Successfully Handling Ethylene Oxide, A Dangerous but Integral Material

By OPW | Sep 18, 2019

The dichotomy that is at the root of many industrial-manufacturing processes is this: hazardous materials are needed in order to produce something very useful.

One of these potentially hazardous, but important, materials is ethylene oxide (EtO), which is a flammable, colorless gas that smells like ether when it is at toxic levels. In addition to being flammable and highly reactive, acute exposure to EtO can lead to physical and health hazards, such as respiratory irritation and lung injury. Prolonged exposure can cause long-term effects like cancer.

In other words, EtO is a substance that needs to be handled with extreme care at all times, with the Occupational Safety and Health Administration (OSHA) putting its exposure limit at one part per one million parts of air as measured over an eight-hour time-weighted average.

Despite its risks, without EtO we would not have such materials as ethylene glycol, which is the main ingredient in automobile antifreeze/coolant, or any number of important solvents, adhesives, detergents, textiles, foams and pharmaceuticals.

So, with EtO being necessary in many industrial-manufacturing processes, it is imperative that it be securely contained to minimize leaks that can be harmful to people, surrounding communities or the environment. A large portion of the responsibility for the safe, leak-free handling, transport and delivery of EtO falls on the shoulders of the railroads that are a pivotal link in its supply chain.

Recognizing the importance of preventing the release of EtO during railway accidents or through non-accidental release (NAR) incidents, Midland Manufacturing, Inc., has developed an Ethylene Oxide Enhanced Fittings Package that can help guarantee reduced-risk handling, transport and delivery of EtO. The equipment in this fittings package includes:

  • Angle Valve/Check Valve Combination: Combines an angle valve with a spring-loaded check valve with all primary seals located below the surface of the pressure plate. This helps reduce the risk of product loss in the event of catastrophic damage to the angle valve.
  • Low-Profile Pressure Relief Valve (PRV): Designed to extend less than three inches above the pressure plate. This reduces the chance that the PRV will be sheared off during a rollover incident. The PRV is also equipped with two protective O-rings and top/bottom stem guides, which help minimize the chance that a NAR will occur.

Because no EtO-dedicated railcar fleet is homogeneous, there can be no “one size fits all” solution to outfitting it. Therefore, Midland works with each customer individually to build the best EtO-handling package. The goal is to develop a package that delivers the best in railcar uptime, personnel utilization, bottom-line optimization, safety and peace of mind for the railroad operator, rail personnel, end user and the population in general.

For more information on Midland Manufacturing, Inc, and its complete portfolio of tank railcar products, please visit