# Sink Disposal ## Summary How to pour chemical, hazardous, radioactive, and other waste into sinks and drains. ## Who is this for? - Building and operations management. - Labs and research. ## Sink and drain disposal at Harvard Buildings and labs in Allston, Cambridge, Somerville, and the Longwood Medical Campus must follow Massachusetts Water Resources Authority (MWRA) or local sink and drain disposal limits and restrictions. Buildings and labs in non-MWRA areas like Concord and Petersham have similar drain disposal requirements and may have additional disposal limits. Harvard must report all chemical discharge violations with potential enforcement action to the MWRA. MWRA enforcement actions are cumulative and can lead to fines, penalties, and increased monitoring. Repeated violations can jeopardize research and operations. ## Sink disposal by material Follow sink disposal requirements for each type of waste. Always confirm that your waste is approved for drain disposal before pouring it down a sink drain. The MWRA prohibits disposing of any amount or concentration of some materials and substances down a sink or drain. You cannot dilute these substances for sink disposal. Open all sections Close all sections ### Chemical waste expand\_more Search for [sink disposal requirements by chemical](/resource/chemical-waste-hazard-and-sink-disposal-tool "Chemical Waste Hazard and Sink Disposal Tool"). ### Corrosive solutions expand\_more Corrosive solutions have a pH of either: - 5.5 or less. - 12.0 or greater. You must receive approval from the building manager before you dispose of any corrosive solutions down a sink or drain. In some lab buildings with neutralization systems for mildly corrosive wastewater, you may be permitted to dispose of weak corrosive solutions down the sink. At the end of your lab process, manage any corrosive solutions with a pH less than 2.0 or greater than 12.5 pH as [hazardous waste](/resource/chemical-and-hazardous-waste "Chemical and Hazardous Waste"). ### Disposal restricted waste expand\_more Ensure [disposal restricted waste (DRW)](/resource/disposal-restricted-waste "Disposal Restricted Waste") is analyzed and evaluated before drain disposal. Examples of DRW include glycol, vegetable oil, and wastewater that must be analyzed. ### Flammable and explosive waste expand\_more Improper drain disposal is dangerous for lab and facilities staff, especially during low-flow periods such as after normal working hours. Never dispose of waste materials with these characteristics down a sink or drain: - Explosive at the time of disposal. - Flammable (flash point less than 140°F). Examples include acetone, alcohols, aldehydes, ethers, gasoline, ketones, methyl ethyl ketone, peroxides, toluene, and xylene. ### Hazardous waste expand\_more Never dispose of hazardous waste down a sink or drain. You must [disinfect biohazardous waste](/resource/biosafety-manual "Biosafety Manual") before sink disposal. Hazardous waste either: - Contains an Environmental Protection Agency-listed or Department of Environmental Protection-listed hazardous waste substance. - Exhibits any of these characteristics: - **Ignitability:** Flash point less than 140°F. - **Corrosivity:** pH less than 2 or greater than 12.5. - **Reactivity:** Contains cyanides or sulfides or may emit toxic vapor when mixed with water. - **Toxicity:** Contains substances at concentrations greater than the amounts specified in the regulations. This includes P or U EPA-listed materials. Classify aqueous solutions with more than 50% water and less than 24% alcohol by volume as non-hazardous waste. #### Hazard statements If Section 2.2 of the safety data sheet (SDS) lists any of the following hazard statements, collect the chemical substance as waste. These materials are generally prohibited from drain disposal: - H300 Fatal if swallowed. - H310 Fatal in contact with skin. - H330 Fatal if inhaled. - H340 May cause genetic defects. - H341 Suspected of causing genetic defects. - H350 May cause cancer. - H351 Suspected of causing cancer. - H360 May damage fertility or fetuses. - H361 Suspected of damaging fertility or fetuses. - H400 Very toxic to aquatic life. - H401 Toxic to aquatic life. - H402 Harmful to aquatic life. - H410 Very toxic to aquatic life with long lasting effects. - H411 Toxic to aquatic life with long lasting effects. - H412 Harmful to aquatic life with long lasting effects. - H413 May cause long-lasting harmful effects to aquatic life. ### Radioactive waste expand\_more Do not use sink disposal as the primary way you dispose of radioactive waste or radionuclides. Only use a sink to dispose of materials that meet these criteria: - Trace amounts and washings containing radioactive materials in quantities less than the radionuclide daily sink disposal limit listed on the radionuclide sink disposal log. - Non-hazardous materials that are readily soluble or dispersible in water. For other materials, follow [radiation waste disposal procedures](/resource/radiation-waste "Radiation Waste"). #### Disposing of radioactive materials To dispose of radioactive materials down a sink drain: 1. Use an approved sink labeled with a “Caution Radioactive Material” sticker. 