7.1 GENERAL PROCEDURES

The following are minimum guidelines and apply to all laboratories using hazardous materials.

1. All containers of chemicals must be properly identified by permanently affixed labels that include the full chemical name and associated hazards of the chemical.
   
2. Storage of chemicals according to alphabetical order is not the best storage system as this may place incompatible chemicals next to one another, or may cause large containers to be stored on a top self. Instead, group the chemicals according to hazard class with larger containers near the bottom of the shelf.
   
3. All containers of flammable solvents larger than 1 liter shall be stored in approved metal storage cabinets. Flammables and strong oxidizers must be separated.
   
4. Containers of non-flammable chemicals and reagents should be stored in cabinets or on shelves provided for that purpose. Storage of acids and bases shall be segregated and stored near floor level.
   
5. Proper, skid-proof footstools or stepladders shall be used for reaching upper shelves. Do not stand on chairs or other easily movable objects.
   
6. Glass containers shall never be stored directly on the floor.
   
7. Return lab equipment, chemicals and miscellaneous items to their proper storage locations when no longer needed. Do not store chemical containers on bench tops.
   
8. Do not store items in a fume hood or biological safety cabinet.

7.2 HAZARDOUS MATERIALS

The following procedures are guidelines for laboratories using or storing hazardous materials.

1. The total inventory of flammable liquids in a laboratory must not be excessive. As a guide to acceptable quantities of stored chemicals, the National Fire Prevention Association (NFPA) has set limits for storage of flammable liquids in laboratories.

The following are storage limits established for Texas A&M-Kingsville laboratories:

Maximum individual container sizes for flammable liquids are 1 gallon for unprotected (I.e., exposed glass) containers and 5 gallons for metal safety cans.

No more than 5 gallons of flammable liquids may be stored in any individual laboratory in unprotected containers.

No more than 10 gallons of flammable liquids (total quantity in any type of container) may be kept outside of a flammable chemical storage cabinet.

2. Flammable chemical storage cabinets must meet OSHA CFR 1910.106 and NFPA 30 regulations, which is to be double-walled metal cabinets whose backs are securely bolted to a masonry or brick wall, if possible, to prevent tipping. The doors of these cabinets should have positive-catch latches (i.e., a handle must be turned, not merely pulled, to open the door).
   
3. Flammable chemicals requiring refrigeration must be stored only in approved explosion-proof refrigerators or freezers.
   
4. Substances with particularly noxious or toxic vapors must be stored inside a ventilated storage cabinet or, if necessary, in an operating fume hood. If the fume hood is also to be used for experimental work, then it should be provided with a separate metal cabinet for chemical storage.
   
5. Because of the possibility of formation of explosive peroxides, the storage of opened containers of ethers derived from primary and secondary alcohols, is particularly hazardous. The containers of peroxide forming chemicals (i.e., ethyl or isopropyl ether) should be labeled with the date they are first opened, and the entire contents shall be used or disposed of within 6 months after first opening the container. Unopened containers should be disposed after 12 months of storage. Examples of peroxide forming chemicals are listed in Appendix E.
   
6. Potential ignition sources, such as flames or non-explosion-proof electrical motors, are not allowed in areas where flammable chemicals are used or stored.
   
7. Incompatible chemicals, such as strong acids and bases, or strong oxidizing agents and organic reagents, must not be stored in close proximity.
   
8. Rubber bottle carriers or carts (available from the chemical stockroom) are required for transporting glass containers of chemicals in building corridors.

7.3 LABELS

The following guidelines pertain to chemical identification.

Date all chemical containers when the chemical is received and when first opened.

Label secondary containers to clearly identify its contents and the date it was prepared.

Do not use a chemical from an unlabeled container.

Label all containers, freezers, lab entrance doors and other locations as necessary to indicate specific hazards (e.g. "carcinogen", "biohazard").

7.4 WASTE CHEMICAL DISPOSAL

The following guidelines are procedures for disposing of hazardous materials.

1. In research laboratories, where many unusual chemicals are used, the responsibility for disposal of unused reagents and waste reaction products is that of the researcher or their faculty advisor, because in most cases only these individuals know how to handle the materials safely. The Environmental Health & Safety Office shall be contacted for disposal options.
   
2. Disposal of waste by drain will only be permitted for small quantities of water-soluble, non-regulated waste. This is providing that the waste will not hydrolyze to form volatile, toxic, or malodorous materials. Consult with the laboratory supervisor or the Environmental Health & Safety Office prior to pouring any chemical in the sink.
   
3. Acids and bases may be disposed by drain only after the material has been neutralized and there are no other hazardous constituents.
   
4. Regulated hazardous waste e.g., flammable liquid wastes must not be poured into sinks or other wastewater drains, but must be poured in approved containers. Laboratories that generate large volumes of regulated hazardous waste (exceeding 10-20 gallons per week), must pour the material in 5 gallon or 30 gallon containers, rather than in 1 gallon glass containers, prior to disposal.
   
5. A Waste Disposal tag must be attached to the container and should provide a list of the container's contents. Properly tagged waste containers should be periodically removed and placed in storage. Contact the Environmental Health & Safety Office for assistance with hazardous material disposal.
   
6. All empty chemical containers must be triple rinsed before discarding. The rinsate shall be collected and placed in a container according to hazard class (e.g. flammable rinsate, corrosive rinsate, etc.) for storage purposes. The labels of the empty container shall be marked out and the containers disposed of properly..

Mercury

All work involving metallic mercury should be performed over trays or pans with turned-up edges to confine any mercury which may be spilled.

Mercury spills must be carefully cleaned with a trapped vacuuming device. Contact the EHS Office in the event of a mercury spill at extension 2645.

Contaminated mercury must be stored in labled, closed bottles. Contact the Environmental Health & Safety Office for assistance with hazardous waste disposal.

7.5 CHEMICAL CLEAN-UP

1. To minimize the risk of a hazardous material spill transport the minimum amount of chemicals needed.
   
2. Dispose of excess or waste chemicals in appropriately LABELED WASTE CONTAINERS as directed by the laboratory supervisor.
   
3. Label all waste containers in a manner that "non-science" persons will know their contents.
   
4. As directed by the laboratory supervisor, flush SMALL AMOUNTS of approved liquid chemicals down the drain with copious amounts of water.
   
5. Place broken glass in designated containers.
   
6. Clean up minor spills with paper towels and water. For major spills, under the supervision of the lab instructor, use appropriate spill control and containment equipment and contact the Office of Environmental Health & Safety at extension 2645.
   
7. Sulfur or a mercury spill kit must be used to contain mercury if there is a mercury accident such as a broken mercury thermometer.

Return to Table of Contents                                        Go to Next Section