On every lab project, at some point in the design process, someone asks the question: "what chemicals will these guys use?" It seems like a simple question; but it's actually quite a complicated issue, and it can have significant consequences. Failure to get this answer right have resulted in situations where the local code officials have either refused to issue new building permits until the situation is corrected or have even threatened to padlock the doors of a facility. When you do anticipate and plan for this issue, it can significantly impact the design of your building. So, how do we get the right answer to this question?
First, we need to look at what the code says. Most lab buildings today are designed as B-Occupancy buildings in which hazardous chemical usage is governed by table 307.1(1) of the International Building Code (IBC). The code sets maximum limits for storage, in-use open and in-use closed systems for 41 different classes of chemicals based on a defined control area. In addition, table 307.1(2) sets limits for hazardous materials that pose a health hazard. In most cases, these quantities can be doubled if the building is fully sprinklered, and can be doubled again if quantities are stored in rated cabinets and safety cans.
Designers and building owners are free to place control areas wherever they want on a floor, but Table 414.2.2 sets restrictions on the number of control areas per floor, the percentage of the maximum limit that can be utilized for each control area and what the fire separation between areas needs to be. When the quantity of any given chemical exceeds the maximum allowable quantity per control area, quantities must be stored and used in Hazardous Occupancy spaces (H-rooms). These spaces are distinguished by fire-rated enclosures, increased sprinkler densities, dedicated exhaust systems and intrinsically safe electrical systems. Fortunately, any chemicals stored in an H-room don’t count towards the limits of the control area in which the H-room is located.
Most organizations run into code violation problems regarding the classes of chemicals used most frequently (Class IB Flammable Liquids), or the classes of chemicals where the limits are so low even small quantities push them over the limits (Pyrophorics or Class 4 Oxidizer).
Why don’t some facilities comply?
This brings us to the first reason buildings don’t meet code. Most older lab buildings were built to a different building code. Many older buildings have either outdated or no guidelines for what is and isn't allowed for chemical use. We now know a lot more about the hazards of chemical use inside of labs than we did 20 years ago; and there’s a much greater awareness of the issue now than ever before, shining a spotlight on where organizations are out of compliance today.
But we sometimes find even new buildings out of compliance. Typically, this is created by a breakdown in communication between the designers and the final users of the space. Either designers don't understand the chemical usage requirements of the users or the users aren't made aware of any restrictions placed on their chemical usage.
How should we count chemical quantities?
I've heard two approaches commonly cited by lab planners as to how to approach chemical quantities. The first is layout the maximum number of control areas allowed per floor and simply tell researchers what their limits are and expect them to comply. The second is look at the existing inventory of chemicals and verify it fits within the planned control areas.
Neither of these approaches is great. The first relies on the users knowing what the limit is and what portion of the allowable quantity they can use. Unfortunately, this information is rarely transmitted to users and there’s very rarely any institutional memory to keep this alive. The second approach relies on the accuracy of the chemical inventory. The problem with chemical inventories is they start out 90% accurate and get progressively less accurate over time. They are only a snapshot in time and past results are no indication of future trends. They don't tell you whether a chemical is in-use on the open lab bench or closed and stored in a rated cabinet. And what about future growth?
How can a lab planner help?
Lab planners need to have a much deeper understanding of how researchers are storing, using and disposing of chemicals. They must take into consideration how chemical quantities fluctuate over time and how future changes in types of research may impact relative quantities of chemicals. Simply taking a passive approach and placing responsibility on the users and their management to stay within limits is not adequate. Lab planners have to provide a plan that’s capable of limiting chemicals to allowed amounts, while still allowing lab-users to perform their research.
A better approach is to employ what we call the predictive model for chemical usage that allows a much deeper understanding of chemical quantities than an inventory alone. By investigating how and where chemicals are used, we can build a mathematical model that will tell us what the anticipated chemical loading will be. An easy-to-follow set of rules are established (all hazardous chemicals not in use must be stored in rated cabinets, we place limits on the sizes of supply and waste reservoirs for analytical instruments, etc.). We then develop a design based on these rules and that reinforces proper user behavior and easy verification of compliance. We have found this much more accurate than relying on inventories; and it allows us to evaluate quantity reduction methods, evaluate the implications of future growth and demonstrate to code officials that the new design will be in compliance.
What do you do when your chemical quantities exceed the limits?
If you find yourself in this situation, there are still many options you can choose. The first step is to do a chemical clean-out and get rid of empty, identical bottles of expired chemicals inside the lab. It never ceases to surprise me what I find in labs that no one realizes was there, and has no idea who it belongs to.
After doing this clean-out, a common approach is to create H-rated storage rooms. As previously stated, the quantities of hazardous chemicals stored in H-rooms don’t count towards the total quantity of the control area they are located within. Within a B-occupancy building, these storage rooms can be up to 10% of the floor area. These rooms provide researchers space to get excess chemicals out of the lab and safely stored. It’s possible to create entire H-rated floors or buildings, but this is only possible with the most restrictive construction types and with large setbacks from other buildings. We find the notion researchers can have as many chemicals as they want to be disconcerting, and believe there always should be some sort of strategic safety limit on the allowable quantity of chemicals, whether the code requires it or not.
There are also mechanical methods for reducing chemical quantities, as well. A discussion of these could be an entire article on its own, but these fall into two basic categories: piped chemical supply systems and piped chemical waste systems. These methods rely on holding large quantities of commonly used chemicals and waste outside the lab.
At the end of the day, it truly is the responsibility of the lab users, their chemical suppliers and the Environmental Health and Safety (EH&S) groups to make sure their chemical quantities are in compliance; however, for lab planners to simply rely on unenforceable limits or outdated inventories won’t work. It’s the responsibility of the lab planner to ensure facilities and researchers have the tools to make this possible.
Greg Muth is a well-respected leader in the design and planning of sustainable lab and research spaces. An enthusiastic and thoughtful problem-solved, he relishes partnerships that engage all participants in the exciting process of discovery.