In brief
In a central sterilisation unit, risks vary by area: sharp instruments and biological contamination in the soiled area, disinfectant vapour in the washing area, autoclave pressure, steam and hot loads in the sterilisation area, and ethylene oxide in low-temperature methods. This article explains the hazards of each area, periodic inspection of the autoclave and the order of measures for working with carcinogenic gases.
Sterilisation unit safety: from the soiled area to the sterile store
A central sterilisation unit is a line in which soiled instruments coming from operating theatres and wards are washed, packed and made sterile again. Sterilisation unit safety meets a different hazard in each part of this line. In the same shift, a worker may come into contact with sharp points on soiled instruments, disinfectant vapour in front of the washing machine and hot steam at the autoclave door.
| Area | Main hazard | Example measure |
|---|---|---|
| Reception and soiled area | Sharp instruments, blood and body fluids, carrying heavy sets | Closed transport containers, sharps bins, gloves and face shield, transport trolley |
| Washing and disinfection | Disinfectant vapour and splashes, hot water | Enclosed washer-disinfector, local exhaust ventilation, eye protection |
| Packing | Repetitive movement, prolonged standing | Adjustable table, task rotation |
| Sterilisation | Autoclave pressure, steam, hot loads, ethylene oxide | Periodic inspection, door interlock, cooling time, closed system and gas detection |
| Sterile store | Reaching on racks, stacking | Placing heavy sets at waist height, step stool |
Physically separating the areas matters not only for sterilisation quality but also for worker safety: the biological and sharps risks of the soiled area are not carried into the clean area.
Autoclave safety: pressure, steam and the door
A steam autoclave is a vessel operating under pressure. Annex III of the Regulation on Health and Safety Requirements for the Use of Work Equipment lists the autoclave among equipment subject to periodic inspection: unless a shorter period is specified in the standards, the inspection is carried out once a year and in accordance with the criteria in the TS EN 285+A1 and TS EN 13060+A1 standards. Under the same regulation, the person who maintains the equipment cannot carry out its periodic inspection.
Between annual inspections, the following points are watched in day-to-day operation:
- Door: The door must not open before the cycle has finished and the internal pressure has fallen to a safe level. This function of the door interlock is tested regularly; the device is not operated with a faulty interlock.
- Seal and leaks: Wear on the door seal and steam escaping from the edge of the door during the cycle are entered in the maintenance record.
- Safety valve and gauges: Pressure and temperature gauges must be readable, and the safety valve must not be obstructed.
- Warnings: Alarms given by the device are not silenced on the assumption that "it will pass anyway"; the alarm instructions are posted next to the device.
- Training: Only workers who have received training in its use operate the autoclave.
For the general rules on pressure vessels, see our article on pressure vessels and compressor tanks, and for the wording in inspection reports, our article on how to read a periodic inspection report.
Sterilisation burns: hot loads, steam and condensate
Sterilisation burns mostly happen after the cycle has finished. When the door is opened, rising steam reaches the face and arms; the rack trolley and metal containers stay hot enough to burn for some time; condensate collected inside a set can spill during carrying.
Measures:
- The face is not held level with the door when it is opened; the door is opened slightly and the steam is allowed to disperse.
- The load is not handled until the cooling time set by the manufacturer and the unit has passed.
- Heat-resistant gloves are used for hot racks and containers; when pushing a hot loading trolley, the arms are kept away from the body.
- The floor in front of the door may remain slippery because of condensate; non-slip footwear is worn and the floor is kept dry.
For first response steps, see our article on burn first aid in the workplace.
Ethylene oxide exposure: working with a carcinogenic gas
Ethylene oxide, used to sterilise heat-sensitive instruments, is a gas classified as both flammable and carcinogenic and mutagenic. Ethylene oxide exposure cannot be detected by smell; at low levels it may give no warning. Measures are therefore set up in the order of the Regulation on Health and Safety Measures for Work with Carcinogens or Mutagens:
- Substitution (Art. 6): Where technically possible, it is assessed whether the instrument can be sterilised by a less hazardous method. Low-temperature methods such as hydrogen peroxide are the subject of this assessment.
- Closed system (Art. 7): The ethylene oxide steriliser and the aeration section operate as a closed system; the load is not removed before the aeration time has passed.
- Early warning (Art. 7): The regulation requires suitable measurement systems for the early detection of an unexpected release of the carcinogen into the environment. Continuous gas detection and alarms in the steriliser room meet this provision.
