Segregate chemical, biological and sharps waste, and follow the decide-alert-contain steps of a spill procedure.
Awareness level only. This lesson explains the ideas so you recognise them. It does not qualify you to do this work. Before you handle chemicals, biological materials or lab equipment for real, you need the training your employer or institution requires, and you must work under supervision until they sign you off.
Why it matters
Lab waste can injure the cleaner who empties a bin, start a fire in a drum, or pollute water if it goes down the drain. Spills turn a controlled procedure into an uncontrolled hazard in seconds. Laws such as the US Resource Conservation and Recovery Act (RCRA), administered by the EPA, regulate hazardous waste, and OSHA rules cover sharps and bloodborne pathogens. Every institution turns these into local procedures, and your job is to know and follow them.
Waste streams: segregate at the source
The key habit is putting each item in the right container the moment you are done with it. Mixing streams can cause reactions, and it makes disposal dangerous and expensive.
| Stream | Container | Examples |
|---|---|---|
| Hazardous chemical waste | compatible, closed, labelled container (often provided by EHS) in a designated accumulation area | used solvents, acid solutions, heavy-metal solutions |
| Biohazardous waste | red or orange biohazard bag in a rigid, lidded container; usually autoclaved or treated | cultures, contaminated gloves and plastics from BSL-2 work |
| Sharps | rigid, puncture-resistant, labelled sharps container | needles, scalpel blades, contaminated glass slides, pipette tips (per local rule) |
| Broken glass (uncontaminated) | cardboard broken-glass box | clean broken beakers |
| Regular trash | normal bin | uncontaminated paper and packaging |
Some specialised streams also exist: radioactive waste (handled by a radiation safety officer), and universal waste such as batteries and lamps.
Chemical waste rules of thumb
- Label as soon as the first drop goes in: "Hazardous Waste", full chemical names (no formulas or abbreviations), and approximate percentages, following your institution's label.
- Keep containers closed except when adding waste. A funnel left in the bottle counts as open.
- Never mix incompatibles, for example oxidising acids with organic solvents, or acids with cyanides. Check SDS section 10.
- Use secondary containment (a tray) under liquid waste.
- Nothing goes down the drain unless your institution explicitly approves that specific material.
- Request pick-up before the container is full or the time limit is reached.
Sharps rules
- Never recap needles by hand; drop them straight into the sharps container.
- Do not overfill: close and replace the container at the fill line (often about three-quarters full).
- Never reach into a sharps container or push waste down.
- Pick up broken glass with tongs, forceps or a brush and dustpan, never fingers.
Spills: decide, alert, contain
Before any spill happens, know where the spill kit, eyewash, safety shower, fire extinguisher, exits and emergency number are.
When a spill happens:
- Stop and assess. What is it, how much, where, and is anyone hurt or contaminated?
- Take care of people first. For chemical contact with eyes or skin, use the eyewash or safety shower right away, typically for at least 15 minutes, remove contaminated clothing, and get medical help.
- Alert people nearby and your supervisor.
- Decide: minor or major.
- Minor: a small amount of a known, low-hazard material you are trained and equipped to clean up.
- Major: large volume, highly toxic, flammable near ignition sources, unknown material, anyone injured, or you are unsure. Leave the area, close the door, and call your emergency number or EHS. Do not try to be a hero.
- For a minor spill: put on the right PPE, contain the edges with absorbent from the spill kit, work from the outside in, use neutralisers only if your procedure says so, collect the material, and bag and label it as hazardous waste.
- Report it, even if it was small (see module 3).
Biological spills
For a spill of biological material, your lab's procedure typically has you alert others, leave the area for a set time if aerosols may have formed, then cover the spill with absorbent material, apply an approved disinfectant from the outside in, leave it for the required contact time, and dispose of everything as biohazardous waste. Spills inside a biosafety cabinet are cleaned with the cabinet left running.
Worked example
You knock over a 100 mL beaker of dilute sodium chloride solution at the bench. It is a known, low-hazard material: minor. Tell your neighbour, put on gloves, soak it up with paper towels, wipe the area and dispose of the towels as your lab directs. Now change one fact: the beaker held 100 mL of concentrated nitric acid. It is corrosive and an oxidiser and gives off vapour. Unless you are specifically trained and equipped, treat it as major: alert, leave, close the door, call for help.
Common mistakes
- Mixing waste streams "because the bottle had room".
- Abbreviations on waste labels (EtOH, DCM) that responders cannot read.
- Overfilling sharps containers.
- Cleaning a spill you do not understand.
- Not reporting a "small" spill.
Quick recap
- Segregate waste at the source: chemical, biohazard, sharps, glass, trash.
- Label chemical waste fully, keep it closed and away from incompatibles; nothing down the drain without approval.
- Spills: people first, alert, decide minor or major, contain or evacuate, report.
Official source: US EPA, Hazardous Waste, https://www.epa.gov/hw (Checked on 2026-10-23.)
Try it
Open the Do tab and build your own spill and waste quick-reference card on paper.