Activism has prompted more indepth research, increased acquisition and availability of EtO industry data, and increased focus on EtO as a carcinogen and toxin. This hazard was recognized fully by the EPA between 2016-2018 which led to increased assessment and acknowledgement of EtO as a toxin.
The main concern with EtO exposure includes inhalation. Laws that regulate air emissions have invariably affected and regulated this hazard. But specifically, below is a rough outline of laws that directly impacted the air emissions of facilities processing EtO:
Clean Air Act Section 112, Hazardous Air Pollutants. The CAA regulates Ethylene Oxide under section 112 of the CAA. The CAA labels EtO as a hazardous air pollutant. Under the CAA, EtO emissions can be regulated in conjunction with promoting the best emission controls.
Regulations on Sterilization Facilities (From Federal Register : National Emission Standards for Hazardous Air Pollutants: Ethylene Oxide Commercial Sterilization and Fumigation Operations)
Note, fugitive emissions have not been standardized by the EPA, including back vents, emergency ventilation etc.
Mainly stark contrast can be found between the EPA and various state and chemical manufacturing companies in terms of data divergence. The main concern surrounding EtO is the elevated cancer risk that occurs with long exposure both direct and indirect. The ways in which the EPA and other companies and agencies assess risk have been different in terms of unit quantity. The EPA utilized in 2016 the Integrated Risk Information System to model cancer risk. According to the American Chemical Council the, “ACC believes the value is significantly flawed.” Also, the Texas Commision on Environmental Quality has stated, “ ‘the US EPA unit risk factor (URF) for ethylene oxide is not scientifically justified.’ ”. This has led the TCEQ to raise its exposure limit from 1 ppb to 2.4 ppb.
Results of the Risk Assessment of Ethylene Oxide Emitting Facilities in Texas and Louisiana
Provides a list of 8 high risk EtO facilities both in LA and TX. Provides a breakdown of race in terms of proximity to facility and risk level. *One point to mention, is that data from the 2018 National Emissions Inventory (NEI), which was used, is provided to the EPA by the LDEQ and TCEQ.*
Ethylene Oxide Risk Map - Air Alliance Houston
Mapped by the Environmental Advocacy group Air Alliance Houston are EtO facilities across America. The top 25 EtO emitting facilities are labeled and census tracts with a cancer risk greater than 100 in 1 million are also highlighted.
The major organization involved in assessment of EtO is the EPA. The EPA and its branch leaders have spearheaded the response guidelines, have outlined cancer risks, and have conducted research in partnership with other national partners such as the NIH, federal departments of health, and state departments of health.
In the period between 1982 to 1984 multiple studies on lab rats concluded that inhalation concentrations of ethylene oxide could be correlated to cancer development. An analysis of the results found that increased exposure showed higher incidences of tumor development in both male and female lab rats. According to the EPA EtO is carcinogenic and, “Scientific evidence in humans indicates that exposure to EtO for many years increases the risk of cancers of the white blood cells, including non-Hodgkin lymphoma, myeloma, and lymphocytic leukemia. Studies also show that long-term exposure to EtO increases the risk of breast cancer in women.”
Ethylene oxide mainly becomes an environmental and health hazard in any community when it is released as a gas into the surrounding air. Ethylene oxide exposure includes inhalation and ingestion.
The map above constructed by air alliance Houston (Generated April 6, 2020) shows areas with EtO Cancer risk greater than 100/1 million as stars, top 25 EtO emitting facilities from 2008-2018 as red dots and other EtO facilities as black dots. Ethylene oxide facilities span the country mainly located on the east coast and gulf coast.
In a close up we can see Huntsman Petrochemical highlighted within the elevated EtO cancer risk.
Ethylene Oxide had been used as a fumigation insecticide to sterilize food, medical facilities and equipment. Currently ethylene oxide continues to be used and produced in the manufacturing processes of many commercial products, sterilizations, and insecticides. One of its major uses is as an intermediate in the production of ethylene glycol and other industrial chemicals. As noted by the CDC in the Toxicological review of ethylene glycol they note “in 1937, the direct oxidation of ethylene to ethylene oxide followed by hydrolysis to ethylene glycol”. Ethylene glycol is used in a variety of consumer products including paint, plastics, brake fluids, inks, cosmetics, etc. Ethylene glycol is additionally used to manufacture polyethylene terephthalate, used to produce disposable plastic bottles. The trickle down use of ethylene oxide in a series of additional manufacturing processes make it a valuable and versatile chemical in the production of a variety of consumer goods.
Ethylene oxide, as defined and according to the EPA, “Ethylene oxide is a flammable, colorless gas used to make other chemicals that are used in making a range of products, including antifreeze, textiles, plastics, detergents and adhesives. Ethylene oxide also is used to sterilize equipment and plastic devices that cannot be sterilized by steam, such as medical equipment.”
Photo Essay for Union Carbide Seadrift Plant.