Proper Disposal of School Chemicals
Several options are available for schools when deciding how to dispose of unneeded or unusable chemical wastes. These disposal methods are dependent on the type of chemical and its hazardous characteristics.
For no-longer-useful pure chemical compounds in the science laboratories, Fill out the chemical pick up form and place the chemical’s name for in-depth information on its hazards and proper disposal method. Once completed send information and where the chemical will be stored for pick-up.
Environmental Health and Safety (EHS) will pick up chemicals on an as needed basis, per request of the school. It is highly recommended that the forms be filled out at least 2 weeks prior to pick up. If you have any questions or concerns please contact EHS 972-925-4500.
These are the three most commonly generated waste mixtures from school science labs - heavy metals solutions, corrosive liquid wastes, and organic solvent wastes. Please see basic information below on how to properly handle these materials.
- Heavy Metals Solutions: Collect waste liquids containing heavy metals in a single large wide-mouthed container lined with a sliding lock plastic bag. Leave the bag open so most of the water can be evaporated in a fume hood. When the bag is full of settled solids, zip it closed and place it in a five-gallon bucket labeled “Hazardous Waste – Heavy Metals” and snap the lid closed. When this five-gallon bucket is full of bags of sludge, dispose of it as hazardous waste. Keep a log sheet listing the name and amount of the waste solutions that are placed in the bags and the date they were added. An inventory of what the waste is made of can save you the expense of testing for identification by the hazardous waste disposal vendor or site when it is disposed.
- Organic Solvents: Collect waste solvents in a glass or metal container with a tight-sealing lid. Label this container with the words Hazardous Waste. Keep a log of the amount and type of organic compounds added to the container on a log sheet with the date they were added. If you have chlorinated solvent waste, store it in a separate container labeled “Chlorinated Solvents” to reduce costs Waste solutions containing over 24 percent alcohol are ignitable hazardous waste and cannot be disposed down the drain nor evaporated in the fume hood.
- Corrosive Liquids: Concentrated acids and bases must be disposed as hazardous waste. Dilute inorganic acid and base solutions (1.0 molar or less) can be neutralized to a pH between 6.0 and 11.0 and discharged to the sanitary sewer, provided they’ve not been contaminated with heavy metals. Keep a log sheet that tracks the amount of acidic or basic waste generated and the date it was neutralized on a log sheet. When the pH is correct, the solution can be drained to the sanitary sewer with a water rinse of 50 times the acid or base’s volume.
Email RDENNIE@dallasisd.org for chemical disposal form and for all general questions. If Chemical Disposal Services are not requested by September 15th, services will not be rendered until the following year.