Fire Safety in Aerospace & Defense Cleanrooms

Fire Safety in Aerospace & Defense Cleanrooms

Aerospace and defense cleanrooms already work hard to protect sensitive equipment and materials from the various risks associated with contaminant particles. However, designers also need to be aware of another significant risk these cleanrooms can bring to facilities, materials, and operators: fires. 

Due to the high-velocity, constantly moving air flow within them, cleanrooms present a unique challenge for traditional fire prevention and suppression. But when you’ve spent the time, energy, and money to install one in your facility, it’s critical that you’re doing everything you can to protect your investment and keep operations running. 

Here’s an overview of some of the most common cleanroom fire hazards, as well as some tips on how to prevent them. 

Fire Hazards in an Aerospace & Defense Cleanroom

Cleanrooms need to have high air exchange rates, fast air velocities, and uniform air flows to consistently filter contaminant particles out of the space. However, these operating conditions have a negative consequence when it comes to fire control. They make it much more difficult to detect a fire with standard fire detection and suppression systems — often resulting in fires being detected too late, after damage has already occurred. 

To prevent these scenarios from happening, two things are important: 1) understanding the common fire hazards within your cleanroom, and 2) knowing the right tools and techniques to prevent them. 

First, let’s dive into three of the most common cleanrooms fire hazards, which are listed below: 

1. Short-Circuits

Cleanrooms are designed to host various types of machinery and equipment. For this reason, they’re usually equipped to handle a large electrical load. However, there’s always a chance of equipment overloading or short-circuiting that could cause them to catch fire. 

2. Improper Handling of Heat Sources

From hot air guns to Bunsen burners, there are many heat sources that can be used within an aerospace and defense cleanroom. If any of them are mishandled or stored improperly, they can result in disastrous damage. 

3. Leaking of Highly Flammable, Pyrophoric Materials

If your cleanroom deals with any liquids that can spontaneously combust on contact with air or moisture, it’s important to diligently store and secure them. Otherwise, they have high potential to leak and cause a fire or explosion. The same goes for any explosive concentrations of gases or solvent vapors. 

Fire Safety Tips for Aerospace & Defense Cleanroom Design

Looking at each of those hazards, it’s easy to get nervous about something tragic happening to your own facility or employees. The good news? Most often, cleanroom fires are preventable (or at least easier to suppress and minimize damage) with the proper tools and protocols. We’ve outlined the three most important cleanroom fire safety tips below: 

1. Invest in Specialized Fire Detection Equipment

Standard fire detection systems don’t always provide the best results in cleanrooms. However, there are specialized fire detectors that are specifically designed for controlled cleanroom environments. They actively work to collect random air samples at various suitable points within your cleanroom, so that any smoke can be detected at an earlier stage. 

Specialized fire detectors are often integrated with voice alarms and fire extinguishing systems as well. That way, all systems can be activated as quickly as possible and can respond to any fire hazards that are detected. 

2. Install Multiple Types of Fire Suppression Systems

In many cases, aerospace and defense cleanroom operations involve the handling of materials that, when combusted into flames, cannot be extinguished with water alone. For that reason, you should generally ensure that your cleanroom has multiple types of fire suppression systems. 

Most often, you’ll find that properly protected cleanrooms have a water-based sprinkler system. However, they’ll also usually install various fire extinguishers that are filled with inert gases (argon or nitrogen). That way, no matter the cause of the fire, their facility and employees are well-protected. 

3. Implement a Plan for Orderly Evacuation

When you think of a normal fire drill/evacuation, your immediate response is likely to just get out — wherever you can, however you can, as fast as you can. But with cleanrooms, this process often needs to be a little different, mostly because you don’t want to risk the release of any toxic substances that may be held within them upon exiting. Therefore, it’s important to put an orderly evacuation plan in place, and to make sure your cleanroom operators understand it.

Even better? Many cleanroom facilities invest in voice evacuation systems that alert and inform personnel of the situation, transmit clear instructions, and detail a safe evacuation plan. They’re a great resource to ensure proper protocols are followed, even in the event of a stressful emergency. 

Need to boost your cleanroom’s fire safety measures? At Angstrom Technology, we’re here to help. Our engineers can design cleanrooms that incorporate a variety of design features, including fire suppression and alarm systems. To get started on yours, give us a call or contact us online today. 


5 Biggest Threats to Medical Cleanrooms

5 Biggest Threats to Medical Cleanrooms

5 Biggest Threats to Medical Cleanrooms (and How to Prepare for Them)

In the medical industry, there’s no room for error. The slightest amount of contamination can not only result in reduced efficiency and missed development deadlines, but it can also put human lives at risk. 

