlier this year. Organizations such as the CDC and OSHA create regulations regarding health hazards such as crystalline silica, rather than ban industrial and commercial processes associated with them.

It may sound counterintuitive, but the National Institute of Health (NIH) established permissible limits of methylene chloride in food and beverages. Workers can also be exposed to 25 ppm of methylene chloride averaged over an 8-hour shift. However, the EPA banned most uses due to its ability to penetrate non-protective clothing and subpar breathable masks, leading to the following.

  • Impact on the Brain: Methylene chloride tends to impact the brain in a similar fashion to alcohol. People who are exposed become clumsy, increasing the risk of a workplace injury or fatality. Long-term exposure can result in chronic fatigue, sleeplessness, memory loss, personality changes, and depression.
  • Nervous System: Repeated exposure may result in long-term or permanent damage to the nervous system. Excessive exposure can lead to poor coordination.
  • Skin Contact:Too often, the solvent soaks unprotected shoes and street clothes. As it wets the skin, workers usually experience a burning sensation. The substance is also easily absorbed, putting a worker’s internal health at risk.
  • Eyes, Nose & Throat: Although airborne methylene chloride irritates the nose and throat, it can permanently damage vision if splashed into the eyes.

Because methylene chloride transitions into carbon monoxide, it exacerbates lung, heart, and other organ conditions. Inhaling it might be considered akin to someone with lung cancer smoking cigarettes. These factors, coupled with the fact the substance has proven difficult to protect against, appear to have led the EPA to implement a limited ban.

What Does the Ban Entail?

Congress revised the 2016 Toxic Substances Control Act in an effort to empower the EPA to curtail the use of chemicals that pose “an unreasonable risk to human health or the environment.” Methylene chloride was recently added to the list after 85 people died.

Unlike the U.S. recently joining 50 other countries to ban asbestos, the EPA is reportedly rolling out a ban in most industrial settings, as well as more stringent workplace limits and protection in others. The FDA has not yet eliminated methylene chloride from pesticide use, food storage, or decaf coffee, among others.

The most impactful aspect of the ban, in terms of mass exposure, stems from the EPA’s choosing to eliminate industrial stripping processes, as well as commercial and consumer products. The EPA reportedly banned the agent from paint thinners five years ago.

Does the Methylene Chloride Ban Apply to Laboratory Use?

The short answer is: No. Laboratories that plan on using methylene chloride are tasked with implementing a Workplace Chemical Protection Program to bring its usage within the EPA’s guidelines.

The use of methylene chloride also requires employers to install a commercial ventilation system and provide personal protective clothing and equipment. Other exemptions include the following.

  • Electric Vehicle Battery Manufacturing
  • Production of Chemicals that Reduce Carbon Footprints
  • Military and National Security Needs

 

NASA has been given a 10-year exemption that applies only if the agency does not have access to a suitable alternative.

How Can Labs Prepare for the Methylene Chloride Ban?

The EPA’s expectations for laboratory use include implementing "engineering controls such as fume hoods” to minimize human exposure. Companies are required to monitor airborne toxicity levels and deploy personnel protective equipment and clothing that prevents seepage and respiratory protection to filter out gases.

The PPE and disposable protective clothing for methylene chloride include the following.

 

Safety administrators at laboratories would also be well-served to establish spaces for staff members to don and doff disposable protective clothing. Having a designated area to strip off and properly discard used items helps reduce the risk of cross-contamination.

It’s also important to maintain an inventory of disposable protective clothing that can be accessorized to increase protection levels for certain tasks/ as needed.