When lab managers need to work with contagious and deadly pathogens, they need a safe and clean environment. Biosafety cabinets are an excellent Lab equipment because they offer various amenities while keeping both the human being and the surrounding area clean and hazard-free.
Biosafety cabinets are so vital for working with pathogens, we wanted to take a closer look at how they operate and what steps lab people and employees can take to keep them clean.
What is a Biosafety Cabinet (BSC)?
A biosafety cabinet (BSC) is a primary containment device used with biological material. While handling biological agents, it is the biological equivalent of using hazardous chemicals inside a fume hood. Like a chemical fume hood, a biosafety cabinet protects the user from hazardous material using directional air flow. Biosafety cabinets differ in that the air is also HEPA filtered, which removes biological contaminants.
The most common biosafety cabinet is the Class I ,Class II Type A2 biosafety cabinet, though there are many other types of ventilation equipment
Class I Cabinet
These cabinets are the least used because they don’t offer any “product” protection, with the product being the bacteria or virus sample. Although HEPA filters ensure that the air coming out of the cabinet is clean, unfiltered air comes in, contaminating the product. Usually, Class I cabinets are used to house specific equipment like a centrifuge.
Class II Biosafety Cabinets
This class offers product protection, and these cabinets can be broken down into various sub-classes, including A1, A2, B1, B2, and C1. The different subcategories of Class II cabinets refer to the amount of airflow and recirculation inside the unit. The most common type of Class II Biosafety cabinet is A2, but each subcategory has a particular application. For example, B2 cabinets don’t recirculate air, instead they use a duct exhaust system to remove contaminants and pathogens. These cabinets are primarily found in toxicology labs because they’re expensive to operate.
Class III Biosafety Cabinet
This class is the most secure, offering gas-tight seals and built-in gloves for working. Class III cabinets are often called glove boxes because of this setup. To prevent lab contamination, these cabinets use a dunk tank or double-door autoclave to trap pathogens and harmful particles. Class III cabinets are only used in maximum containment labs, such as those that work with BSL-4 pathogens (the most dangerous kind).
Which Industries Use BSCs?
Industries that work with pathogens and biological agents need to use biosafety cabinets. Examples can include:
* Universities and Institutes
* Research Labs
* Toxicology Labs
* Criminology Labs
Common Types of Contamination Found in a BSC
As you can imagine, it’s essential to maintain a sterile work environment inside a biosafety cabinet. Unfortunately, unsafe practices can cause various types of contamination, such as:
* Cross-Contamination of Products
* Dirt and Grime
* Mislabeled Materials
Also, because most BSCs create an “air curtain” to prevent pathogens from escaping, any biological elements in the air can wind up on all surfaces within the cabinet. For that reason, it’s crucial to replace filters and clean the cabinet regularly. In most cases, human error is the cause of contamination, which is why it’s so vital to have a biosafety cabinet cleaning procedure in place.
Safety Measures and Best Practices When Using a Biosafety Cabinets
Because biosafety cabinets are used for delicate and hazardous materials, workplaces must implement various best practices and cleaning procedures. Here’s a rundown of how to use BSCs safely to protect both workers and products.
A checklist is an essential tool for many complex jobs with multiple steps. Having workers follow a checklist system ensures that they don’t forget crucial steps. Even if workers have done procedures many times before, it’s easy to miss or forget something.
Test Airflow and Ventilation Before Use
BSCs should have sensors and warning systems in case the airflow gets interrupted or stops suddenly. Workers should run the air for a few minutes to ensure that these systems are working properly. If they are not functioning, the employee should notify a supervisor immediately.
Only Use BSCs as Intended
As we mentioned, there are different classes of BSC, which can be divided further into subcategories. Workers should be aware of the capabilities and limitations of a biosafety cabinet before performing any work inside of it.
Don’t Disrupt the Air Curtain
The cabinet’s airflow is crucial for maintaining a safe work environment. If employees disrupt the air curtain too much, they could potentially cause contamination of both the lab and the products. As a rule, employees should move perpendicular to the front of the cabinet as much as possible. This way, they don’t break the airflow too much at one time.
