Chemical Segregation and Storage Guide
Chemical segregation and storage practices are critical to preventing accidents and harmful outcomes that can occur when chemicals are stored improperly. Use this guide to help protect your staff and facilities and maintain compliance with regulations.
Chemical Examples
Storage Recommendations
Incompatible Chemical Types
Reactions if Mixed and Health Precautions
Corrosive Organic Acids 
- Acetic Acid
- Butyric Acid
- Glacial Acetic Acid
- Picric Acid
- Propionic Acid
- Trifluoroacetic Acid
- Use ventilated safety cabinet
- Store using protected shelving with secondary containment
- Keep away from water
- DO NOT store under sink or on metal shelving
- Bases
- Cyanides
- Flammable Liquids
- Flammable Solids
- Inorganic Acids
- Oxidizers
- Poisons or Toxins
- Sulfides
- Violent and exothermic reactions
- Gas generation
- DO NOT allow water to mix with acid
Corrosive Inorganic Acids 
- Concentrated Nitric (≥68%) and Sulfuric Acids (≥93%) should be stored in secondary containers
- Use a safety cabinet labeled “Acid” or on protected shelving using secondary containment
- DO NOT store under sink or on metal shelving
- Store Hydrofluoric Acid where accessible only by authorized personnel
- Use plastic containers and secondary containment — DO NOT store in glass
- Consult Division of Environmental Protection (DEP) for assistance
- Bases
- Cyanides
- Flammable Liquids
- Flammable Solids
- Organic Acids
- Oxidizers
- Poisons or Toxins
- Sulphides
- Violent and exothermic reactions
- Gas generation
- DO NOT allow water to mix with acid
- Perchloric Acid vapor has the potential to form explosive compounds
Caustic and Corrosive Organic Bases 
- Hydroxylamine
- Tetramethylethylamine
- Diamine
- Triethylamine
- Use separate cabinet — ventilated corrosive cabinet recommended or area with spill tray
- Keep away from potential water sources
- DO NOT store under sink
- Acids
- Flammable Liquids
- Flammable Solids
- Inorganic Bases
- Oxidizers
- Poisons or Toxins
- Violent and exothermic reactions
- Gas generation
Caustic and Corrosive Inorganic Bases 
- Ammonium Hydroxide
- Calcium Hydroxide
- Potassium Hydroxide
- Sodium Hydroxide
- Use separate cabinet — ventilated safety cabinet recommended or area with spill tray
- Keep away from potential water sources
- DO NOT store under sink
- Use labeled polyethylene containers for solutions of inorganic hydroxides
- Acids
- Flammable Liquids
- Flammable Solids
- Organic Bases
- Oxidizers
- Poisons or Toxins
- Violent and exothermic reactions
- Gas generation
Flammable Solids 
- Carbon
- Charcoal
- Magnesium
- Paraformaldehyde
- Phosphorus
- Store in a dry, cool area and away from oxidizers and corrosives
- Acids
- Bases
- Oxidizers
- Poisons or Toxins
- Violent and exothermic reactions
- Fire hazard
Flammable Liquids 
- Acetone
- Acetone solutions with flashpoints <100°F
- Acetonitrile
- Benzene
- Diethyl Ether
- Ethanol
- Ethyl Acetate
- Glacial Acetic Acid
- Methanol
- Tetrahydrofuran
- Toluene
- Xylene
- Use flammable safety cabinet or flammable and explosion proof refrigerators
- Record receipt and open dates for any peroxide-forming chemicals
- Acids
- Bases
- Oxidizers
- Poisons or Toxins
- Reactives
- Violent and exothermic reactions
- Fire hazard
Poisons or Toxins 
- Acrylamide
- Chloroform
- Cyanides
- Ethidium Bromide
- Heavy Metal Compounds: Cadmium, Mercury, Osmium, Oxalic Acid, Phenol, Formic Acid, Formamide
- Hydrofluoric Acid
- Sodium Azide
- Store in a dark, dry, ventilated, and cool area
- Use unbreakable chemically resistant secondary container (polyethylene)
- Store volatile toxins with evaporation rate above 1.0 - (ether =1.0) in a flammable cabinet
- Store non-volatile liquid poisons in a refrigerator or cabinet
- Store amounts less than 1 L in above bench level cabinets ONLY when the cabinet has sliding doors
- Store Hydrofluoric Acid where accessible only by authorized personnel
- Use plastic containers and secondary containment — DO NOT store in glass
- Consult DEP for assistance
- Acids
- Bases
- Corrosives
- Flammable Liquids
- Oxidizers
- Reactives
- Violent and exothermic reactions
- Toxic and flammable gas generation
- Combustion and fire hazard
- Explosion hazard
- Chloroform decomposes in sunlight and explosively reacts with chemically-reactive metals:
- Aluminum or Magnesium Powder
- Sodium and Lithium
- Strong Oxidizers
- Strong Caustics such as Alkalis
Explosives 
- Ammonium Nitrate
- Benzoyl Peroxide
- Diazoisbutylnitrile
- Nitro Urea
- Picric Acid
- Trinitroaniline
- Trinitrobenzene
- Trinitrobenzoic Acid
- Trinitrophenol
- Trinitrotoluene
- Urea Nitrate
- Secure and store away from other chemicals
- Keep away from friction or shock
- Consult Safety Data Sheet (SDS)
- Consult DEP
- Violent and exothermic reactions
- Gas generation
- Explosion hazard
Oxidizers 
- Store separately from combustibles and flammable materials
- Use secondary containment
- Combustibles
- Flammables
- Organic Materials
- Reducing Agents
- Fire hazard
- Toxic gas generation
Peroxide Formers 
- Acetals
- Acrylonitrile
- Aldehydes, including Acetaldehyde and Benzaldehyde
- Butylated Hydroxytoluene (BHT)
- Compounds
- Cyclic Ethers and those with primary or secondary Alkyl groups
- Dienes Tetrahydrofuran
- Diethyl Ether
- Dioxane
- Isopropyl Ether
- Ketals, including secondary Alkyl groups
- Vinyl and Vinylidene
- Keep away from light and heat
- Store in airtight bottles
- Avoid containers with loose-fitting lids and ground glass stoppers
- Record receipt and open dates for any peroxide-forming chemicals
- Crystallization, discoloration, and formation or deposition of layers are signs of shock sensitivity — DO NOT use or move such containers, contact DEP
- DO NOT handle old or expired containers of peroxide-forming chemicals or reactives. Contact DEP at 301-496-4710
- Consult SDS
- Consult DEP
- Exothermic and violent reactions
- Explosion hazard
- Shock sensitivity
- Combustion risk
Water Reactive 
- Aqueous Solutions
- Oxidizers
- Consult SDS
- Consult DEP
- Exothermic and violent reaction
Flammable Compressed Gases 

