Chemical Segregation and Storage
Each laboratory must have adequate chemical storage areas that provides sufficient and defined barriers between incompatible chemicals. Information on proper chemical storage can be found in the SDS and hazard assessment for each chemical.
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Where Should Chemicals be Stored in the Laboratory?
Storage areas should be easily accessible, dry, well ventilated, and located away from sunlight and ignition sources. Shelves and cabinets where chemicals are stored should be treated, coated or constructed of materials that are compatible with the chemicals being stored, and have a lip or guard along the exposed edge.
How are Storage Areas Identified?
Cabinets should be clearly labeled as chemical storage areas by:
- Using a pictogram of the primary hazard category contained in the cabinet;
- A sign indicating that the cabinet contains chemicals;
- See-through panes that allow visibility of the cabinet’s contents; or
- Other marking that clearly indicates the storage of chemicals.
How are Chemicals Stored?
Chemicals must be segregated by chemical compatibility and should be stored below eye level to minimize accidental exposure from spills.
- Solids should be stored above liquids.
- Secondary containment should be used to segregate incompatible chemicals and control spills for containers of hazardous liquids greater than 1.3 gallons (5L).
- Only limited quantities of chemicals should be stored in the laboratory.
When Should Storage Areas be Inspected?
Storage areas should be inspected frequently to identify deteriorating containers and faded or missing labels
What are Control Areas and How do They Limit the Amount of Chemicals Stored in a Laboratory?
Control areas are spaces within a building, constructed with fire resistance and rated walls and floors, where quantities of hazardous materials not exceeding the maximum allowable quantity (MAQ) are:
- Dispensed; or
- Used or handled.
The Virginia Statewide Fire Prevention Code regulates the number of control areas permitted per floor and the required fire rating for walls separating control areas from each other, and other spaces not otherwise rated. The SFPC also determines the percentage of the MAQ of hazardous substances allowed per control area on each floor above and below grade.
The MAQ per control area is an administrative control method used to regulate the maximum amount of a hazardous materials allowed to be stored or used within a control area inside a building based upon the physical state of the material and relevant storage conditions. Storage and use of hazardous materials in quantities that exceed the MAQ per control area require specified hazard class building construction to accommodate the additional hazards. Use of hazardous materials in excess of the MAQ is not permitted in buildings without hazard class construction.
What Information is Required for a Chemical Container?
OSHA requires that each chemical container, regardless of size or use, to be properly labeled with:
- the complete chemical name (formulas, abbreviations, and sketches of the molecule are not acceptable),
- manufacturer’s information (if the chemical is in its original container),
- appropriate hazard information (words, pictures, symbols, or any combination thereof) that provides at least general information regarding the hazards of the chemical.
- secondary containers must be clearly labeled using the complete chemical name and associated hazards of the chemical. Chemical formulas or abbreviations are not permitted unless a legend is clearly posted in the area of use to identify the chemicals.
When are Dates Required for Chemical Containers?
Record the date received (for ordered chemicals) or the date generated (for chemical dilutions and experimental samples) on all containers to prevent excessive waste and ensure proper disposal of expired chemicals. Peroxide forming chemical containers must also be dated when opened so they can be disposed of within one year of opening to prevent formation of explosive peroxides.
Where to Place a Label on Chemical Containers
Labels should be securely attached to the side of the container, opposite of the spout when possible. Labels affixed to container lids or stoppers are not reliable for identifying chemicals because lids may inadvertently be switched during use.
Labeling Small Vessels and Experimental Samples
Experimental samples and small reagent vessels may be identified by an alphabetic, numeric, or alphanumeric label if this label and corresponding label information is provided in a log that lists the chemical name represented by each sample and the hazards associated with that chemical. Laboratory personnel should be aware of the log and the hazards associated with the samples.
What to do With Unlabeled Containers
Unlabeled containers must be assumed to contain hazardous components until the contents can be identified. Contact EHS, 3-8448 or firstname.lastname@example.org , for assistance in handling unlabeled containers.
Chemical Compatibility and Segregation
To prevent unwanted or dangerous chemical reactions, chemicals must be stored according to compatibility. Chemicals of the same hazard classification or functional group that share the same characteristics may be stored together. Incompatible chemicals must be segregated.
- SDS and container labels provide useful information regarding compatibility and storage requirements.
- Container labels may provide hazard symbols or list the hazards associated with the chemical (e.g., flammable, oxidizer, poison, toxic, corrosive, or reactive).
- The Chemical Compatibility and Segregation table provides general information about the primary hazard classes and chemical incompatibility. Reference this table when designing storage areas or determining segregation strategies.
- EHS is available to provide additional information and assistance with chemical segregation.
Chemical segregation can be accomplished using shelves, bins, cabinets, and other secondary containment equipment. Another way to reduce the potential for reactions between chemicals is to prevent contact by proximity. Storing solid oxidizing compounds on the opposite side of the laboratory from flammable liquids significantly reduces the possibility of contact. Acids and bases can be separated from one another by means of a divider or wall within a corrosive cabinet.