68 Proceedings Summer 2025 CHEMICAL O F T H E Q UA R T E R Understanding Methyl Acrylate by lt Joe kolB Hazardous Materials Division U.S. Coast Guard Office of Design and Engineering Standards What is it? Methyl acrylate is a methyl ester, specifically of acrylic acid, with chemical formula C4H6O2. Characterized by an acrid odor, it is a colorless liquid under ambient conditions. Due to its tendency to polymerize, it is used in the production of synthetic fibers and plastics. It is also used to prepare adhesives, sealants, and amphoteric surfactants. Highly flammable, toxic, and car- cinogenic, methyl acrylate is considered a hazardous material in maritime transportation and is regulated by the U.S. Coast Guard and the International Maritime Organization (IMO). Why should I care? Synthetic Fibers The primary use for methyl acrylate is in the production of synthetic fibers. It is very notably copolymerized with acrylo- nitrile to produce acrylic and modacrylic fibers, which are then used to make clothing, carpets, and other home furnishings. Plastics The production of plastics is another major use for methyl acry- late. It is often copolymerized with other alkenes to give rise to specialized engineered plastics. Such plastics are commonly used in the manufacturing and medical industries and can be found in items like prostheses, contact lenses, and cosmetics. Flammability Concerns Readily ignited when exposed to heat, flame, or sparks, methyl acrylate poses a dangerous fire hazard. Its vapors can form dense, explosive air mixtures, which can travel considerable distances along the ground, risking flashback if they reach a source of ignition. Care must be taken when storing and working with methyl acrylate to avoid contact with sources of heat and ignition. Flammable vapor detection is required for maritime carriage. Health Concerns Methyl acrylate also demonstrates serious human health con- cerns, as it is highly toxic when inhaled, ingested, or absorbed by the skin as a monomer. Exposure may cause irritation of the eyes, skin, respiratory system, and gastrointestinal tract. Chronic exposure is associated with liver and kidney tissue damage. Special requirements, such as toxic vapor detection, personnel protection equipment, and increased ventilation, are required for maritime carriage. Polymerization Concerns Methyl acrylate readily polymerizes, and several precautions should be taken during maritime transportation. The Coast Guard and IMO require that it be protected against polym- erization via the addition of inhibitors, and ships must carry certificates attesting to such protections during transport. Cargo containment should be free of contaminants that could catalyze polymerization or degrade the inhibitor. Loading and carriage should be conducted as to avoid introducing heat to the methyl acrylate, which induces polymerization. Venting systems should be designed to avoid blockage from polymer buildup and be periodically checked for proper operation. What is the Coast Guard doing about it? The Coast Guard is responsible for enforcing maritime trans- portation requirements for all hazardous materials in liquid bulk, such as methyl acrylate. The Coast Guard Office of Design and Engineering Standards is responsible for creating and interpreting domestic regulations and voicing maritime trans- portation opinions on behalf of the United States at the IMO. About the Author: LT Joseph Kolb commissioned in the Coast Guard in 2015 through Offi- cer Candidate School and currently works in the Hazardous Materials Division at Headquarters in Washington, D.C. He graduated from the University of Virginia in 2009 with a B.S. in chemistry and The Ohio State University in 2021 with an M.S. in chemical engineering. References: CAMEO Chemicals, National Oceanic and Atmospheric Administration. https://cameochemicals.noaa.gov/chemical/1078. Visited 27 March 2025. International Maritime Organization. (2020). International Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in Bulk. IMO. PubChem, U.S. National Library of Medicine. https://pubchem.ncbi.nlm.nih. gov/compound/Methyl-acrylate. Visited 27 March 2025. United States of America. (2012). Title 46 Code of Federal Regulations: Shipping, Part 153 – Ships Carrying Bulk Liquid, Liquefied Gas, or Compressed Gas Hazardous Materials. Office of the Federal Register.