Replace Air Filters Often
HEPA filters are essential for a well-functioning BSC, but these filters can get contaminated quickly. There should be a replacement schedule based on the amount of use a cabinet receives. Be sure to read up on manufacturer recommendations as well.
Shut Off UV Lights Before Working
While UV lights can provide some level of sterilization, they can also be a health and safety hazard while working inside the BSC. Employees should shut off all UV lights before working to prevent potential risks.
Store Supplies and Equipment Outside the BSC
Before employees start working within the cabinet, they should know which items to bring in. According to OSHA, workers should only bring the items necessary for immediate use. The cabinet is not designed for long-term storage, as doing so could interrupt the airflow and lead to contaminated surfaces.
Use the Correct Biosafety PPE
The type of personal protective equipment necessary for use in a BSC depends on the nature of the work involved. However, here’s a rundown of the various PPE options that should be available to workers at all times:
3.Face Mask and Face Shield
4.Eye Protection (e.g., goggles or glasses)
Although the cabinet itself provides adequate airflow, some situations may require a self-contained breathing apparatus (SCBA). These devices should be worn in cases where pathogens may escape into the lab environment.
Dispose of PPE Properly
Once employees are finished working inside the cabinet, they should dispose of their PPE according to CDC and OSHA waste guidelines. Workers should never reuse PPE. Some materials, like an SCBA, must be cleaned thoroughly before reuse because they are not disposable.
Clean and Decontaminate the Cabinet Regularly
One question to ask employees is, “what steps should you take to decontaminate a BSC after you finish working?” Typically, the best option is to wipe down all surfaces with cleaning materials while the blower is still running. In many cases, workers should use a solution of 10 percent bleach, followed by a solution of 70 percent ethanol. It’s crucial to put these liquids on a sterile pad or wipe. No one should spray bleach or ethanol inside the cabinet.
While wiping the surfaces works well for everyday use, you’ll also need gas decontamination for a more comprehensive solution.
What is Gas Decontamination?
Instead of using wipes and cleaning solutions to sterilize surfaces, gas decontamination uses aerosolized gas to permeate the cabinet and kill any bacteria or viruses that may be present. This decontamination method works well for ensuring that the cabinet stays sterile at all times. However, the gas will not remove surface dirt or grime.
Several gases can be used for decontamination, but chlorine dioxide is the most common.:
No Condensation – Since this is a “true” gas, it won’t bind to water vapor in the air and create condensation.
No Toxic Byproducts – Chlorine dioxide produces oxygen and salt, so workers don’t have to worry about secondary contamination after spraying the gas.
Fast Application and Cleaning – Typically, chlorine dioxide decontamination takes up to 90 minutes for application and another 30 minutes for scrubbing afterward.
That said, chlorine dioxide can potentially lead to some metal corrosion, so workers have to be careful to avoid corroding the inside of the cabinet. If chlorine gas is present, this problem can be much worse.
When Should Workers Use Gas Decontamination for BSCs?
There are several reasons why gas decontamination may be necessary, such as:
* Relocating the Biosafety Cabinet
* Disposing of a BSC
* After a Large Spill
* Before Filter Changes
Because of the nature of gas decontamination, regular workers should not conduct the procedure themselves. Instead, it’s better to use a third-party provider that can guarantee their work. Professional gas decontamination companies will also have the right tools to complete the job correctly.
Contact AiFurnaces for Your Biosafety Cabinet Today for further details.
Choosing, upgrading, and maintaining a biosafety cabinet is critical to ensure safety for laboratory workers and the environment.
By evaluating factors such as the type of agents or materials used, risk level of the work, volume of materials, and work practices and procedures, laboratory managers can choose the most suitable biosafety cabinet.
Additionally, it’s crucial to have the biosafety cabinet certified regularly and conduct routine maintenance to ensure it’s running properly. Contact us for NSF49 Certified BSC Equipment, we also offer the calibration service for more laboratory equipment.