Characteristics
Over a period of time, these chemicals can form peroxides that may explode when the cap is removed or when they are concentrated during laboratory activities. It is important to note on the container the date the chemical arrived in the laboratory, when it was opened, when it should be tested for peroxide concentration, and when it should be discarded. Dispose of the chemical before the discard date indicated on the container or follow the guidelines below.
Dispose of within 24 Hours:
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acrylic acid (uninhibited)
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butadiene (uninhibited)
Test or Dispose of within 3 Months:
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butadiene (inhibited)
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chloroprene
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divinylacetylene
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isopropyl ether
Test or Dispose of within 12 Months:
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acetaldehyde
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acrolein
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benzyl ether
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2-butanol
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cyclohexanol
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diethyl ether
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ethyl vinyl ether
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2-hexanol
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3-methyl-1-butanol
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tetrahydrofuran
Storage and Disposal of Peroxide Forming Chemicals
By the expiration date, the owner/user should either dispose of the chemical or test it for peroxide content. Dispose of any chemicals found to have a peroxide concentration greater than or equal to 100 parts per million. (Call EH&S for assistance.) Materials that have lasted beyond the recommended shelf life but have been tested and show no detectable peroxides, or whose peroxide concentrations are less than 100 ppm, may be retained but should be tested at frequent intervals. Test all peroxide forming chemicals prior to distillation, regardless of age.
Important note: Never test containers of unknown age or origin. Old bottles are likely to contain concentrated peroxides, and peroxides may have crystallized in the cap threads, which can present a serious hazard when the bottle is opened for testing.
Contact ucbcho@berkeley.edu for help with managing older containers and for additional guidelines on the safe storage and handling of peroxide forming chemicals.
Storage Precautions for Peroxide Forming Chemicals
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Identify all peroxide forming chemicals in your inventory.
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Write the opening date and discard date on the containers of chemicals that may degrade to become potentially explosive.
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Store in airtight containers in a dark, cool, and dry place.
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Discard or test peroxide forming chemicals once expired. Contact EH&S for disposal information.
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Inspect peroxide forming chemicals often for evidence of contamination, degradation, or any change from normal physical or chemical characteristics. Contact EH&S immediately if you suspect a material shows signs of stratification, discoloration or crystal growth. Post warning signs so others do not handle or disturb the material.
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Note: Most explosions occur while purifying or distilling mixtures. Therefore, use extreme caution before concentrating or purifying any mixture that may contain an explosive chemical .
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For more extensive information regarding potentially explosive chemicals, please see the “Guidelines for Explosive and Potentially Explosive Chemicals Safe Storage and Handling”