19 Jun Biosafety Level Cleanrooms: A Quick Overview

Given the COVID-19 outbreak and its ramifications, it’s no secret that labs are important for studying and containing dangerous pathogens. But they also need to keep the outside world safe, too.

So whether you’re building a research lab, a pharmaceutical manufacturing facility, or need to meet biosafety regulations for some other purpose, it’s important to understand how cleanrooms and their related elements play a role in preventing biological contaminants from spreading and causing harm.

In this guide, we’ll cover what a biosafety level (BSL) cleanroom is, discuss the basics of biosafety levels (BSL-1 to BSL-4), and explore some of the design features of BSL environments.

What Is a Biosafety Level Cleanroom?

A biosafety level cleanroom is a controlled environment designed to handle specific biological agents, based on the requirements defined by biosafety levels (BSL-1 to BSL-4). These cleanrooms are made to protect researchers as well as the outside environment from dangerous microorganisms or other biological materials.

While standard cleanrooms typically focus on both viable (living) and non-viable (non-living) particles, biosafety level cleanrooms work to prevent biological hazards. The level of containment depends on the risk posed by the agents being handled.

The Four Biosafety Levels, Explained

As the biosafety level increases, so does the strictness of the lab, its containment features, and procedures/protocol. Here’s a breakdown of BSL-1 to BSL-4.

BSL-1

BSL-1 labs are the most basic type of biosafety environment. They are used for work on already well-understood organisms that don’t pose a significant health hazard to healthy adults, such as E. coli. A BSL-1 lab is typically separated from other areas of a facility. Work can be done on open benches, and in general staff follow basic practices like handwashing, wearing personal protective equipment (PPE), and disinfection after surfaces have been used.

Because the risk of infection is low and airborne transmission is not really a concern, BSL-1 does not usually require a cleanroom.

BSL-2

Furthermore, BSL-2 labs are designed for more moderate-risk agents that may cause illness in humans but are typically treatable. Some examples include Salmonella and Staphylococcus aureus. These spaces must be secured with self-closing doors and are equipped with biological safety cabinets (BSCs) where procedures take place. Staff must wear additional PPE, including face shields, and practice stricter protocols than BSL-1. A BSL-2 lab is not required to be a full on cleanroom, though some cleanroom elements may be used in their design.

BSL-3

Furthermore, BSL-3 labs are built for work with so-called “exotic” pathogens that can cause serious/fatal diseases, such as Mycobacterium tuberculosis, SARS-CoV-2, and West Nile virus. Greater restrictions are placed on these spaces, and so airflow is carefully controlled, negative pressure is used, and much stricter protocols and PPE are used (like respirators). BSL-3 labs, in some industries, may need to meet cleanroom standards.

BSL-4

BSL-4 cleanrooms are used for the highest-risk pathogens, like Ebola, that can be spread by airborne transmission, and especially those that do not have treatments and are frequently fatal. These labs have to be fully isolated, use special air systems, and require workers to wear full-body, positive-pressure suits. Entry and exit involve strict protocols, including chemical showers, and all air and waste are filtered or neutralized. Unlike lower biosafety levels, BSL-4 labs are typically designed as cleanrooms to control the environment.

Design Features of BSL Cleanrooms

BSL cleanrooms are built to help meet the requirements of each specific biosafety level, from BSL-1 to BSL-4. Of course, the higher the level, the more features and environmental controls will be required. Here are a few of their most important design features:

Surfaces and Construction

• Walls and flooring are made of seamless, non-porous materials that are easy to clean and resist chemicals.
• Walls and ceilings often have hidden seams and rounded corners (called coving) to make cleaning easier, and to prevent any crevices where microorganisms can gather or accumulate.

Doors and Entry Systems

• Doors must be airtight, especially for BSL-3/BSL-4 spaces, and are often equipped with maglocks or inflatable seals to control access.
• Doors may also close automatically and be part of an interlocking system to help keep air pressure, whether positive or negative, at the right levels.

Air Handling and Filtration

• Air flows in a controlled direction, typically from clean to less clean zones; unidirectional/laminar airflow may also be employed.
• Depending on the BSL, the system supports 15 to 60 air changes per hour (ACPH).
• HEPA and/or ULPA filters are used to catch particles.

The Bottom Line

Biosafety level cleanrooms are an important part of keeping people, products, and the environment safe when dealing with potential biohazards. The higher the biosafety level, the more strict the space (and therefore the design) will need to be. Whether you’re planning on building a lab build or manufacturing facility, understanding these requirements is an important part of keeping people safe.

Interested in setting up a biosafety level cleanroom at your location? Reach out to the experts at Allied Cleanrooms for a quote on new controlled environments today.

FAQs About Biosafety Level Cleanrooms

1. Can a cleanroom be upgraded to meet a higher biosafety level?

In some cases, yes, especially if the building is modular. Modular cleanrooms can be reconfigured or expanded much more easily than traditional structures. Upgrading to a higher biosafety level will still, however, likely require significant changes to HVAC systems and more.

2. Do biosafety level cleanrooms need to follow ISO classifications?

It will depend on the exact application/industry, but not always. ISO classifications (like ISO 7 or ISO 8) are used to measure particle cleanliness, but BSL cleanrooms focus on containment of biological material.

3. Can biosafety cleanrooms be built in existing buildings?

Yes, they can, but that will depend on which biosafety level you’re trying to meet. With modular construction, it’s possible to add cleanroom space to an existing facility, though for BSL-4 this is probably not feasible.