Addressing Safety Challenges in Clean Room Environments
Controlling the environment inside a clean room introduces safety challenges. With careful management, these hazards can be controlled.
Clean rooms are unique work environments, complete with unique challenges for safety professionals.
Clean rooms are found in different industries and in various types of facilities. They're used in the creation of pharmaceuticals as well as the manufacturing of microchips. They're also required for certain types of scientific research.
While each clean room is unique, they have one thing in common: they're designed to minimize the presence of particulates and contaminants. This is accomplished by various measures, including:
- Mandating the use of disposable coveralls
- Installing air showers at points of entry
- Using sticky mats to capture particulates
- Air filtration systems
- Controls to manage the clean room atmosphere
Some clean rooms also require careful control of additional factors, such as temperature, humidity, or pressure.
Hazards in Clean Room Environments
Let's start by considering the scope of these facilities.
Some clean rooms are relatively small - only large enough for one or two employees to carry out their work. Others are quite sizeable. Consider, for example, the massive assembly rooms used in the manufacturing of electronic devices and their components.
Or better yet, think of NASA facilities. As you can imagine, it takes an especially large clean room to assemble a spacecraft.
And given our current reality, clean room standards have been applied in healthcare settings to ensure the protection of patients and medical personnel.
Add to that the design elements that are intended to manage the clean room environment. Among other things, that might include:
- Air locks
- Pass-through doors
- Gowning rooms
- Static control
- Sealed environments
- Humidity and temperature controls
- Sticky pads on the floor
- Fire suppression systems
- Workers using powered personal respirators or SCBAs
On top of that, some clean rooms are positive pressure environments, which introduces a whole set of hazards in and of itself. Take a look at the ISO Clean Room Standards (ISO 14644 and the FS 209E equivalent) for a breakdown of the different levels of clean room.
Depending on the room, you might also be dealing with a confined space or a lone worker situation.
All of this makes safety in the clean room extremely complex. Complex, but still manageable.
Hazard Identification Starts at the Design Stage
Your hazard identification work has to be comprehensive. it needs to consider the construction of the room itself, the equipment used, and the raw materials brought into it.
In fact, the process should begin at the design stage for the room itself. And this will require expert help, because establishing such a strict separation between the clean room and the area outside it creates hazards for both spaces.
Consider the filtration system, for example. HEPA filters will be required, which means regular maintenance, testing, scheduled filter changes, monitoring, and record-keeping. You also need to consider where your makeup air (the air that replaced the one exhausted from your clean room facility) is coming from and the potential breathing hazards that can be introduced with it.
Slips, trips, and falls are one of the common causes of worker injury. Sticky mats are a great mechanism for controlling particulate matter, but if you leave one unanchored it can become a tripping hazard.
Limited access and egress are also a factor, especially in a rescue scenario. Panic bars on the doors can make it easier to leave the clean room in an emergency situation. Same with emergency exits. And fire and contaminated environment atmosphere alarms can be life-savers.
Your hazard identification process will help you create a hazard inventory for your clean room. After that, use a ranking tool to determine which hazards have a higher priority.
Where do you go for a comprehensive list of known clean room hazards? Unfortunately, that's a question without a simple answer. Find others who do what you do and ask them for help. Talk to manufacturers and vendors who deal specifically with the clean room industry. Spend some time looking at the relevant resources available from the CDC, NIOSH, ANSI, and OSHA. That will give you a better idea of what to look out for.
Managing Safety in a Clean Room
Once the hazard inventory for the room and the work that takes place in it have been completed, it's time to make sure your safety management processes comprehensively address them.
This includes, but is not limited to:
- A clean room safety policy
- Identified clean room work, entry, and exit procedures
- Workflow or process maps for all aspects of the room and the work
- Clear job descriptions and job documents for work that takes place in the room
- Education and training, including daily safety briefings specific to issues relevant to the clean room
- A task list, reviewed at least once a month and whenever there is a change
- A reporting system for failures and incidents
- An inspection schedule
- A clear chain of command and reporting process for errors, omissions, and instances of non-compliance
- PPE purchasing, use, and disposal (including peripheral items like sticky mats)
- A system to ensure the correct air filtration system is in place and regularly maintained
- Testing for airborne particulate matter
- A management system for the rate of air changes per hour
- Systems to manage a confined space or a lone worker situation (for jurisdictions where the clean room falls under these categories)
Consult ISO 14644
Be sure to also consider the following ISO 14644 sections:
- Number and size of particles permitted per volume of air
- Required testing (particle count, air pressure difference, airflow, class, maximum time interval, and testing procedure)
- Optional testing
- Filter leakage
- Containment leakage
- Airflow visualization
The following is a listing of ISO clean room sections/documentation (new and revised):
Classification of Air Cleanliness
Cleanroom Testing for Compliance
Methods for Evaluating & Measuring Cleanrooms & Associated Controlled Environments
Cleanroom Design and Construction
Terms, Definitions and Units
Enhanced Clean Devices
Biocontamination: Control General Principles
Biocontamination: Evaluation and Interpretation of Data
Biocontamination: Methodology for Measuring Efficiency of Cleaning Inert Surfaces
If you're operating in the United States, two resources to know about are the Institute of Environmental Sciences and Technology (IEST) and the Standards Order Desk of the Naval Publications and Forms Center.
Keep Your Clean Room Safe
This subject of clean room safety is a complex one. The safety professional tasked with it is going to need help, information, and education - not only from relevant standards but from manufacturers and suppliers as well.
In my professional opinion, a clean room also requires the services and assistance of an Industrial Hygienist. They will help you handle the air quality, movement, and testing.
Your organization's success depends on the effectiveness of your safety management, and that's no less true when it comes to your clean room facilities. Taking the time to ensure that the environment is not only well-controlled but also safe will be worth your while.