2. Record the date of disposal, a reasonable estimate of the maximum activity discharged, and your initials on the radionuclide sink disposal log posted near the sink. 3. After disposal, flush the sink with water for at least 10 minutes and survey the sink to confirm that there are no residual radioactive materials. #### Determining solubility in water For liquid waste, first identify the chemical form of all the waste materials. Then you can use one of these methods to determine a chemical compound's solubility in water: ##### Solubility class You can use most chemistry or physics handbooks to determine solubility class. - **Decomposed (d) species of compound is s or vs or d species is simple ions:** Readily soluble. - **Insoluble (i), slightly soluble (sls), or very slightly soluble (vsls):** Not readily soluble. - **Soluble (s) or very soluble (vs):** Readily soluble. ##### Formal solubility Use the equations in the [Radiation Safety Manual](/resource/radiation-safety-manual "Radiation Safety Manual") to determine formal solubility. - **Formal solubility less than or equal to 0.003 mol/L:** Not readily soluble. - **Formal solubility greater than 0.003 mol/L:** Readily soluble. ### Rinsate expand\_more In most cases, follow this process to dispose of rinsate: 1. Collect the first rinse (with either or both water and acetone) from containers that held any materials prohibited or limited for sink disposal as [hazardous waste](/resource/chemical-and-hazardous-waste "Chemical and Hazardous Waste"). 2. Dispose of subsequent rinses, which contain very low concentrations, down a sink or drain unless the container held a [P-listed chemical](https://www.epa.gov/hw/defining-hazardous-waste-listed-characteristic-and-mixed-radiological-wastes). If the container held a P-listed chemical, you must: 1. Triple-rinse the container. 2. Collect the rinsate from each rinse as hazardous waste. ## Other prohibited waste Do not pour materials with any of these characteristics into a sink or drain: - Fat, grease, or oil at concentrations above 300 mg/L. - Infectious or biological waste. - Liquid or vapor hotter than 180°F. - Liquids, gases, or solids with a strong or unpleasant odor that could create a nuisance, such as chemicals or dyes like mercaptans or thiols. - Mercury or mercury salts or dyes. - Mixtures with controlled substances. - Nanoparticles or materials that could bioaccumulate. - PCBs. - Pesticides. - Petroleum hydrocarbons at concentrations above 15 mg/L. - Sludge or slug (excessive amount of viscous material). - Solid or viscous substances that could clog or block drains. Examples include tissues, glass, pipette tips, plaster, plastics, rubber, sand, wood chips, or wood shavings. - Solutions that exceed [MWRA discharge limits](/node/946#sink-disposal-regulated-waste-discharge-limits). ## Regulated waste and discharge limits You can only discharge extremely low concentrations of certain regulated substances down the drain. Because lab buildings use large quantities of chemicals and the MWRA’s discharge limits are very low, only dispose of de minimis (extremely low) concentrations of regulated substances down a sink drain. The MWRA monitors Harvard’s wastewater and calculates permit fees based on the total amount of discharged substances. These fees can add up to thousands of dollars. Reduce or avoid discharging regulated substances from your building to help control permit fees. Open all sections Close all sections ### Daily maximum limits expand\_more Sort Daily maximum limits of MWRA regulated substances in mg/L. Regulated Substance MWRA Daily Maximum Limit (mg/L) 1,1-Dichloroethylene 0.3 Acrolein 0.15 Antimony 10 Arsenic 0.5 Benzene 0.3 Cadmium 0.1 Chromium (+6) 0.5 Chromium total 1 Copper 1 Cyanide 0.5 Formaldehyde 9 Hexachlorobutadiene Prohibited Lead 0.2 Mercury Prohibited Nickel 1 PCBs Prohibited Pesticides Prohibited Phenol 5 Selenium 5 Silver 2 Toxic organics 1 Toxic organics total (as a combined total) 5 Vinyl chloride (chloroethylene) 0.02 Zinc 1 ## Related resources Find documents and online tools to manage sink disposal. [### Chemical Sink Disposal Poster ](/resource/chemical-sink-disposal-poster)Printable poster to check if you can pour chemical waste into a sink drain [### Chemical Waste Hazard and Sink Disposal Tool ](/resource/chemical-waste-hazard-and-sink-disposal-tool)Common chemical waste hazard designations and sink disposal requirements [### Radionuclide Sink Disposal Log Form ](/resource/radionuclide-sink-disposal-log-form)Form to document pouring waste with radionuclides into a sink drain [### Sink Disposal and Wastewater Discharge Poster ](/resource/sink-disposal-and-wastewater-discharge-poster)Printable poster about wastewater discharge and sink disposal requirements ## EHS support Contact EHS for more information about sink disposal: - **General sink disposal and determining disposal requirements:** [Contact EHS](/contact-us "Contact Us"). - **Lab buildings:** Contact [lab\_safety@harvard.edu](mailto:lab_safety@harvard.edu) or your [Lab Safety Advisor (LSA)](/resource/ehs-safety-officers "EHS Safety Officers"). - **Radioactive waste and radionuclides:** Contact [radiation\_safety@harvard.edu](mailto:radiation_safety@harvard.edu). See also:- [ Building and Operations Managers ](/audience/building-and-operations-managers) - [ Labs and Research ](/audience/labs-and-research) - [ Controlled Substances ](/topic-areas/controlled-substances) - [ Waste Management and Disposal ](/topic-areas/waste-management-and-disposal) - [ Chemical and Hazardous Waste ](/topic-areas/chemical-and-hazardous-waste) - [ Sink Disposal ](/topic-areas/sink-disposal) - [ Radiation Waste ](/topic-areas/radiation-waste)