A Limit That Is About to Disappear
From 1 December 2026, Australia will remove the numerical workplace exposure limit for ethylene oxide, along with a list of other non-threshold genotoxic carcinogens. The duty does not vanish with the number. Employers must eliminate the use where practicable, substitute another sterilisation modality where they can, and otherwise demonstrate that exposure is minimised as far as reasonably practicable.
Other jurisdictions still publish numbers, but the direction of travel is the same. A sterilisation plant that can only show it stayed under a figure will struggle to show it controlled the hazard. That argument is built from engineering records, monitoring and material data.
Nitrile Is the Wrong Default
Ethylene oxide is handled as a liquid under pressure in cylinders and supply lines, and it boils at about 10.7 °C. Guidance from occupational safety bodies is consistent on materials: butyl rubber gives the best permeation resistance, with Viton and PE/EVAL laminates among the alternatives. Nitrile, the glove that is everywhere in a hospital, is not adequate against liquid ethylene oxide - a fact that catches out facilities where the same box of gloves serves the ward and the steriliser room.
The distinction buyers miss is phase. A glove can pass a liquid test and still be a poor vapour barrier, because method, concentration and temperature differ. Specifications should name the substance, the phase, the expected concentration and the task duration, and should ask for the underlying test report rather than a pictogram. Where a cylinder change takes seconds and an aeration-room adjustment takes half an hour, one glove will not cover both.
Cold Burns Arrive With the Chemistry
Liquid ethylene oxide leaving a pressurised line flashes violently, adding frostbite to a chemical burn that may blister hours later. Gloves for cylinder work therefore need cold performance as well as chemical resistance, and cuffs must be long enough to cover the wrist when both arms reach into a manifold.
Boots belong in the same specification. Cylinder rooms and abator areas present a spill surface, a flammable atmosphere - the flammable range of ethylene oxide is exceptionally wide - and a static ignition risk that argues for antistatic footwear under EN ISO 20345. Leather is the wrong material in this room: it absorbs and holds the liquid against the skin. Doffing matters as much as donning: a boot the operator can step out of without touching the outer surface beats a better barrier that traps the wearer.
Where the Exposure Actually Sits
Surveys of steriliser operations have long shown that the dose is concentrated in a few minutes: door-open at the end of a cycle, the transfer of an unaerated load, cartridge puncture, cylinder disconnection, and maintenance inside the chamber and ductwork. Chamber entry is a confined-space operation, requiring testing, a permit and a standby attendant before anyone thinks about gloves.
That pattern should drive procurement: rather than one glove for everyone with room access, map the tasks and specify three - a thin butyl or laminate for load handling, a heavier unsupported butyl for cylinder and manifold work, and a cut-resistant outer for chamber and duct maintenance. Add a written change rule - after every cylinder change, and at each shift end for load handlers - and the specification starts to look like a control rather than a purchase order.
Three questions for any supplier: which material and thickness is being claimed, against which test method and challenge phase, and what evidence supports the replacement interval the plant actually works to. A sterilant with no safe exposure level deserves better than a glove chosen by habit.