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Chemical storage

BACKGROUND

      Fire and explosion are only two of the many hazards.

      Over 500 chemical-storage incidents were over the past 5 years.

      These incidents occurred due to unsafe chemical storage practices.

Storage-related incidents

      Principal causes:

      1. Improper or non-existent labeling of chemicals in storage.

      2. Storage of chemicals beyond the recommended shelf-life.

      3. Degradation of chemical storage containers. ("Polyethylene Bottles Containing Corrosive Chemicals May Deteriorate With Prolonged Use,"

IMPROPER LABELING

      Small amounts of "left-over" chemicals had accumulated over several years.

      The chemicals were prepared for recycling or disposal by removing the chemicals from their individual containers and putting them into a plastic bucket.

      Powder that was thought to be a base material was poured from an unlabeled jar into the bucket, resulting in spontaneous ignition.

      The building then had to be evacuated, and the fire department was summoned to put out the fire.

      Analysis performed by the laboratory later revealed that the powder was maleic anhydride,

EXTENDED TIME IN STORAGE

      During a site-wide Occupational Safety and Health Administration (OSHA) label audit industrial hygienists

      found a total of 21 containers of ether which had been stored for over 2 years.

      .Unrefrigerated ether cannot be stored safely for over 6 months because peroxides, which are shock-sensitive, can form and cause an explosion.

      The building that housed the 18 ether containers had to be evacuated, and barricades had to be assembled to protect flammable inventory.

      The peroxides were then neutralized with ferrous sulphate, and all 21 containers were removed.

      Periodic inspection and removal of outdated chemicals in storage would have prevented the incident.

Storage rules

           Label all chemicals. The name and address of the manufacturer or other responsible party must be listed on the label. Chemicals with a shelf life should be labeled with the date received.

           Store chemicals in the locations recommended (i.e., where the temperature range, vibration, or the amount of light does not exceed the manufacturer's recommendations). Make sure that chemicals that are stored together are compatible.

Storage rules

3. Inspect annually all chemicals in stock and storage.

4. Hazardous chemicals should be inspected every 6 months.

5. Some hazardous chemicals may require more frequent inspections.

6. Any outdated materials should be properly disposed of or replaced if necessary

Rules

7. Keep only enough inventory necessary for uninterrupted operation.

8. Chemical inventory should be maintained at a minimum to reduce fire, exposure, and disposal hazards

9. Rotate new shipments of chemicals with existing stock so that the oldest stock is available first.

Storing Acids

      Store large bottles of acids on low shelf or in acid cabinets.

      Segregate oxidizing acids from organic acids, flammables and combustible materials.

      Segregate acids from bases and active metals such as sodium, potassium, etc.

      Use bottle carrier for transporting acid bottles.

      Have spill control pillows or acid neutralizers available in case of spill.

 

Strong Oxidizing Acids

      Chromic Acid

      Nitric Acid

      Hydrobromic Acid

      Perchloric Acid

      Iodic Acid

      Sulfuric Acid

Organic Acids

      Acetic Acid

      Phenol

      Benzoic Acid

      Trichloracetic Acid

Storing Bases

      Segregate bases from acids

      Store solutions of inorganic hydroxides in polyethylene containers.

      Have spill control pillows or caustic neutralizers available for spills.

Bases

      Ammonium Hydroxide

      Calcium Hydroxide

      Bicarbonates

      Potassium Hydroxide

      Carbonates

      Sodium Hydroxide

Flammable

      Store in approved safety cans or cabinets

      Segregate from oxidizing acids and oxidizers.

      Keep away from any source of ignition: flames, heat or sparks.

      Know where fire fighting equipment is stored and how to use.

      If volatile flammable liquids are stored in a refrigerator it must be in an explosion-proof (lab-safe) refrigerator.

 

Flammable Solids

      Benzoyl peroxide

      Phosphorous, yellow

      Calcium Carbide

      Picric Acids

Flammable Gases

      Acetylene

      Ethylene Oxide

      Ammonia

      Formaldehyde

      Butane

      Hydrogen

      Carbon Monoxide

 

Storage of Oxidizers

      Store in a cool, dry place.

      Keep away from flammable and combustible materials, such as paper or wood.

