Sterilization

For most of the country it was a long, hot summer. Too long and too hot for many regions that have experienced record setting temperatures and drought conditions. So, the Safety Guys thought it would be a fine time to discuss one of our hot topics (no groans from the gallery please)— autoclaves.

Like the coffee pot used for brewing your favorite morning beverage, autoclaves are such a common and familiar piece of lab equipment that it is easy to overlook the associated hazards. And, if we continue to not think about what might go wrong, sooner or later we will get burned (alright, no more bad puns). But, by following our simple three step program of training, testing/monitoring/maintenance, and recordkeeping, you can avoid mishaps and potential significant damage or injury.

Recognizing the Hazards
Seriously, consider autoclaves as large specialized pressure cookers. Autoclaves use heat and pressure with water to create superheated steam. As such, they can pose significant hazards to untrained or lackadaisical employees.

Autoclaves are usually needed for two basic purposes, either to steam-sterilize media, instruments, or lab equipment such as glassware and surgical implements, or to inactivate biological waste materials.¹ The main hazards are physical ones presented by high temperatures, steam, and pressure. Effective sterilization requires steam temperatures in excess of 250 °F (121 °C). Typical autoclave pressurization is at least 20 pounds per square inch (psi). Depending on the use, additional biological hazards such as infectious materials or physical hazards from sharps may be of concern. By utilizing the practical information and guidance given here (as well as from many other sources online) researchers are ensured safe operation of autoclaves in the laboratory.

Training is the First Step
Even though loading and running an autoclave may seem as simple as using your dishwasher at home, some forethought is required to operate the autoclave safety and efficiently. Begin by becoming thoroughly familiar with the owner/operators manual for your particular machine.

Controls vary between brands and each has its own unique loading characteristics, load sizing requirements, cycle settings, and cycle types.² The amount and type of materials requiring sterilization or inactivation/decontamination will determine the cycle needed. It is highly recommended that the manufacturer’s operation manual be copied (perhaps even water-proofed/laminated) and a copy kept in the room with the autoclave.

Instill a policy were all users are trained prior to operating any autoclave. Principle investigators or laboratory supervisors should bear the responsibility of insuring this is done. Document all training and maintain copies of the records in the lab.

At a minimum training should cover:

• Location, function, and use of controls
• Proper loading and unloading (including packaging, sizing, and testing protocols)
• Required personal protective equipment (heat resistant gloves, lab coats, eye protection, and closed-toed shoes)
• Incident and maintenance reporting; recordkeeping
• Emergency procedures