Section 4: Waste Minimization and Pollution Prevention

University employees are tasked with many different responsibilities and perform many different operations from research to facilities maintenance. An important function in all of these operations is waste minimization. This portion of the Manual is written to provide employees with information that may help institute waste minimization methods in an easy and efficient manner. Minimizing waste may, in fact, simplify other tasks, such as proper management of chemical waste, making waste determinations and dealing with chemical inventories. These tasks will be streamlined by adopting proper waste minimization techniques in your processes.

Waste Minimization is often a method to obtain significant cost savings in chemical usage and disposal.  Another important aspect of waste minimization is that it helps to minimize the hazards presented by the use of dangerous chemicals. By minimizing the number of chemicals stored and the hazards associated with the chemicals, an area can greatly reduce the associated risks. It is also important to remember that “waste minimization” is required by federal and state law.


Purchasing Chemicals

All University employees that purchase chemicals (whether they are laboratory research chemicals, paint, solvents or cleaning compounds) should review their processes to ensure that they are only ordering as much chemical as they are going to use in the process.
As a result, the amount of chemical waste left over from the process will be reduced and associated inventories will shrink. This procedure should eliminate the disposal of any chemicals that have expired (per their shelf life date) and chemical storage will be easier with the smaller chemical inventory.

Steps to take to optimize chemical purchases:

  • Select a supplier who will support your waste minimization efforts (for example, will work to help you find suitable alternatives where warranted, which are less hazardous, or will sell smaller quantities).
  • Select a supplier who can deliver small amounts of chemicals on short notice and who will accept unopened chemicals that are returned.
  • Institute a centralized chemical purchasing system. Chemicals may be purchased in bulk (usually at a discounted price) by the centralized facility then distributed in proper sizes (amount needed for the process) to the laboratories. This would reduce waste and the amount of chemicals that have expired (per their shelf life date).  This would also eliminate redundant purchases and consolidate purchase orders.
  • Develop an “Authorized Use List” which suggests alternative “environmentally friendly” chemicals to replace hazardous chemicals.

Managing Chemical Inventories

Effective management of chemical inventories can reduce the cost and quantity of hazardous waste disposal. By effectively managing chemical stocks, a manager can prevent unwanted occurrences such as “unknown” chemicals, duplicate purchases, expired chemicals, and excessive inventory. Areas, which use and store chemicals and chemical waste, should follow the guidelines in the University Chemical Hygiene Plan. Labels must be maintained in a legible state and must include the chemical name, formula and percentage (in the case of mixtures). Labels may also include the location and responsible person’s name.

Steps to take to properly manage chemical inventories:

  • Chemicals should be stored by compatibility with incompatible materials separated by impermeable barriers.
  • Containers must be stored in a manner to prevent rupture or breakage.
  • Use a temperature controlled, dry area for the storage of the chemicals and ensure that the labels are legible and facing out.
  • Store chemicals at the proper temperature as noted on the label.
  • Inspect the chemicals and the storage area on a routine basis to ensure that there are no spills, leaks, or broken containers.
  • Inspect the inventory on a routine basis to ensure that the chemical stock is being used properly and discard materials which are not being used.
  • Track the materials that are purchased and their expected shelf life.
  • Identify the frequency of which each chemical is used
  • Dispose of material as shelf life expires.
  • Identify chemicals for exchange with other researchers or for EHSS’s Excess Chemical Exchange program.
  • Reduce quantities purchased so that chemicals are completely used before they expire to minimize needless waste.
  • Do not accept donations of chemicals, chemicals left from a previous researcher or other orphan materials.
  • EHSS will work with areas on a case by case basis to review donated chemicals prior to the University accepting them.

Conducting Waste Minimization Activities

This section presents some of the methods that can be taken to minimize wastes created as a result of experimentation. Some are very basic concepts that with some effort to be efficient and careful with procedures can substantially reduce the amount of waste generated.

