Sample Quality| Industrial hygiene & Environment | Safety

Liquid and Gas Sampling  

Ethylene Oxide Sampling (EO, EtO, C2H4O) Project

The extensive knowledge and experience our team at Biar Inc. possess, allows us to provide comprehensive solutions for the sampling of extremely hazardous substances. Ethylene oxide is an ether compound that is used to produce a variety of chemicals including detergents, thickeners, and solvents. As with many types of ether, ethylene oxide has an anesthetic effect and is present in gaseous form at standard atmospheric conditions, making it extremely hazardous. In addition to rendering a person unconscious in sufficient concentrations, it is also flammable, carcinogenic, mutagenic, and causes severe irritation to human tissue. When heated, ethylene oxide also expands rapidly causing explosions and fire. Due to its toxicity and volatile nature, no exposure of ethylene oxide is allowed during sampling and the sampling vessel must be designed in such a way to accommodate the expansion of the compound upon exit from the processing stream.

To meet these sampling challenges, we designed a multi-function stainless steel valve with a bellows type seal, stuffing box, leak detection port, Magic Hand Wheel, and safety plug that is used with a bayonet adapter connection. Bellows type seals are chosen when the risk of stem leakage must be kept to a minimum; this type of seal also offers several maintenance advantages over other seal options. The leak detection port provides a means of determining any issues with the bellow before a leak occurs, while the stuffing box acts as a secondary containment device should there be an issue with the bellows during the sampling process. The safety plug provides secondary containment when the valve is not in use and prevents any exposure if an operator inadvertently opens the valve when the sampling vessel is not connected.

Our Magic Hand Wheel design is a spring to close hand wheel actuator that acts as an added security measure to prevent exposure should the operator’s hand slip off of the valve during sampling. The bayonet adapter easily connects the sampling cylinder to the sampling valve. There are two sampling vessel options for ethylene oxide sampling: a container with a dip tube, or a piston-injector with expansion ring. In the first option, the drip tube provides room for expansion, preventing overpressure when the ethylene oxide enters the container. This set-up is simple, contains no moving parts, and is therefore very safe with minimal maintenance required. The primary drawback with this option is that thoroughly emptying the container can be somewhat difficult, making cleaning a challenge.

In the piston-injector with expansion ring sampling set-up, a spring is fitted behind the piston to allow expansion of the ethylene oxide as the temperature increases. Thoroughly emptying and cleaning the container is easy using this set-up. However, because there are moving parts involved, the risk of leakage is increased, and there is appreciably more maintenance required. The container with drip tube option also has a higher pressure rating than the piston-injector with expansion ring design. The optimal sampling vessel is ultimately determined by the sampling conditions and customer preference.

Both the sampling valve and the collection container are designed with absolutely no dead space to prevent any entrapment of the ethylene oxide gas that could lead to accidental exposure. This is a critical aspect of our valve designs, as many competitors are unable to achieve this standard of quality. All of our valves are designed to meet and exceed all government safety standards for the given application, and we have been recognized by numerous chemical manufacturers for our innovative hazardous material sampling solutions. For additional information about our ethylene oxide sampling valves and vessel options, contact us directly.

Comparison of the Two Recommended Sample Cylinders

  Advantages Inconveniences
Piston-injector with expansion spring
  • Easy to empty
  • Easy to clean
  • Easier to work with
  • Moving parts:
    • More maintenance required
    • Increases leak risks
  • Lower pressure rating
Container with dip-tube
  • No moving parts:
    • Less maintenance required
    • Reduces leak risks
  • Higher pressure rating
  • Safer to work with
  • Difficult to empty it thoroughly
  • Difficult to clean