Policy on Drain Disposal of Chemicals

Federal, state and local governments have established strict rules and regulations for chemical disposal.  These rules and regulations have been established primarily to protect human health and the environment.  Accordingly, Columbia University has developed and maintains policies and procedures for the proper handling of chemicals, which limits the use of sink or floor drains for disposal.  Environmental Health & Safety (EH&S) administers the Hazardous Waste Management program to ensure that chemical waste is safely and legally disposed of at an EPA permitted waste disposal facility. 
All persons employed by or working on behalf of the University who handle or use chemicals must strictly adhere to this Policy.

All persons employed by or working on behalf of the University who handle chemicals must familiarize themselves with the Hazardous Waste Management program, including the “5Ls of Hazardous Waste Management”, which are the 5 principles of chemical waste collection. 

In accordance with the University’s commitment to protecting human health and the environment and strict adherence to hazardous waste regulations, all hazardous chemical waste must be collected and properly disposed.  Since the definition of hazardous waste is broad and the overwhelming majority of laboratory chemicals used at the University fall within this definition and thus require collection as hazardous waste, there are few chemicals that are permitted to be drain disposed.  Additionally, New York City Department of Environmental Protection (DEP), the agency which regulates the City’s sewage treatment plants and thus the drains that feed the City’s wastewater system, categorically forbids flammable liquids and toxic substances, as well as corrosive chemicals, from entering the public sewers.  Local municipalities such as Rockland and Westchester Counties have similar prohibitions on substances entering the sewers.

The following non-hazardous substances are permitted to be drained disposed assuming that they are not mixed or contaminated with hazardous chemicals (such as heavy metals, solvents, corrosives, toxics) or radioactive materials.  EH&S reserves the right to approve the discharge and/or drain disposal of all substances on a case-by-case basis.

Non-Hazardous Substances Permitted for Drain Disposal

  1. Physiological saline and non-toxic salts in dilute form
  2. Inorganic buffers (phosphate or bicarbonate based)
  3. Buffer solutions containing ethidium bromide that have been filtered, decontaminated, or destroyed using a method acceptable to EH&S (see Ethidium Bromide: Safe Handling and Proper Disposal Policy for accepted methods)
  4. Organic buffers at use concentrations (e.g., TRIS)
  5. Sugar solutions
  6. Liquid tissue culture media, fresh or spent supernatant, which has been rendered non-infectious

Examples of Hazardous Substances Prohibited from Drain Disposal

  1. Ethanol: an ignitable/flammable chemical that meets the ignitability characteristic of hazardous waste as defined by EPA/NYSDEC, thus must be collected for hazardous waste disposal.  As a flammable liquid, it is also forbidden from entering the public sewer (even with copious amount of water).
  2. Acetone: see Ethanol
  3. Methanol, Propanol and Butanol: see Ethanol
  4. Chromerge: a sulfuric acid (e.g., corrosive) and chromium trioxide (e.g., toxic) solution use for cleaning laboratory glassware.   This mixture is a corrosive, toxic hazardous waste.  EH&S always recommends laboratories try alternative glass cleaning products (such as Alconox or NoChromix). 
  5. Dyes and Stains: the exact chemical contents of dyes and stains will determine whether they may be drain disposed.  For example, Coomassie Blue and “Destain”, which contain methanol and acetic acid, would both be considered hazardous wastes and prohibited from drain disposal.  EH&S recommends all dyes and stains be collected for proper waste disposal.
  6. Ethidium Bromide Solution: due to its mutagenic properties it must be collected for hazardous waste disposal, unless filtered, decontaminated or destroyed, using methods approved by EH&S (see Ethidium Bromide: Safe Handling and Proper Disposal Policy for accepted methods)  

There are two important issues related to drain disposal and hazardous waste collection that must also be mentioned.  The EPA, NYSDEC and DEP generally DO NOT base decisions on quantities or volume limits, which means even small quantities of chemical waste must be collected for proper disposal.  Also, the evaporation, intentional dilution or neutralization of a hazardous chemical waste for the purpose of avoiding collection of that chemical as a hazardous waste is illegal. 

Feel free to contact EH&S if you have any questions about the University’s “No Drain Disposal” policy.