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Proper Management of Chemicals

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Overview of Managing Your Chemicals

4. Managing Your Chemicals

As chemical requesters and users, we all share the responsibility to ensure hazardous chemicals and gases are properly acquired and managed throughout their lifecycle  

Maintaining accurate inventory in the Lab’s CMS system is key to safety and compliance.  Tutorial videos are available on how to edit containers, transfer ownership, mark containers as disposed/used up, and perform chemical inventory reconciliation.  Below you will find additional information on the required aspects of managing your chemical inventory.

Chemical Storage and Segregation

  1. Store hazardous chemicals in proper storage areas, such as flammable and corrosive storage cabinets 

These storage areas are designed to minimize the consequences of an off-normal event such as a fire or broken/leaking container. 

  1. Ensure incompatible materials within each storage area are adequately segregated to prevent inadvertent mixing.  Nitric acid requires its own dedicated secondary containment and must be segregated from all other acids. 

If you are a chemical user, it is important to plan for safe storage prior to acquiring hazardous chemicals and to monitor storage areas for issues and signs of incompatibility such as rust or chemical residues.  Report these warning signs to a responsible person like the chemical owner, or your Division Safety Coordinator. 

Related Resources

Chemical Storage website:  Storage basics, requirements, and resources such as printable segregation posters. 

Chemical Inventory

Having an accurate site-wide chemical inventory is crucial for safety and science. At LBNL,  hazardous chemicals and gases are tracked in the CMS database.  

The chemical owner (usually a PI or technical area supervisor) is ultimately responsible and accountable for maintaining an accurate inventory, which means ensuring all hazardous materials are tracked accurately in CMS and disposed in CMS when the materials have been used up, disposed, or taken off-site. Facilitating proper storage and mitigation of hazards such as time-sensitive chemical management are also key responsibilities. 

Samples and Secondary Containers (a.k.a. splits or child containers)

Research samples and secondary containers of hazardous materials (also known as splits or child containers) are a necessary aspect of research activities at Berkeley Lab, but have resulted in substantial challenges when not labeled and managed properly. The following requirements support hazard communication and chemical lifecycle stewardship:

  • Identify non-hazardous samples/splits with content identification, at minimum
  • Hazardous samples/splits require content identification and hazards (words, pictures, symbols, etc.)
  • Time-sensitive  samples/splits have the same requirements as their primary containers (RFID tagging, CMS tracking, and assessment/testing)
  • Use compatible materials, and more durable materials for longer term storage
  • Do not keep samples/splits for longer than necessary – space is a premium!
  • Samples must be properly disposed when they are no longer needed or prior to leaving LBNL unless long term storage arrangements are made 

Supporting Resources: 

Peroxide-Forming Organic Solvents

Peroxide-forming organic solvents are commonly used in the laboratory for a wide variety of purposes. It is important to properly manage these chemicals to prevent incidents and high disposal costs. Here are some strategies you can use keep your peroxide-forming organic solvents from becoming a problem for you and your Division. 

Purchase Wisely

Unused peroxide-forming solvents become very difficult to dispose if their peroxide concentration reaches 20ppm or greater. The longer you keep a container, the more likely it is to exceed that threshold.

  • Purchase only what you expect to use in the next 3-12 months, especially if you are using a Class A peroxide-forming chemical such as isopropyl ether.
  • Purchase containers with inhibitor to keep peroxide levels low for as long as possible. Note that inhibitors become depleted over time, so it’s still important not to over-buy.
  • If you’re not sure if the chemical will work for you, borrow a small amount from another group before committing to purchasing your own container. 

Track Your Inventory

  • Enter your peroxide-forming organic chemicals into CMS as soon as you receive them.
  • Attach a peroxide-forming chemical label.
  • Fill out the date received and testing interval on the peroxide-forming chemical label immediately.

With accurate records in CMS, the chemical owner will receive reminders about peroxide testing. 

Test Frequently

The more often you test your solvent, the more likely you are to notice the peroxide levels creeping up before they get too high.

Intervene Early

There are products that can actively and continuously reduce peroxides in your container, as well as purification techniques that can be used to remove peroxides. These should be employed early to keep your container as close to peroxide-free as possible for its entire lifetime.

Requirements:

Before using one of the methods below, make sure the following requirements are met.

  • The container passes visual pre-inspection.
  • The container is not a hazardous waste or intended for immediate disposal.
  • The peroxide concentration is less than 100ppm. Containers with greater than 100ppm peroxides are not safe to handle and use.
  • You are adequately trained and authorized to perform this work. You are on an Active WPC Activity that authorizes you to work with peroxide-forming organic chemicals and to perform the specific procedure you have chosen to use; You have taken all required online safety training; You have received specific on-the-job training for the work; You are following the controls outlined in your WPC Activity.
  • You have researched the method to ensure there will be no chemical compatibility issues or other safety concerns. Consult with the chemical safety team if you need assistance.

