Chemical waste for industrial laboratories

QC, R&D, analytical and contract testing labs all produce small quantities of waste with a very specific history. Typical lists include:

• HPLC mobile phase waste, often acetonitrile or methanol in water with modifiers
• used titrants, buffers and Karl Fischer reagents
• COD, heavy metal and other test kit vials
• expired analytical standards and calibration solutions
• part-used reagents from withdrawn methods
• retained product and raw material samples past their retention period

Anything flagged as unstable, explosives, radioactive sources including those in older analytical instruments, gas cylinders, asbestos and controlled drugs go to a manual enquiry. Hydrofluoric acid, which some labs use for digestion or etching, is also handled as a manual enquiry, because of how dangerous it is to handle and contain.

We are not the right fit for tanker loads or production clean-outs. Lab packs make sense when there are many different containers and modest weight.

• a list of chemicals, with quantities and container sizes, by laboratory if there are several
• for mixed solvent streams, the method name and an estimated composition
• safety data sheets for formulated products and retained samples
• whether containers are original supplier packaging, or decanted or reused
• gatehouse, induction and permit-to-work requirements for visiting contractors
• the site contact who will sign, and the person holding the purchase order

Sites with a formal contractor induction should tell us early. A chemist who has to pack in your laboratory may need your permit to work, and building that in from the beginning prevents a wasted visit.

The coding of laboratory chemicals depends on the source and the order in which you check the chapters. The technical guidance on waste, WM3, asks you to start with chapters 01 to 12 and 17 to 20, which describe the industry or process. You then check chapters 13 to 15, including waste solvents, and turn to chapter 16 last.

That order means an industrial lab may legitimately use more than one family of codes. Lab chemicals from QC work often fall under 16 05 06*, discarded inorganic and organic chemicals under 16 05 07* and 16 05 08*, and collected solvents under 14 06 02* or 14 06 03*. Some wastes will belong under a process chapter, because they came from a sector-specific activity. This is why a QC lab in a paint plant may not code its wastes the same way as a contract lab testing water.

Part B of a consignment note requires the SIC code of the process and a full written description, including components and concentrations. The short List of Waste wording is not normally enough. If most of the lab's waste comes from one method, you can set out a standard description once and use it every time.

Industrial labs generate a kind of legacy stock that schools and hospitals rarely have. A method is revalidated and an old reagent is no longer specified. An auditor asks why a standard is three years past its date. A customer drops a product line, and years of retained samples lose their purpose all at once.

Treat a method change as a disposal trigger. At that moment, somebody knows exactly what the reagent is and why it was bought. Removing it then also keeps it out of your next audit's findings and your COSHH inventory. HSE's assessment guidance covers everyone who may be exposed, including maintenance staff and contractors, and a store full of unneeded chemicals adds to that picture for no benefit.

Retained samples are worth a separate look. Paints, resins, adhesives and formulated products may be in the thousands, each with a tiny quantity and a data sheet held by someone in another department. They are not always hazardous, and you must classify each before it leaves. A table of product families, each with its safety data sheet, is usually the most efficient way to describe them. Do not ask a carrier to work from individual batch numbers.

Some of the most hazardous waste in an industrial lab is the smallest. COD test vials commonly contain sulfuric acid with dichromate, silver and mercury salts, and they are often kept in a rack because they look harmless. Used vials should be treated as hazardous waste, kept closed and kept together. Do not open them to reclaim the glass.

Older Karl Fischer reagents may contain pyridine. Waste from these titrators also tends to contain methanol, iodine and sulfur dioxide together, so it should have its own container. Trifluoroacetic acid in HPLC waste changes the character of what looks like a simple aqueous solvent stream. Halogenated solvents from an extraction method should not be sent down the same line as acetonitrile waste, as the segregation guidance treats mixes that affect disposal options as prohibited. Our solvent waste collection page goes further into how to set up those lines.

Laboratory waste bottles should also not be connected to unattended instruments without thinking about what happens overnight or at a weekend. An overfilled carboy of flammable waste under a bench is a DSEAR matter.

Labs on larger sites often assume the environmental team has this covered, and the environmental team often assumes the lab does. Someone needs to own it. The waste duty of care applies to the business producing the waste, and it expects you to check that those taking it are authorised, and where it is going.

Tenant labs need particular clarity. If you occupy space on another company's site, you may be a separate producer, and your waste should not be added to your landlord's consignments without agreement. A contract testing lab handling customer samples also needs to decide, in its own terms, who owns any leftover material.

Keep your documents together. In England, consignment notes and consignee returns stay at the premises for three years, and an environmental audit will usually ask to see them next to the classification evidence. If your site holds an environmental permit or a management system certificate, your own procedures may ask for more than the minimum.