flammable, combustible or corrosive liquids can be confusing. There are many regulations that apply to their storage, handling and dispensing, designed to protect employees from injury and prevent fires and explosions. Failing to meet the requirements carries the potential for large penalties and fines. You can help avoid these penalties by storing chemicals in approved chemical storage buildings or cabinets.
Regulations for Chemical Storage
Chemical storage regulations are based on how dangerous the chemical is. The NFPA and OSHA classify chemicals based on their physical and chemical properties. The more flammable a chemical is, the higher the restrictions on its use and storage. Summary tables of the two classification systems are as follows:
| Class | Flashpoint | Boiling Point |
|---|---|---|
| I-A | < 73.4 F (23 C) | <= 100 F (38 C) |
| I-B | < 73.4 F (23 C) | >= 100 F (38 C) |
| I-C | 73.4-100 F (23-38 C) | |
| II | 101-140 F (39-60 C) | |
| III-A | 141-199 F (61-93 C) | |
| III-B | >200 F (>93 C) |
Table 1 – NFPA Flammable Classifications
| Category | Flashpoint | Boiling Point |
|---|---|---|
| 1 | < 73.4 F (23 C) | <= 95 F (35 C) |
| 2 | < 73.4 F (23 C) | > 95 F (35 C) |
| 3 | 73.4-140 F (23-60 C) | |
| 4 | 140-199.4 F (60-93 C) |
Table 2 – OSHA Flammable Categories
Small Volumes of Chemicals Don’t Need Special Storage
Regulations allow the storage of very small volumes of flammable liquid outside cabinets or chemical storage rooms. These liquids must be in containers and have the following limits:
- 25 gallons of Category 1*
- 120 gallons of Category 2, 3 or 4
- 660 gallons of Category 2, 3 or 4 in a single portable tank
*Per IFC Table 911.1, 1A flammable liquids require explosion control methods regardless of volume stored.
Flammable Chemical Safety Cabinets
Flammable chemical safety cabinets are specially designed and constructed chemical storage cabinets. They increase the volume of chemical stored inside a building for ease of access by workers. Most cabinets contain sufficient supplies for daily use. But, there are still strict volume limits depending on the flammable classification of the materials stored.
Maximum allowable chemical storage in safety cabinets is as follows:
- 60 gallons of Class I and II (Category 1, 2 and 3)
- 120 gallons of Class III (Category IV)
Regulators allow the use of more than one chemical safety cabinet to extend these storage volumes further. There is a limit of three safety cabinets per internal storage area.
Chemical Storage Buildings
Chemical storage buildings are for bulk storage of flammable, combustible and corrosive chemicals. The maximum size of a chemical storage building is 1,500 square feet. This can be extended with the approval of regulators and insurance providers. Chemical storage buildings are prefabricated off site and then assembled at the required location. Most stand away from occupied buildings, but legislation allows for their inclusion in an occupied building if they meet the required fire rating.
According to IBC, for hazard occupancy of H2 or less, fire ratings and location distances for chemical storage buildings are as follows:
- Non fire-rated: more than 30 feet from an occupied building
- 2-hour fire-rated: between 10 and 30 feet from an occupied building
- 4-hour fire-rated: within 10 feet of an occupied building
Factors to Consider when Determining What Chemical Storage Method to Use
| Safety Cabinet | Chemical Storage Building | |
|---|---|---|
| Regulations | OSHA 29 CFR 1910.106 NFPA 30 | OSHA 29 CFR 1910.106 NFPA 30 and 70 UFC Articles 79 and 80 EPA 40 CFR 264 IBC, IFC, NEC |
| Secondary Containment Required? | Yes. Door sills must be raised 2 inches above the floor for containment purposes. | Yes. A spill containment sump must have capacity for 100 percent of the largest container or 10 percent of the total volume of all containers, whichever is the greater. |
| Venting Required? | Not recommended unless specifically required by local authorities. | Yes. Chemical storage buildings must be vented to remove hazardous vapors. Mechanical ventilation is the safest method to ensure flammable vapors are drawn out of the building at all times. |
| Explosion Relief Panels | N/A | Explosion relief construction is required if storing or dispensing Class IA or dispensing Class IB materials. |
Simple Tips for Flammable and Combustible Liquid Storage Compliance
- Check the chemical’s Safety Data Sheet (SDS). This indicates which flammable class or category your chemical fall into.
- Determine the chemical volumes required on site.
- Decide on the location. What volume of chemical do you need inside the facility? How far away could you practically locate a bulk storage area?
- Always use an FM- or UL-approved safety cabinet or chemical storage building. This ensures that the cabinet or building meets the regulatory requirements.
- Regularly inspect cabinets and storage buildings to ensure they are in good condition and are being used as per design.
Contact U.S. Chemical Storage for Compliant Chemical Storage Buildings
U.S. Chemical Storage, part of the Justrite Safety Group, supplies chemical storage buildings for flammable and combustible materials. We also have access to the Justrite range of safety cabinets. As experts in chemical storage, we can help assess your needs and recommend the best solution to keep you safe and compliant. Find out more here.
References
- Justrite. Redbook
- Grainger. Flammable Liquid Handling and Storage
- Grainger. Outdoor Chemical Storage Buildings
- Safeopedia. Hazardous Materials: Is Your Chemical Storage Solution Compliant?