Keeping your medical cleanroom airtight, fully controllable, and customized to meet your application’s ISO classification is essential in conducting safe, effective, and efficient operations. You can accomplish this by understanding and planning ahead for any risks your cleanroom may encounter. Below, we’ll outline five of the biggest threats to medical cleanrooms, as well as how you can prepare for them. 

5 Biggest Threats to Medical Cleanrooms

While some threats to medical cleanrooms are fairly common sense, others may take you by surprise. Either way, it’s important to take all into consideration throughout the design and installation processes. Here are five of the most common threats medical cleanrooms regularly face: 

1. Personnel Within the Medical Cleanrooms

Staff members are known to pose the greatest risk for cleanrooms — and medical cleanrooms are no exception. Improper or disregarded handwashing and gowning protocols can result in thousands of contaminant particles being introduced — from skin particles to hair strands, to perfumes and cosmetics. In fact, some cleanroom inspections have attributed personnel as the cause for 80% of identified particles. 

2. Medical Cleanroom Materials

Work samples and materials within medical cleanrooms can also pose a health threat to personnel. In many medical cleanroom applications, cleanroom operators work with microbiological substances that can cause serious harm if they aren’t contained and controlled properly and if operators aren’t wearing correct protective gear. From studying infectious diseases to dealing with bodily fluid samples, it’s important to be aware of potential biosecurity risks. 

3. Equipment in Your Medical Cleanroom

The machines and tools within your cleanroom pose varying levels of contamination risk. Machines often emit gas, lubricants, emissions, and other airborne particles while in use. Also, everyday tools like pens, beakers, trays — even cleaning items — can all introduce particles if not sanitized properly before use or handled appropriately during use. 

4. Dysfunctional Filtration Systems

If your medical cleanroom’s filtration system isn’t working properly, your cleanroom likely isn’t all that clean. Filtration systems — consisting of fans, pre-filters, and HEPA or ULPA filters — are responsible for treating contaminated air supplies and maintaining consistent air change rates in order to ensure good air quality. However, over time, their components can grow old and function at lower capacity, increasing the chance of higher particle counts and dead zones.

5. Static in Your Medical Cleanrooms

Static electricity in medical cleanrooms isn’t always a risk that comes first to mind — but it’s definitely one to take into account. Its “cling” effect increases the chance of attracting airborne particles to surfaces that need to remain sterile. Also, in applications involving medical device development, static can cause particles to be drawn in and permanently damage sensitive electronic components. 

How to Prepare Your Medical Cleanroom for Safe Operations

Fortunately, there are ways to prepare for and prevent each of the medical cleanroom threats listed. Although complete sterilization is virtually impossible, implementing the right tools, technologies, and procedures can help you reduce risk as much as possible. Here are a few preparation tips to consider during the design and installation processes:

Install and Maintain a Fully Functioning Filtration System

In order for your cleanroom to meet its ISO classification requirements, you need to install a quality filtration system. Make sure that your filtration system provides the required percentage of ceiling coverage and maintains consistent air exchange rates. 

And, once it’s designed and installed properly, make sure you stick to a regular filtration system inspection and maintenance schedule. Your pre-filters should be replaced at least six times per year, and your HEPA or ULPA filters should be replaced at least once every three years. If not maintained properly, your filtration system could fail and threaten control over your cleanroom environment. 

Apply the Right Type of Pressurization for Your Medical Cleanroom’s Application

Both positive and negative pressure cleanrooms have their place in the medical industry — it just depends on your specific application. Most medical cleanrooms operate with positive pressure, using HEPA filters and an external airflow pattern. However, some applications involving hazardous substances need negative pressure to prevent contaminants from escaping and causing harm to the surrounding environment. 

Include Pass Throughs in Your Medical Cleanroom Design

Pass-throughs are chambers for moving products in and out of your cleanroom. Adding one or more pass-throughs to your medical cleanroom can make transferring tools and materials quicker and more efficient. At the same time, pass-throughs reduce cleanroom traffic cross-contamination, helping to provide a less compromised work environment.

Adopt Thorough Cleanroom Cleaning Protocols

Medical cleanrooms require some of the most stringent ISO standards — and while your cleanroom may be designed with features and technologies to uphold that, you still need to do some cleaning as well. By establishing a daily, weekly, and as-needed set of cleaning tasks, you’ll ensure your cleanroom is operating at its maximum possible sterilization levels. 

