Creating Consistent Standards for Lab Autoclaves and Sterilizers
By: Priorclave North America
Category: Lab Practices
Given the state of the climate crisis, there’s increasing urgency to reform how we approach research and development. As it stands, the annual carbon emissions from the biotech/pharma sector alone are nearly twice that of Nigeria (home to more than 211 million people). But it’s extremely hard for labs to reign in their environmental impact when they have no way to compare resource consumption among similar pieces of critical equipment. (e.g., fume hoods, freezers, lab autoclaves and sterilizers, centrifuges, and so on.)
In 2021, the US Department of Energy National Renewable Energy Lab chose My Green Lab (a non-profit organization dedicated to building “a global culture of sustainability in science”) to help create standards for measuring and disclosing the environmental impact of lab equipment.
As a first step, My Green Lab has teamed up with the California Energy Commission & California Plug Load Research Center and a variety of lab research industry leaders to create a set of standards to form the basis for how autoclaves and sterilizers are evaluated within My Green Lab’s ACT Program (the premier eco-label for laboratory products).
Environmental Impact Standards for Lab Autoclaves and Sterilizers
The current draft standard focuses on the most common style of research lab autoclave:
- A 200 to 1000 liter front-loading steam autoclave equipped with vacuum pump, post-cycle cooling of some sort, and “tempering water”
(“Tempering water” refers to a cold water line dedicated to reducing the effluent waste water temperature to below 140°F/60°C. This is required by many building codes to protect PVC drain lines and lower the risk of injury to building occupants in the case of a malfunction or accident.)
The tested autoclave may also include features like steam jackets, air-ballast systems, and energy saving hibernation systems if these are standard on that particular model.
In order to verify their autoclave’s resource consumption, manufacturers will outfit it with a third-party data monitoring device. This will track power use, water use, and cycle count at 30 second intervals. Manufacturers will run a set of predetermined cycles while monitoring the autoclave for a full 24 hours. Those numbers will form the basis for that sterilizer’s reported environmental impact.
Capturing a True Picture of Lab Autoclave and Sterilizer Resource Use
Importantly, the standard requires the manufacturers to collect a full 24 hours of data. That’s the case even if running a given set of use cases can take as little as six to eight hours. This is extremely important. As we’ve often noted in the past, the water and energy an autoclave or sterilizer uses while running a cycle are often just half the story—literally.
For example, with some very common autoclave configurations up to half of the power and water the unit consumes is used while it is sitting idle. This is because those configurations rely on features (such as steam jackets) that must idle hot and require a constant flow of tempering water. That adds up. In one notable (but far from exceptional) case, the University of California at Riverside discovered that during a 39-day period during which their research sterilizers sat entirely unused, the autoclaves still consumed almost 16,000 gallons of water.
Priorclave North America CEO Barbra Wells believes that My Green Lab’s work thus far has produced a balanced and insightful set of standards:
“I like how these make allowances for the wide range of sterilizer equipment people use, while also stipulating a set of requirements that really allow the end-user to honestly assess the impacts that equipment will have. For example, many labs use autoclaves with steam jackets. In some of those labs, the capabilities that come with that jacket are very important. They really need quick warm-up on-demand sterilization, or fast post-cycle cooling, or very dry loads. It’s worth the high power and water demands for them. But in many labs, these are features they rarely if ever use. But still, they’re wasting thousands of gallons of fresh water every day to have that feature.”