Transcript Wastes
Bio Sciences: Chemicals Lab Waste Bellwork How does a serial dilution differ from a specific dilution? Objectives 1. 2. 3. Give reasons for needing to dispose of chemicals safely List four categories of chemicals for disposal Write a flow chart for lab waste disposal Terminology Halogenated-Solvents: These are organic solvents with halogens (Cl, F, Br, I, etc.). Are We Finished? So you have just completed an experiments, you have all your data and it is time to clean up. Before you can wash out all of your equipment you need to dispose of your left over chemicals/ biologicals. http://www.duanestorey.com/2010/down-the-drain/ Can they just go down the drain? Come up with at least two (2) reasons they can or can not with your partner. http://bostinnovation.com/2011/03/02/mit-gets-2m-injection-for-innovative-educational-outreach/ What to Do With It? The Drain or a proper container? It depends – Your teacher will instruct you what to do every experiment –but if you do not know ALWAYS ASK What are some environmental implications of improper chemical/ biological disposal? We need at least six (6) Fines: EPA will levy fines on the school if waste disposal turns into pollution because of improper disposal Chemical Waste Categories May vary from lab to lab. This is a VERY brief categorization based on what is used in most high school labs. University and industry lab have many more categories and sub-categories. Aqueous (liquid) Wastes: Corrosives Organics Toxics Biologicals Solids Wastes: Chemicals Filter Media Biological Sharps/ Specimen containers Corrosives Acids and Bases – Should be neutralized before being put in proper container (Organics and Inorganics). Generally your teacher will do this for you once it is all collected after an experiment. A/B partner Quiz: What acid should never be stored with other acids? Should we dispose of it with other acids? Solids: Need to be put in a separate corrosive solids bin and placed with compatible chemicals only. Ex. Solid KOH or NaOH Organics Solvents: Most of the solvents other than water we will use are organics (like isopropyl alcohol or methanol). These are non-Halogenated solvents and can be disposed of in a Non-halogenated container. Never pour Alcohols/ organic solvent/ acetone/ ethidium bromide down drain! Halogenated-Solvents: These are organic solvents with halogens (Cl, F, Br, I, etc.) like TCM, TCE, DMSO, etc. Should be disposed of in a dedicated container Toxics Heavy metals: Individual metals or metal compounds that may adversely affect peoples health, ex. Hg, Pb, etc. These can be in aqueous solutions or in solid form. If heavy metals are present disposal methods are more expensive and take more care. Toxics cont. Predict: Where else are heavy metals a disposal issue – hint think of your home? How could they be an issue? Biologicals Regulated Medical Waste. Live or Died – the biggest concern is for biohazards. These wastes may include the following: Sharps, e.g. glass implements, needles, syringes, blades, etc. used with infectious materials Biologically-cultured stocks and plates, human blood or tissues Biologicals cont. Sterilize or disinfect waste materials associated with viral, bacterial or other agents infectious to humans. Place all biohazardous wastes, except for sharps, directly into red bag-lined medical waste boxes. Place sharps into labeled sharps containers which when filled are placed into the medical waste box. Waste Labeling Just like when we make a solution, when we dispose of one we need to label the container it is in with info for disposal. What should this label contain? Date filled Contents (%, or quantity of parts) Specific hazards (toxic, corrosive flammable, etc. Examples Waste Storage Container choice: Plastic vs. Glass vs. Metal Need to insure there is not a reactivity issue – example HF acid never goes in a glass container because it will dissolve the glass. Time: How long to keep waste before professional removal? Varies, but the sooner it can be taken off site the better – schools generally have wastes removed once a year or when wastes storing capacity is full. Waste Storage Cont. Compatibility Acids and bases Organics and acids Cyanide, sulfide or arsenic compounds and acids Alkali or alkali earth metals, alkyllithiums etc. and aqueous waste Powdered or reactive metals and combustible materials. Mercury or silver and ammonium containing compounds Waste Prevention The most effective way to deal with waste is prevent it, but when you must have waste do the following: Prepare only what is needed; minimize waste FIFO of chemicals Label everything so it does not automatically get classified as hazardous waste and have to be analyzed Substitute hazardous and toxic materials for nonhazardous/toxic when possible Lab Waste Flow Chart Using the graphic organizer on the last page of your note-taker, try to devise your own waste disposal flow chart, based on what we have discussed in class today. You will have the remainder of class up to the last 3min. What you do not finish is homework. Closure Write brief a letter or a note to a friend explaining how to deal with lab waste on a separate sheet of paper.