Laboratory chemical disposal

Almost anything a working laboratory holds in small containers can be priced from a list. That covers surplus and expired reagents, teaching solutions, organic and inorganic chemicals, stains and indicators, solvents and spent method waste. Schools send long lists of small bottles, research groups send unusual compounds in tiny quantities, and hospital laboratories send regular fixative and solvent streams.

Five groups do not follow that route: controlled drugs, radioactive sources, explosives (including dried picric acid and other chemicals flagged as unstable), compressed gas cylinders and asbestos. They go to a manual enquiry, usually together with a recommendation for a chemical store assessment. Unknown substances that cannot be placed with confidence join them. Nothing about this is unusual. These items simply need someone's judgement before any price is meaningful.

• chemical names, with CAS numbers if you have them
• quantity and container size per line, and number of containers
• concentration, for anything in solution
• condition notes, such as a seized cap, leakage, crystals or a damaged label
• a list of anything that may need a manual enquiry, kept separate
• site access, parking and working-hours restrictions
• the name of the person who will sign the consignment note

A spreadsheet is ideal, but a handwritten stock book is enough to start, and the first conversation usually shows whether a site visit is needed before any bottles move.

A lab pack is a common way of moving small chemical containers. Bottles of compatible chemicals are placed inside an outer drum or box that is approved for transporting dangerous goods. Absorbent, cushioning material fills the gaps, so a broken inner bottle stays contained and does not move around. The drum is labelled, sealed and described on the transport paperwork.

The compatibility step is what makes the job skilled work. A chemist, usually working from your list and then checking each bottle, sorts stock by transport class and chemical reactivity. GOV.UK's guide to moving dangerous goods lists these classes, including flammable liquids, oxidising substances, toxic substances and corrosives, and puts responsibility on the consignor or sender to classify, package and mark them. Oxidisers do not go with organics. Acids do not go with alkalis or cyanides. Water-reactive chemicals go somewhere dry and apart.

This is also the reason a small list can produce several drums. Fifty bottles may need five packs if they span five hazard groups, and four of those packs may be only partly full. Weight does not drive the cost the way people expect. The number of incompatible groups often matters more.

Packing normally happens on your site, at a bench or a clear floor area. Permitted facilities are also told to sort and segregate laboratory smalls at source wherever possible, so that containers do not need to be reopened or re-sorted later.

Keeping things apart is both a chemical precaution and a legal requirement. GOV.UK states that hazardous waste must not be mixed with non-hazardous waste, with non-waste, or with other categories of hazardous waste. Categories are defined by what would happen if you mixed them, and not by the code. Its own example is telling: an acid and an alkali are different categories even when both carry 16 05 06*.

Mixing also includes dilution. A mixture that reduces a hazardous property by dilution, removes a recovery option, or hides a component from the next holder is the wrong side of the line. It does not matter how tidy the result looks. Bottles sitting in the same crate are a different matter, provided they are not physically mixed, cross-contamination cannot occur and each is separately described, because the guidance treats that as co-collection.

WM3, the technical guidance on waste, uses this very situation as an example. A crate containing bottles of three different laboratory chemicals holds three wastes, each assessed separately.

Six-digit List of Waste codes, also called EWC codes, depend on where the waste came from as well as what it is. A school or university preparation lab commonly uses 16 05 06* for laboratory chemicals containing hazardous substances. A hospital lab has chapter 18 to look at first, with 18 01 06* for hazardous chemicals. A veterinary lab looks at 18 02 05*. Photochemicals sit in chapter 09 wherever they come from. Collected solvents usually fall under 14 06 02* or 14 06 03*.

The asterisk marks a hazardous entry. Where there is a choice between a hazardous and a non-hazardous entry for the same material, you must assess it, and WM3 says that waste with a mirror entry whose composition genuinely cannot be established takes the hazardous entry. A safety data sheet helps, but only for the chemical as supplied, and it says little about a working solution that has been used and contaminated.

A good list answers the questions a chemist would ask on the phone. What is it? How much? What is it in, and what state is it in? Rows that answer those four questions can be priced almost immediately.

The problems come from vagueness that hides risk. Mixed chemicals is not a description. Solvents could mean ten litres of acetone or ten litres of chloroform and acetone together, which are very different jobs. A note that a bottle has crystals round the neck changes everything about how it is handled, and we would far rather have it than a clean-looking list that leaves it out.

Unidentified bottles do not stop a list being priced. They are priced differently, once someone has seen them, and they do not hold up the known stock if they can be kept apart.

In England, you must classify your waste, store it safely, use authorised businesses, complete your parts of the consignment note and keep your records for three years at the premises. We prepare the paperwork and send it for your check, but the description is yours. The duty of care code of practice defines a broker as someone who arranges the transport and management of waste on behalf of another party, and it makes clear that using one does not remove your own duties.

Wales has its own consignment code format and registration of premises above 500kg a year. Scotland uses a special waste consignment note with a code issued by SEPA. Northern Ireland has its own system, and collections there are a manual enquiry for now.

Two reforms are worth knowing about, though neither changes your duties as a producer today. Digital waste tracking has been mandatory for receiving site operators in England and Wales since 1 October 2026. Government plans extend it to Scotland and Northern Ireland from January 2027, and to waste collectors from October 2027. Defra has also announced that the registration system for carriers, brokers and dealers will move to permits during 2027. Consignment notes remain in use in the meantime.