Steps to take to minimize wastes created:

  • Teach, and practice, resource-efficient procedures
  • Plan and perform work with consideration of waste minimization
  • Encourage research of waste minimization techniques
  • Perform reduced scale chemistry
  • Substitute less hazardous materials into the process whenever possible
  • Explore alternatives to wet chemistry
  • Consider making precipitation and neutralization as part of the process

Treatment of Hazardous Waste

Neutralization of acids and bases is very common and widely accepted. Corrosive waste may be neutralized as long as there are no other associated hazards with the materials. If the material is “hazardous” due to being toxic, ignitable, reactive or contains any one of the “listed “ hazardous wastes as well as corrosive, the material may not be neutralized, and must be collected as a hazardous waste. Remember dilution is not neutralization and is not an acceptable method of neutralization. Also remember that the neutralization procedure must be done in small batches and that the waste may not be transported from one area to another for batch neutralization.

Neutralization/Drain Disposal

Any material with a pH of less than 5.5 and greater than 9.5 CAN NOT be drain disposed. A material which exhibits ONLY the characteristics of a corrosive waste may be neutralized and drain disposed as part of the process assuming:

  • The final pH prior to drain disposal is between 5.5 and 9.5
  • The waste does not contain a “listed” hazardous waste, is not ignitable, reactive, and/or toxic
  • A neutralization process was followed, (EHSS must approve the process prior to use.)
  • A record is created documenting:
  • The amount of material neutralized
  • The contents of the material neutralized
  • The final pH of the neutralized material
  • The date it was neutralized
  • The name of the person performing the neutralization process
  • The record is maintained on file and is available upon request for inspection.
  • Neutralization must be performed in small batches at the same site the waste was generated. Waste may not be moved from one area to another for batch neutralization.

Corrosive waste which is not neutralized must be collected as a regulated hazardous waste.

Precipitation of heavy metals is also an accepted form of on-site treatment. Materials which are hazardous due to their concentration of heavy metals may be treated to precipitate the metals out. The metals must be collected as a hazardous waste and the remainder of the material may be drain disposed or disposed of in the municipal solid waste as long as it does not present any other hazards.

There are other forms of treatment that are available. However, these forms of treatment should not be used unless approved by EHSS (see “Documentation of Waste Minimization” section on page 21 of this Manual) to ensure compliance with local, state and federal regulations. These forms include separation, fixation, oxidation, degradation, and ion exchange.


Reusing and Recycling Waste Minimization Methods

  • The College of the Redwoods has designed a series of “closed loop” experiments where the by-products of one experiment become the reagents/reactants of the next experiment. Recovery “in process” can be an important waste minimization tool. Recovery can be used as part of the process to return some chemicals to a state in which they may be used as product in another experiment or in a different process.
  • Solvent recovery is a simple and a cost effective example of recovery that may take place in the laboratory.
  • Chemical exchanges are another important part of waste minimization. EHSS operates an Excess Chemical Exchange program in which unused or under used chemicals that are in good condition or unopened are collected by EHSS for redistribution. These materials (when available) are listed on the EHSS website and the materials are stored in the main hazardous waste storage/accumulation area located in the Center for Science and Technology building. Upon request EHSS will deliver the material, the SDS, and will update the chemical inventory for the area requesting the material.

Please contact EHSS to schedule a time to meet and review waste minimization opportunities in your area. EHSS would be happy to work with laboratories and other areas to institute successful waste minimization techniques. Please contact EHSS with any success stories as well so that we may record and share any successes.


Documentation of Waste Minimization

All waste minimization steps should be clearly documented, maintained on file, and available for review upon request. Waste minimization is required by state and federal laws. As such, it is the University’s responsibility to prove that adequate steps have been taken to minimize the creation of hazardous waste.

Many treatment procedures such as neutralization must be documented and the files must be maintained and readily available. It is the area’s responsibility to maintain records. A copy of all records must be sent to EHSS on a quarterly basis.

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