- Acetylene
- Arsine
- Butane
- Ethane
- Germane
- Hydrogen
- Methane
- Propane
- Silane
- Store in well-ventilated area
- Store away from oxidizers, open flames, sparks, and other sources of heat ignition
- Keep out of direct sunlight if storing outdoors where ambient temperatures exceed 125°F or 51.7°C
- Use a non-sparking wrench to attach regulators and other connections
- Install a flame and flash arrestor at the regulator outlet flow valve
- Post NO SMOKING signs around storage areas and entrances
- Use a chemical fume hood to handle flammable compressed gases
- Oxidizers
- Toxic Compressed Gases
- Fire hazard
- Explosion hazard
Oxidizing Compressed Gases 

- Chlorine
- Fluorine
- Gas mixtures containing Oxygen levels higher than atmospheric concentrations
- Nitrogen Oxides
- Oxygen
- Store oxidizers separately from flammable gas containers and combustible materials
- Minimum separation requirement is 20 ft. or 5 ft. for a noncombustible barrier with a minimum fire resistance rating of 30 minutes
- Equipment used for Oxygen and Nitrous Oxide with Oxygen-Compatible materials should be cleaned with materials free from oils, greases, and other contaminants
- Handle Fluorine in specially passivated containers and associated equipment
- Flammable Compressed Gases
- Toxic Compressed Gases
- Fire hazard
- Explosion hazard
Toxic Compressed Gases 

- Carbon Monoxide
- Hydrogen Chloride
- Hydrogen Sulfide
- Nitrogen Dioxide
- Use a chemical fume hood when handling toxic compressed gases
- Use a gas cabinet, exhausted enclosure, or gas room for indoor storage or use of toxic compressed gases
- Refer to SDS information for additional guidance
- Contact Division of Occupational Health and Safety (DOHS) to determine if a failsafe valve or continuous monitoring for toxic gas may be required
- Flammable Compressed Gases
- Oxidizing Compressed Gases
- Release of toxic gas
- Prolonged exposure to Hydrogen Sulfide may cause nausea, eye tearing or conjunctivitis, headaches, loss of sleep, bronchial constriction, fatigue, loss of appetite, headache, irritability, poor memory, and dizziness
Strong Reducing Agents 
- Keep segregated from all other chemicals
- Take water-reactive precautions
- Store in a well-ventilated, cool, dry, location
- Consult SDS
- Consult DEP
- Consult SDS
- Consult DEP
Carcinogens 
- Benzene
- Benzidine
- Beta-Naphthylamine
- Beta-Propiolactone
- Carbon Tetrachloride
- Methylene Chloride
- Use "Cancer Suspect Agents" label or equivalent on all containers
- Store according to the hazardous nature of the chemical
- Use appropriate security
- Consult SDS
- Consult DEP
- Consult SDS
- Consult DEP
Teratogens 
- Aniline
- Benzene
- Lead Compounds
- Mercury Compounds
- Use "Suspect Reproductive Hazard" or “Reproductive Effecter” label on all containers
- Secure and store according to the hazardous nature of the chemical
- Aniline is incompatible with Nitric Acid and Hydrogen Peroxide
- Consult SDS
- Consult DEP
- Consult SDS
- Consult DEP
General Stock Chemicals 
- Agar
- Most Non-Reactive Salts
- Salt Buffer
- Sodium Bicarbonate
- Sodium Chloride
- Consult SDS
- Consult DEP
- Consult SDS
- Consult DEP
Source: National Institute of Health Chemical Segregation and Storage Table https://ors.od.nih.gov/sr/dohs/Documents/General_Chemical_Storage_Compatibility_Chart.pdf