- Organisation: Access to the room is limited to authorised persons, the room is marked with warning signs and eating and drinking are prohibited there. Gas cartridges are stored according to the manufacturer's instructions and in line with the rules for flammable substances.
- Records (Art. 14 and 17): A list of workers who may be exposed to ethylene oxide and exposure records are kept; these records and health surveillance records are kept for at least 40 years after exposure ends.
We plan workplace exposure measurements with accredited laboratories and enter the results into the risk assessment.
Disinfectant vapour: washing and high-level disinfection
Detergents used in manual pre-cleaning, high-level disinfectants and the chemicals used in some low-temperature sterilisation methods can irritate the eyes, skin and respiratory tract. Disinfectant vapour is released most when instruments are soaked in open containers, during manual mixing and during dilution with hot water.
The order of measures in Art. 7 of the Regulation on Health and Safety Measures for Work with Chemical Agents also applies here: first a less hazardous product, then engineering measures such as closed systems and ventilation, and finally personal protection. In practice this means:
- Instruments that can be are processed in enclosed washer-disinfectors.
- The lids of sinks and soaking containers used for manual processing are kept closed, and local exhaust ventilation is provided in the area.
- The product is diluted at the ratio in the safety data sheet and in labelled containers.
- Eye and face protection and gloves suitable for the product are used; an eyewash station is within reach.
Annex 1 of the regulation gives an 8-hour limit value of 1 ppm (1.4 mg/m³) for hydrogen peroxide. In units using hydrogen peroxide systems, the measurement plan is drawn up taking this value into account. For the general framework of the regulation, see our article on the chemical agents regulation.
Carrying soiled instruments: sharps, biological agents and weight
Carrying soiled instruments from the operating theatre to the unit is the stage where sharp points and biological contamination are most often overlooked. Art. 17 of the Regulation on the Prevention of Risks from Exposure to Biological Agents requires the uncertainty about biological agents in patient samples and materials in human healthcare workplaces to be taken into account particularly in the risk assessment.
Rules for transport and reception:
- Sharps waste and disposable blades are separated at the point of use in the operating theatre; they are not left in the set.
- Soiled sets are carried in closed, leak-proof transport containers, using the soiled lift or soiled corridor.
- When sets are opened in the soiled area, instruments are not picked up one by one by hand; they are processed together with the set basket.
- Heavy sets are kept at waist height, and rack and table heights are arranged accordingly.
We explain what to do in needlestick and cut injuries in our article on sharps injuries, and the risk groups in our article on biological agents and risk groups. For materials contaminated with antineoplastic drugs, see our article on exposure in antineoplastic drug preparation.
When carrying out risk assessments at hospitals and surgical centres in Bursa and the surrounding provinces, we observe the sterilisation unit area by area and link the autoclave's periodic inspection schedule to the periodic inspection plan. Other topics specific to healthcare facilities are on our healthcare facilities sector page.
Frequently Asked Questions
How often is autoclave periodic inspection carried out?
Under Annex III of the Work Equipment Regulation, once a year unless a shorter period is specified in the standards. The inspection is carried out by persons authorised to carry out periodic inspections according to the criteria in the TS EN 285+A1 and TS EN 13060+A1 standards.
What measures are mandatory in a room with an ethylene oxide steriliser?
The Carcinogens or Mutagens Regulation requires a closed system, minimising the number of workers exposed, marking the area, a measurement system for early detection of unexpected releases and keeping exposure records. The records are kept for at least 40 years.
Why must the autoclave door not be opened before the cycle has finished?
During the cycle, the chamber is filled with hot steam under pressure. Opening the door early can cause serious steam burns and the door being thrown open by the pressure. This is why the door interlock is tested regularly.
What PPE should sterilisation unit workers use?
It varies by area: a fluid-resistant gown, gloves and face shield in the soiled area; chemical-resistant gloves and eye protection in the washing area; heat-resistant gloves and non-slip footwear in the sterilisation area. The selection is made according to the risk assessment.
A risk assessment that identifies and scores hazards on site, links each measure to an owner and a date, and has a clear renewal schedule.
Bursa SİSTEMER OSGB Technical Team — written from the field experience of our OHS specialists and workplace physicians. Legal information is valid as of the publication/update date; contact us for an assessment specific to your business.