1.6 Hazardous Waste Minimization

In an average year, The University of Iowa generates 25,000 – 30,000 containers holding approximately 250,000 lbs. of hazardous chemical waste. It is the goal of the University to reduce this amount. Waste minimization is a reduction in both toxicity and volume, thus contributing to increased safety of personnel and benefiting our environment. Waste reduction practices also help control increasing expenditures of hazardous waste disposal. Common techniques include:

Product Substitution

Use less hazardous or non-hazardous materials.

  1. Substitute No-Chromix, Alconox, Terg-a-Zyme or other non-toxic detergents and enzymatic cleaners for chromic acid or potassium hydroxide/ethanol cleaning solutions.
  2. Substitute non-hazardous biodegradable liquid scintillation cocktails for xylene and toluene-based cocktails.
  3. Use soy-based inks instead of solvent-based inks in printing.
  4. Use dry instead of wet printing processes.
  5. Use non-halogenated solvents in degreasing operations.
  6. Use non-mercury and non-sodium azide preservatives.
  7. Use spirit, bi-metal, or digital thermometers.
  8. Substitute ethanol for formaldehyde in specimen preservation.
  9. Use water-based paints instead of oil-based paints.

Scale Down

Use microscale techniques to reduce or eliminate waste.

Waste Segregation

  • Keep wastes segregated. Certain waste mixtures are more expensive to dispose of than others. For example, disposal of a gallon of xylene contaminated by mercury can cost one hundred times that of xylene alone.
  • Keep non-hazardous waste out of hazardous waste streams. This includes water in solvents, or paper and plastic in dry waste.

Waste Recovery

  • Re-distilling solvents is a way to save the cost of purchasing new solvents. There are many lab-scale stills on the market.

Chemical Neutralization

  • Neutralize dilute acids and bases in the lab.
  • Deactivate carcinogens.

Good Management

  • Maintain an inventory of chemicals in the area and discard any no longer in use. This will also prevent duplicate purchases.
  • Label all materials. Unknown materials are expensive to analyze.
  • Use waste generation as a criterion in the selection of new equipment.
  • Purchase small quantities - The cost of disposing of excess can easily outweigh initial savings.
  • Redistribution - Consult your colleagues; someone else may be able to use surplus.
  • Train employees in waste management practices.