      Keep away from reducing agents such as zinc, alkaline metals, formic acid.

 

Oxidizers - Solids

       Ammonium Dichromate

       Nitrates

       Ammonium Perchlorate

       Ammonium Persulfate

       Benzoyl Peroxide

       Bromates

       Calcium Hypochlorite

       Chlorates

       Chromium Trioxide

       Ferric Trioxide

       Ferric Chloride

      Hypochlorite

      Iodine

 

 

 

 

 

 

 

 

 

Pyrophoric Substances:

       These ignite spontaneously on contact with air. Store in a cool, dry place.

 

 

Light Sensitive Chemicals

      Avoid exposure to light & Store in amber bottles in a cool, dry place.

 

 

Carcinogens

      Label all containers as Cancer Suspect Agents.

      Store according to hazardous nature of chemicals, e.g., flammable, corrosive.

      When necessary, store securely.

 

Carcinogens

      Antimony compounds

      Acrylonitrile

      Arsenic compounds

      Benzene

      Benzidine

      Chloroform

      Beryllium

      Dimethyl Sulfate

 

Chemical Segregation and Storage Groups

      Stanford Storage Group Classification System

      used to segregate chemicals stored in the laboratory.

      It is based on physical and chemical reactivity information found in the MSDS or other references.



Storage Groups

      Storage Groups are groups of chemicals that will not react violently if mixed together.

      Stanford has about 10,000 unique chemicals classified according this system in the SCIMS Database.

      The Stanford Storage Group system was developed for laboratory scale storage

 

STANFORD COMPATIBLE STORAGE GROUP CODES

      A letter designation is given to each compatible group of materials.

      For example, "A" represents "compatible organic bases, flammables and poisons".

      "G" is "not intrinsically reactive, flammable or combustible".

      A chemical that is incompatible with other chemicals in all of the other Storage Groups must be placed in Storage Group "X". Storage Group "X" chemicals must be segregated from all other chemicals.

      If the information is not available, then Storage Group "U" will be assigned.

 

SEGREGATE CHEMICALS BY COMPATIBLE STORAGE GROUPS

      Segregate chemicals in a compatible fashion according to the compatible Storage Groups.

      If a particular item does not yet have a storage group designated, the researcher must use his best judgement on how best to store the material.

      Keep the different storage groups in separate cabinets, if possible.

 

 

SEGREGATE CHEMICALS BY COMPATIBLE STORAGE GROUPS

      In areas that contain items from more than one storage group, there is no need to store them alphabetically by storage group (i.e. A then B then C). The letters are just an arbitrary convention.

 

SEGREGATE CHEMICALS BY COMPATIBLE STORAGE GROUPS

      If you must store items from more than one storage group on the same shelf, they must have separate secondary containment for each group.

      For example:

   Acetic acid (Storage group "D", organic acid)

   Hydrochloric acid (Storage group "F", inorganic acid)

   Nitric acid (Storage group "E", oxidizing)

      These all acids but they are incompatible and must be stored in separate secondary containment and on separate shelves within the same cabinet.

SEGREGATE CHEMICALS BY COMPATIBLE STORAGE GROUPS

SEGREGATE CHEMICALS BY COMPATIBLE STORAGE GROUPS

 

Store in same cabinet

      If you must store items from many storage groups in the same cabinet with more than one shelf,

      put storage group "B" and "X" on the top shelf.

      This will prevent other chemicals from dripping on them.

Flammable liquid storage

      If the total quantity of flammable liquids exceeds 5 Lt, they must be stored in a flammable liquid storage cabinet except when in active use.

 

OTHER STORAGE CONSIDERATIONS:

      Long-term storage on bench tops or in fume hoods is discouraged.

      All containers MUST remain closed except when actively adding or removing materials. Do not store funnels in open containers.

      Never store hazardous materials next to or above sinks. This includes dark rooms with waste fixer stored adjacent to open floor drains.

OTHER STORAGE CONSIDERATIONS:

      Store solids above liquids.

      Avoid exposing stored chemicals to building heat or to direct sunlight.

      All chemical storage shelving must have lips and seismic restraints.

      Use explosion-proof refrigerators when storing flammables in a refrigerator.