While you’re cleaning, make sure to use specified cleaning products for medical cleanrooms like distilled water, neutral chemical solvents, and non-shedding cloths or wipes. How you clean is just as important as how frequently you clean. 

Implement Anti-Static Cleanroom Components

Controlling static isn’t always easy, but it is possible. There are many specialized products made for controlling static within a cleanroom, including anti-static flooring and wall panels. On top of this, a great way to control static is to adopt clothing and gowning guidelines that limit it. These could include anti-static garments, ESD cuffs, low-static shoes, or basic lab coats. 

No matter the specific environmental threats your facility and application may face, Angstrom Technology can design and install a medical cleanroom that controls and prevents them all. Contact our team to get started today. 

Understanding Biological Safety Levels

Understanding Biological Safety Levels

In any cleanroom application, safety is top priority — for the benefit of both operators and end consumers. In order to ensure the safety of all, various industry authorities have created guidelines for cleanliness and protection.  When it comes to applications that require working with potentially hazardous biological microorganisms, the Centers for Disease Control and Prevention (CDC) have established the leading regulations: biological safety levels (BSLs). Let’s explore more about what BSLs are, and how they may be applied in your cleanroom. 

What Are Biological Safety Levels? 

BSLs are sets of biocontainment precautions required to isolate potentially hazardous biological microorganisms in enclosed, controlled environments. They’re intended to ensure operator safety by outlining recommendations for safe operating procedures and atmospheric controls. BSL protocols are used everyday in a number of industries and applications, from medical, to microbiology, to environmental testing. 

The Four Biological Safety Levels

The CDC has proposed four BSLs, each of which is associated with a varying degree of danger, and a set of appropriate operational protocols. These levels range from Biosafety Level 1 (least hazardous) to Biosafety Level 4 (most hazardous). Below, we’ll explain the basics of BSL 1, 2, 3, and 4. 


BSL-1 requires a basic level of protection against agents that aren’t known to cause disease in healthy, non-immunocompromised humans. This could include non-pathogenic and non-infectious bacteria like E.coli. Usually, there are doors that separate a BSL-1 lab from the rest of the facility, but within those doors, operators can do open-bench work with just the most standard regulations in place: personal protective equipment (PPE), hand washing, and decontamination of work surfaces after use. 


BSL-2 requires a level of protection appropriate for handling moderate-risk agents, known to cause varying degrees of disease in humans. This could include the microbial organisms like Staphylococcus aureus or Salmonella. A BSL-2 cleanroom is restricted from the rest of the facility behind self-closing doors, and features various biological safety cabinets (BSCs) to perform procedures safely in. Operators are required to wear additional PPE, including a face shield, and follow each of the standard cleanliness regulations as in BSL-1. 


BSL-3 requires protection against “exotic” airborne microbial agents that are known to sometimes cause fatal reactions in humans post-ingestion. An example of one of these agents is Mycobacterium tuberculosis. Because of the potentially deadly nature of these microbes, BSL-3 cleanrooms require even more enhanced protection protocols, including:

  • The lab must be restricted behind two sets of doors.
  • Operators must be immunized and wear PPE, plus respirators. 
  • All work must be performed in a BSC. 
  • Filtered room air must be exhausted appropriately. 


BSL-4 requires the maximum amount of preventative measures and protection. It’s recommended in labs that handle agents that have a high risk of airborne transmission and are frequently fatal for humans. Often, this includes microbial agents that we don’t yet have a treatment for, such as Ebolavirus. BSL-4 necessitates that operator and environmental protection is at its highest level, meaning the following protocols are in place:

  • The lab is located in a completely separate building. 
  • Operators must wear PPE, including a full-body, positive-pressure cleanroom suit. 
  • Operators must shower after exiting the lab. 
  • All work must be performed in a Class III BSC. 
  • All material must be decontaminated before exiting the lab. 

Biological Safety Levels vs. ISO Classifications: What’s the Difference?

While BSLs and ISO classifications are both withheld in cleanroom environments, there isn’t much correlation between them because they deal with different issues: protection of operators from biological exposure vs. protection of sensitive product materials from contaminant exposure. That being said, BSLs work in tandem with ISO classifications, with most requiring ISO Class 7 cleanrooms with separate gowning and degowning rooms. It’s best to have a conversation with your cleanroom manufacturer to get a sense of how to accommodate both needs and keep your operators, products, and environment safe all at once.  Maintaining a controlled, biosafe environment is critical for many environmental and medical cleanroom applications. If you need a cleanroom that’s designed to meet specific design or cleanliness requirements, contact Angstrom Technology. Our team of experts is happy to help you build the solution you’re looking for.