Methods:

  • Activated basic alumina(1): Up to 700 mL of solvent are passed through a 2 x 33 cm column filled with ~80 g of 80-mesh basic activated alumina. Test for peroxides and repeat this process if necessary to reach an acceptable peroxide concentration. For low levels of peroxides ( < 10 ppm) a short plug of basic activated alumina may be sufficient. This method is quite advantageous as it is rapid, does not introduce moisture or peroxide decomposition products, and uses readily available lab equipment. The activated alumina column should be disposed of with care, as some peroxides may remain unchanged after adsorption. A saturated solution of ferrous sulfate or potassium iodide may be passed through the alumina column to ensure that all adsorbed peroxides are completely destroyed.2
  • Aqueous sodium metabisulfite(2): This method is appropriate for water-insoluble organic solvents. The solvent is washed with a freshly prepared dilute aqueous solution of sodium metabisulfite (Na2S2O5, 5%), 10:1 v/v. Use care to prevent pressure buildup (no closed containers), particularly with low-boiling point solvents like ethyl ether, as an appreciable temperature increase may result upon mixing (~10 degrees F). Separate the organic phase. The organic phase can be dried over a suitable drying agent, if desired.
  • Ferrous sulfate solution(3,4): This method is appropriate for water-insoluble organic solvents. A saturated solution of ferrous sulfate is freshly prepared by mixing 120 g ferrous sulfate (the heptahydrate, FeSO4 • 7H2O is commonly used), 12 mL concentrated sulfuric acid, and 220 mL distilled water. The solvent is extracted with the ferrous sulfate solution several times until peroxides are no longer detected. This method is generally quite effective and fast. The organic layer is separated, washed with water twice, then dried over sodium or magnesium sulfate.
  • Indicating molecular sieves5: Indicating molecular sieves (blue-colored) have been reported to reduce peroxide concentration to acceptable levels in a variety of peroxidizable organic solvents. This method is convenient, dries the solvent, and does not introduce contamination or byproducts. However, this method may be less effective than other techniques, and peroxide removal is generally quite slow at room temperature. Refluxing the solvent over indicating molecular sieves substantially decreases peroxide removal time.
  • Commercial products for peroxide-forming chemicals6: Commercial products are available for continuous removal of peroxides in peroxide-forming chemicals. These products can be added directly to the original manufacturer’s container to prevent formation of peroxides. Chemical owners may wish to purchase these products for use in their labs.

References:

(1) Dasler, W. and Bauer, C. D.; “Removal of Peroxides from Organic Solvents” Ind. and Eng. Chem. 1946,18, 52-54.

(2) Hamstead, A.C.; “Destroying peroxides of isopropyl ether” Ind. Eng. Chem. 1964, 56, 37-42.

(3) Mifafzal, G. A. and Baumgarten, H. E.; “Control of Peroxidizable Compounds: An Addendum” J. Chem. Ed. 1988, 65, A226-A229.

(4) Jackson, H. L. et. al; “Control of Peroxidizable Compounds” J. Chem. Ed. 1970, 47, A175.

(5) Burfield, D. R.; “Deperoxidation of Ethers. A Novel Application of Self-Indicating Molecular Sieves” J. Org. Chem. 1982, 47, 3821.

(6) “XPell™ indicating pellets for peroxides prevention, CE for organic solvents” by XploSafe (Part Number 3002) is available directly through their website, as well as from Sigma (Z683299-1EA), Amazon, etc.

(7) Perrin, D. D., W. L. F. Armarego, and Dawn R. Perrin. Purification of Laboratory Chemicals. Oxford: Pergamon Press, 1980.

(8) National Research Council. 1995. Prudent Practices in the Laboratory: Handling and Disposal of Chemicals. Washington, DC: The National Academies Press. https://doi.org/10.17226/4911. Refer to Section 7.D.2.5: “Organic Peroxides and Hydroperoxides.”

(9) Kelly, R. J.; “Review of Safety Guidelines for Peroxidizable Organic Chemicals” Chem. Health and Safety 1996, September/October, 28-36.

 

Additional Time-Sensitive Chemicals

There are a number of additional time-sensitive chemicals used in the laboratory for a wide variety of purposes. It is important to properly manage these chemicals to prevent incidents and high disposal costs. 

Purchase Wisely

Unused time-sensitive chemicals become very difficult to dispose if they are not properly managed. The longer you keep a container, the more likely it is to develop unsafe conditions and exceed specifications for waste acceptance such as inhibitor concentration, age/expiration date, or visual appearance.

  • Purchase only what you expect to use in the next 3-12 months, especially if you are using monomers such as styrene, inorganic peroxide-forming chemicals: potassium metal, or explosive-when-dry chemicals such as ethyl diazoacetate.
  • For monomers, purchase containers with inhibitor to keep peroxide levels low for as long as possible. Note that inhibitors become depleted over time, so it’s still important not to over-buy.
  • If you’re not sure if the chemical will work for you, borrow a small amount from another group before committing to purchasing your own container. 

Track Your Inventory

  • Enter your time-sensitive chemicals into CMS as soon as you receive them.
  • Attach a time-sensitive chemical label.
  • Fill out the date received and assessment interval on the time-sensitive chemical label immediately.
  • Record the date opened and assessment results in CMS. It is recommended to also record this info on the label.

With accurate records in CMS, the chemical owner will receive reminders about assessments/testing. 

Assess Chemicals at Least Annually

Each class of time-sensitive chemicals has unique assessment criteria. Each container must be visually inspected and assessed at least annually. 

 

Transitioning Chemical Inventories to New Owners

What do you do with your chemicals and samples when you leave the Lab or change positions?

Chemical owners and users have responsibilities for the safety of all involved. Historically, when a chemical owner left the Lab, responsibilities for either disposing of or transferring their chemicals to a new owner were not well defined. This resulted in a number of unsafe conditions: expired time-sensitive chemicals, new owners without awareness of the high-hazard chemicals transferred to them, and gradual accumulation of chemicals that are neither used nor disposed as waste. Changes to policy and procedures were made to address these “legacy” chemical issues and to support effective chemical lifecycle stewardship. 

Learn more about the new policy here.

Related Resources

Chemical cleanout procedure:  Maintain accuracy of the inventory before, during, and after a cleanout 

← Back to Overview of Chemical Lifecycle Stewardship

Next step: Chemical Receiving Process →

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