Hazardous material storage cabinets serve several critical functions. First and foremost, cabinets provide for the safe containment of hazardous chemicals, which helps protect personnel and property from devastating fires.
Different sizes of cabinets can be positioned in the work area near points of use, saving costly trips to a central storage room. Locking mechanisms help ensure that hazardous chemicals are being used only by properly trained, authorized personnel.
In addition, safety cabinets provide the perfect means to maintain a good housekeeping program. They help identify, organize and segregate dangerous liquids.
With such a wide selection available in today's marketplace, how do you select the safety storage cabinet best suited for your application? Begin by asking yourself some basic questions:
- Which federal regulations apply? What about state or local regulations? Do industry standards or model codes offer guidance?
- Has the cabinet been performance tested?
- How much of each chemical is needed in any given work area per day or per shift? Do I need any special features to fulfill my specific needs?
Following are answers to some of these questions. Other answers will depend on your storage situation.
OSHA regulation 1910.106 applies to storage of flammable and combustible materials. State and local codes likely are based on the National Fire Protection Association code (NFPA 30) or Uniform Fire Code (UFC) 79.
Section 4-3 of the 1996 edition of NFPA's codes covers the design, construction and capacity of storage cabinets.
4-3.3(a). Storage cabinets are acceptable if designed and constructed to limit the internal temperature at the center of the cabinet and 1 inch from the top of the cabinet to not more than 325 degrees when subjected to a 10-minute fire test that simulates the fire exposure of the standard time-temperature curve specified in NFPA 251, Standard Methods of Tests of Fire Endurance of Building Construction and Materials.
4-3.3(b). Metal cabinets are acceptable if the bottom, top, door and sides are at least No. 18-gauge sheet steel and are double walled with 1 1/2-inch air space. Joints must be riveted, welded or made tight by some equally effective means. The door must have a three-point latch arrangement, and the door sill must be raised at least 2 inches above the bottom of the cabinet to retain spilled liquid within the cabinet.
4-3.5. Storage cabinets must be marked in conspicuous lettering: "Flammable -- Keep Fire Away."
One notable distinction in UFC is the requirement that all flammable and combustible liquid cabinets shall be self-closing.
In addition to ensuring that cabinets meet applicable codes, it's important to look for cabinets that carry independent, third-party certification, such as Factory Mutual (FM) or Underwriters' Laboratories.
FM-approved safety storage cabinets are loaded to capacity for 72 hours and subjected to a 10-minute fire test, during which exterior experiments reach as high as 1,300 degrees. Spill containment is physically tested. Tests are also conducted to verify that hold-open devices release properly, and doors close and latch in the event of a fire.
Look for the label. Third-party approvals are confirmation that products do what they claim they will do. Most insurance companies recommend using approved safety products.
When it comes to storing hazardous materials, it's the performance that counts. Cabinets that have been performance tested and meet applicable codes are the only cabinets that should "qualify" for use.
Identify how much chemical capacity is needed for existing and future needs. How does the volume of chemical stored affect cabinet selection? There are applicable codes relating to flammables and combustibles. NFPA 30 addresses these issues.
4-3.1. Not more than 120 gallons of Class 1, Class 2 and Class 3A liquids must be stored in a storage cabinet. Of this 120-gallon total, not more than 60 gallons can be Class 1 or Class 2 liquids.
4-3.2. Not more than three storage cabinets can be located in any one fire area.
5-5.4.1. The aggregate of the sum of all incidental operations in each fire area cannot exceed the sum of:
- 25 gallons of Class 1A liquids in containers;
- 120 gallons of classes 1B, 1C, 2 or 3 liquids in containers;
- Two portable tanks each, not exceeding 660 gallons, of classes 1B, 1C, 2 or 3A liquids; and
- 20 portable tanks, each not exceeding 660 gallons, of Class 3B liquids.
An exception is made where quantities in excess of the above limits are needed to supply an incidental operation for one continuous 24-hour period.
Within the parameters of third-party certification and applicable code, what size and style of cabinet is most practical? Qualified cabinets are available in capacities ranging from 12 to 120 gallons.
Does your work area lend itself to using a standard floor style with self-leveling feet, or would cabinets that slide under a bench, counter or fume hood be more convenient? Perhaps stacking "piggy back" cabinets is your best option. When the liquids are stored in small bottles or other vessels of limited capacity, consider using a wall-mounted cabinet.
When managing 30- or 55-gallon drums, single or double drum cabinets should be used. Cabinets are available for vertical or horizontal placement for storage and dispensing.
Besides mandated design and construction details, there are other factors to be considered when making a cabinet selection.
Units that incorporate welding tend to hold squareness and rigidity better, resulting in a longer life. Cabinets with concealed self-closing mechanisms provide full access to top shelf space, unlike those with exposed mechanisms that restrict space.
Door styles vary from single to double door and from manual closing to self-closing to sliding-door closing. Users in states adhering to UFC must have self-closing doors.
Doors that self-latch make door closing easy with no need to pull down a handle to lock in place. This encourages complete closure of doors to maintain the fire protection integrity of the cabinet.
Shelving within the cabinet should offer convenience and durability. Shelves with simple, built-in troughs help catch incidental leaks, making cleanup easier. Ribbing provides extra strength and rigidity. The ability to interlock onto internal cabinet tabs can help prevent bothersome shelf slippage.
The finish should prolong the life of the cabinet. A powder paint finish, for example, offers chemical and corrosion resistance.
Other factors to consider include whether seismic adapters would be beneficial for earthquake-prone areas or whether venting is required per local jurisdictions.
An informed choice is always the best choice. After a thorough evaluation, you can be assured of making the cabinet selection that meets your personal needs and governmental requirements.
David Evans is manager of product development for Justrite Manufacturing Co., Des Plaines, Ill.