Chemical Waste Minimization/Source Reduction

Introduction

Federal and state regulations governing hazardous waste requires that generators of hazardous waste develop and implement waste minimization procedures. The guidelines listed below are some good examples on how to minimize waste generated in the laboratory. Waste minimization is not only good for the environment but also reduces University costs associated with chemical waste disposal.

All chemical waste must be disposed of through the Department of Environmental Health & Safety. Chemical waste includes but is not limited to:

  • Unwanted laboratory reagent chemicals
  • Chemical mixtures generated through laboratory research and education processes
  • Glassware and debris contaminated with chemical residues
  • Contaminated debris generated during chemical spill clean-ups
  • Paints, oils, pesticides, cleaners, etc.

Guidelines for Reducing Chemical Waste

  • Before disposing of a reagent grade chemical, determine if someone else has a need for the chemical.
  • Establish chemical use parameters before placing order. This will minimize waste by purchasing chemicals in the container size that permits maximum consumption.
  • Purchase chemicals in small quantities. The contents of small containers are more likely to be utilized than lost to contamination or degradation. Also, if disposal is required, volume and expense will be minimized if waste is in small containers.
  • Whenever possible, substitute less-hazardous chemicals for hazardous ones. Examples: Substitute "no-Chromix" for chromerge; cyclohexane for benzene; non-mercury thermometers for mercury containing thermometers.
  • Avoid stock piling of common chemicals. Stock piling involves the purchasing or accumulation of chemicals in large quantities for use longer than needed. This practice usually jeopardizes the chemicals' properties over a period of time. Also, many chemical suppliers offer "just in time" orders which still allow the purchaser to take advantage of bulk pricing.
  • When chemicals are received take all precautions to store them according to manufacturers' recommendations such as by refrigeration, under an inert atmosphere or in a dessicator. Following special storage requirements can increase the shelf life of chemicals.
  • When chemicals are received, date and store them in a manner that enables the older chemicals to be used first. This will develop a rotational system so that chemicals will be used before shelf life expires.
  • Replace worn labels in a permanent, legible fashion. This will prevent an unknown chemical from being generated. Unknown chemicals are difficult and expensive to manage as a waste.
  • Label all containers and reaction flasks that contain or will contain chemicals. DO NOT use abbreviations, trade names or chemical symbols. Only use the common chemical name or IUPAC nomenclature to identify each container's contents. This will prevent an unknown chemical from being generated.
  • Replace faulty or damaged caps and lids. This will safeguard against the effects of air and moisture contamination.
  • Inventory the chemicals in your laboratory every six months. During the inspection replace worn and damaged labels. Assure that chemicals are stored by compatibility and not alphabetically. Get rid of unwanted chemicals that will no longer be needed. This practice will prevent the disposal of large volumes of chemicals when a laboratory is vacated and reduce the potential of a chemical becoming an unknown due to a deteriorating label. Also get rid of chemicals that tend to form peroxides or become more reactive with time that are approaching the end of their shelf life. For example, ethyl ether and tetrahydrofuran tend to form explosive peroxides and picric acid becomes shock sensitive when dry.
  • If repeated dispensing of liquids is required, utilize a calibrated pipette or bottle top dispenser. Decanting liquids in calibrated beakers or graduated cylinders tends to generate large quantities of waste. Potential hazards such as spillage and personal exposure are also reduced by using bottle top dispensers and pipettes.
  • Reduce the scale of the experiment if protocol permits. Less chemicals used equates to less waste.
  • Gas cylinders should be inspected on a regular basis. Ensure that the label is in good condition. Unknown gas cylinders present a serious hazard and are very expensive to manage as a waste. Utilize a gas vendor that will accept the cylinders back when they are no longer needed. Never refill a gas cylinder. Refilling of cylinders must only be completed by the gas cylinder vendor. Follow all safety procedures when utilizing compressed gases and liquids.

Special Notes

  • Reagent grade chemicals are very expensive to dispose of compared to routine chemical wastes generated by research and education.
  • Approximately 25% of laboratory chemical waste disposed of on an annual basis through the Department of Environmental Health & Safety are reagent grade chemicals
  • A lecture size gas cylinder will typically cost between $150 to $1,000 to dispose of depending on the cylinder's contents, age and condition. Unknown cylinders and highly reactive gases are much more expensive to handle.
  • Very poisonous and reactive compounds such as sodium cyanide and concentrated organic peroxides have to be managed as individual containers which significantly increases disposal costs.

Questions regarding the chemical waste minimization procedures or on the chemical waste disposal program should be addressed to Jane Frank or call 831-2103.