Lab waste is waste that is generated from laboratories in a variety of industries and in educational centres such as schools and universities.

This waste can be broken down into different categories: -

Hazardous; - Clinical; - Biological; - Electrical; - Laboratory.

A significant proportion of solid waste from a laboratory is likely to consist of non-hazardous waste. Items such as paper, tissues, disposable gloves, packaging, rinsed plastic-ware, rinsed glass-ware and rinsed out chemical bottles (which must be rinsed at least three times and their labels defaced) are usually considered to be non-hazardous. Waste is hazardous if it contains substances that are harmful to the human health or the environment. Hazardous waste must not be disposed of in the general waste stream or via the drain; instead it must be segregated, treated and disposed of by an appropriate hazardous waste management service. It is the responsibility of all lab workers to ensure the safe and correct disposal of all laboratory wastes produced in the course of their work. Improper and irresponsible disposal of chemical waste down drains, in normal bins or into the atmosphere is forbidden by law and can lead to severe consequences for the human health and the environment.

Best practices to reduce your lab waste

Before thinking about how to dispose of chemical waste, you should try to analyse the laboratory’s internal procedures to see if there are ways to reduce the amount of waste produced. To do that, you can look at purchasing procedures. For example, you can buy only what is needed, reducing wastage due to expiry. You can also try to find a reliable supplier who will deliver small amounts of chemicals at short notice. Another good way of reducing waste is considering a centralised purchasing programme to take advantage of bulk pricing. In addition to all that, it may be useful to separate waste into different streams for treatment, reuse or disposal.

Best practices to reuse your lab waste

Reusing something is often the best way of reducing waste, and this can be applied to lab waste too. Try to incorporate recovery activities during the experiments or think about a chemical swap with other institutions in your area, who may be able to take advantage of your left-over chemical products. If reusing is not an option, all waste should be segregated based on chemical incompatibilities e.g. hazardous and non-hazardous wastes should not be mixed together. The same is true of organic and inorganic waste. Waste consisting of the same material type can be segregated and waste streams that are capable of being recycled should be stored separately.

Best practices to recycle laboratory waste

General laboratory waste which is or may be contaminated must be treated to make it safe (using an appropriate method) prior to recycling.

1. All wastes should be segregated based on chemical incompatibilities e.g. hazardous vs. non-hazardous wastes, organic vs. inorganic waste.

2. Make sure the recycling bin is labelled clearly by placing a label on the bin, ensuring that hazardous wastes such as chemicals are not placed in the bin.

3. Bins for the collection of hazardous materials should be placed in the lab. These should be emptied regularly and looked after by lab workers.

4. Where appropriate and safe, containers (e.g. cans, bottles) which previously contained chemicals or otherwise hazardous materials, should be rinsed and made safe for disposal. In these instances, it is necessary to indicate that the container has been made safe by removal or defacing of the contents label.

5. Clean recyclable material which has been identified clearly as non-hazardous should be recycled using appropriate bins.

6. Waste streams that can be recycled should be stored separately i.e. recoverable metals or solvents.

How to dispose of lab waste

Packaging, labelling and storage are the three requirements for disposing of chemical waste.

1. Packaging Laboratory wastes must be stored in containers compatible with the chemicals stored, which should only be filled up to 75% capacity to allow for vapour expansion and to reduce potential spills that can occur from moving overfilled containers. Chemical wastes must not be packaged in containers that improperly identify other non-existent hazards. Glass containers have traditionally been the most resistant to chemical action, but they can break easily. Metal containers are sturdier than glass, but often are corroded by their contents. Various chemically resistant plastic containers are becoming preferable substitutes for glass or metal containers. Safety cans, metal or plastic, should be considered for holding flammable solvents. Incompatible materials should never be mixed together in a single container. Solvent safety cans should be used to collect and temporarily store large volumes (10–20 litres) of flammable organic waste solvents. Precipitates, solids or other non-fluid wastes should not be mixed into safety cans. Lab glassware is not suitable for recycling, as its melting point is higher than that of conventional glass. Broken glassware should be collected in puncture proof containers and disposed of in large containers by technical staff. Biological waste such as agar plates, waste from dissections etc. should be separated and collected separately. Where appropriate this can be autoclaved.

2. Labelling It is essential to label all containers with the group name from the chemical waste category and an itemized list of the contents which should enable knowledgeable laboratory workers to evaluate the hazard. When compatible wastes are collected in a common container, it is advisable to keep a list of the components to help for later disposal decisions. All waste must be appropriately packaged and the labelling must be clear and permanent. Sharp items such as syringes and scalpel blades should be collected in containers labelled "Sharps".

3. Storage When storing chemical wastes, the containers must be in good condition and should remain closed unless waste is being added. Hazardous waste must be stored safely prior to removal from the laboratory and should not be allowed to accumulate. It is essential to segregate incompatible hazardous wastes, such as acids and bases. All liquid waste must be stored in leakproof containers with a screw- top or other secure lid. If necessary, transfer waste material to a container that can be securely closed. Secondary containment should be in place to capture spills and leaks from the primary container.

All Waste Matters offer specialist laboratory waste disposal services to an extensive client base throughout the UK. We can provide a tailored laboratory waste disposal and collection service of any unwanted chemicals to school, colleges and universities offering complete peace of mind and ensuring the lab waste is treated in – keeping and exceeding all recommended guidelines.