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Chemical Waste Disposal

Prior to generating chemical waste, you must classify it by determining its hazardous properties. By doing this first, you will be able to choose a compatible container to collect the waste, know how to label the container and stay within the accumulation time limits. 

Flammable/Ignitable. (1) Liquids (with less than 50% water by weight) with a flashpoint of less than 60 °C (e.g., gasoline, benzene, alcohols, acetone, and ethers); (2) solids that can cause fire through friction, absorption of moisture, or spontaneous chemical changes, and when ignited burn so vigorously and persistently that it creates a hazard; and (3) ignitable  compressed gases.

Corrosive. (1) Liquids with a pH of less of ≤ 2 (e.g., sulphuric acid); (2) liquids with a pH ≥ 12.5 (e.g. potassium hydroxide); (3) solids, that when mixed with an equivalent weight of water, produce a solution having a pH ≤ 2 or ≥ 12.5 (e.g., hydrated lime, acetamide, cupric bromide).

Reactive. (1) Liquids or solids that are normally unstable and readily undergo change without detonation, react violently with water, or generate toxic gases or fumes when mixed with water; (2) chemicals containing cyanide or sulphur and which generate toxic gases when exposed to pH conditions between 2 and 12.5; (3) chemicals which are capable of detonation if subjected to a strong initiating source, or heated under confinement; or (4) chemicals capable of detonation at standard temperature and pressure. Examples: pyrophoric liquids, sodium cyanide, potassium sulphide, potassium metal, dry picric acid.

Toxic. This is the default hazard waste characteristic for chemical waste that is not flammable, corrosive or reactive. Unless you have documentation, such as a toxicity assessment or bioassay testing, which clearly shows that the waste is non-toxic, label your waste as toxic. LS/LSS can assist you with sampling and waste analyses.

Oxidizer. Oxidizer is a secondary hazardous property. Indicate on the waste label the primary hazard of the oxidizer in addition to "Oxidizer" (e.g., Piranha waste is a corrosive acid and an oxidizer). Oxidizers cause or enhance the combustion of other materials and are a fire hazard if stored or transported incorrectly.

For more information, please see Chemical Safety section.

Waste Management Program

Sabancı University FENS has chemical waste management regulations and here are the general guidelines for chemical waste disposal:

  • Eliminate the need for disposal of unused chemicals by not purchasing more than the quantity of chemicals needed for your experiments.
  • Try to use non-hazardous chemicals in place of hazardous chemicalswhenever possible.
  • Do not dispose of flammables, organic solvents, toxic materials, corrosive materials, reactive materials, odorous chemicals, or water insoluble materials down the drains.
  • Dispose of Ethidium Bromide as a chemical hazardous waste (Please see section A.3.5 Disposal of Ethidium Bromide Waste).
  • Place all hazardous waste containers in a secondary containment.
  • Separate incompatible chemical waste.
  • The containers must be kept properly and securely closed.
  • Attach the Hazardous Waste tag to each waste container. Complete all information requested.
  • When waste container is ready for pickup, put the container in the defined waste area of the laboratory, create an “inquiry” from call center 9988 and inform LSS.

Chemical Waste Containers

All waste containers must be labelled with the words “hazardous waste” the chemical composition of the waste, its hazards, and the accumulation start date (the date the waste is first produced).

University Services requires a “Hazardous Waste ID Tag” be completed and placed on the container when it is first designated as a waste. See FigureA.3 for an example tag.

Accumulation time limits: SU policy states that waste can only be stored in a lab for 90 days. Full containers are required to be removed from labs within 2 weeks.

 an example tag.

Container and packaging requirements:

  • The waste must be accumulated in containers that are in good condition and it should be compatible with the container it is stored in.
  • The container must be kept closed except when the waste is being added to or removed from the container.
  • Liquids must be collected in containers with screw tops or sealed lids.
  • Do not completely fill the container. Leave the container less than 75% full.
  • Dry waste must be double bagged in clear plastic bags.
  • Paper towels are not hazardous waste unless hazardous chemicals are spilled on the towel.
  • Liquids are required to be separated from solids.
  • Mercury must be collected in a screw cap bottle. Double bag mercury contaminated items and broken thermometers in clear plastic bags (Use mercury spill kit and be aware of the danger). Please see Emergency Procedures section.

Figure A.3 Waste bottle label example

Waste storage amount limits: The maximum amount of waste allowed to be stored in a laboratory is:

  • 1 liter acute / extremely hazardous waste
  • The maximum amount of solvent allowed to be stored in a lab is 50 liters including waste solvents. 

Chemical Waste Pick-up Procedure

Chemical waste is picked up on a regular schedule by Housekeeping Unit staff upon an ‘inquiry from call center (9988)’. Each laboratory must package, tag, and hand their waste at the scheduled time.

Separate incompatible chemicals during transport and storage. Store and transport chemicals by hazard classes:

  • Flammable Solid
  • Flammable or Combustible Liquid/Solvent
  • Nonhalogenated, halogenated
  • Corrosives
  • Acids – also separate organic, inorganic, nitric
  • Bases
  • Oxidizers
  • Poisons or Toxic
  • Carcinogens, mutagens, irritants, formaldehyde
  • Explosives/Shock Sensitive
  • Water reactives
  • Organic peroxides
  • Heavy Metals

These items will not be accepted at chemical waste pick-ups:

  • Leaky containers
  • Containers with exterior chemical contamination
  • Containers which are too full. Do not fill containers over 90%.
  • Radioactive waste
  • Bags containing protruding glass and other sharps such as needles, blades or glass pipettes
  • Bench diapers unless hazardous chemicals were spilled on the diaper

Dangerous Chemical Waste, Unknowns

Acutely dangerous waste:

Do not move acutely dangerous or unknown wastes which are shock sensitive or whose containers are leaking due to corrosion or which have no labels.

Peroxide forming chemicals (PFCs):

Once a peroxide forming chemical has been opened, the lab has one year to use it. After one year, it has to be disposed of as hazardous waste.  PFCs normally will not start forming explosive peroxides if they are not expired.

Empty Cylinders

If a compressed gas tank is empty please follow the regulations below and inform LS.

  • Remove the regulator and replace the cylinder cap.
  • Mark the cylinder as empty or MT and store in a designated area for return to the supplier.
  • Do not store full and empty cylinders together.
  • Do not have full and empty cylinders connected to the same manifold. Reverse flow can occur when an empty cylinder is attached to a pressurized system.
  • Do not refill empty cylinders. Only the cylinder supplier should refill gases.
  • Do not empty cylinders to a pressure below 25 psi (172 Kpa). The residual contents may become contaminated with air.

References and sources for information from the relevant websites and documentation of different universities, NGOs and government agencies used in the preparation of this website are provided at references.