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Chemical collection and stock control for UK schools, universities and hospitals

Ethylene glycol (CAS 107-21-1): storage and disposal

Ethylene glycol is held neat in school, college and university stores and in histology labs, where it also turns up inside mounting and cryoprotectant mixes. It is a colourless, sweet tasting liquid that is harmful if swallowed and damages the kidneys. That taste is the reason labels and security carry more weight here than any special shelf.

CAS number
107-21-1
Form
Liquid
Storage class
General
Signal word
Warning
Usual EWC code
16 05 06*
  • Harmful or irritant pictogramHarmful or irritant

What to do this week

  1. Check the label is readable and write down the opened date if it is not already there.
  2. Check it is stored as general stock and apart from the items listed under "Do not store with".
  3. If you no longer need it, add it to your disposal list so it goes on the next collection.

Safe storage in a school or lab

Harmful if swallowed, damaging to the kidneys and sweet tasting: those facts decide where it goes. A labelled bottle belongs in a lockable cupboard with a stock record, away from food and drink areas, and never decanted into drinks bottles or unlabelled pots. Beyond that it is general stock, so a dry, well organised store is enough. Antifreeze containers brought in from a vehicle workshop should be kept apart from laboratory bottles. Mixes held for cryoprotection in a histology lab need their own label naming the contents and the date, since the glycol is no longer obvious once it is part of a mix.

How to tell it has deteriorated

Sound stock is a clear, colourless, slightly syrupy liquid in a labelled bottle with a clean neck. It takes up moisture from the air, so a bottle opened many times may run thinner than it once did, and a cap left loose often has a sticky ring. What does not look right is a bottle with its label gone, a clean looking bottle in an unexpected place such as a staff room or a workshop shelf, or a cloudy liquid, a floating layer or sediment that suggests another product has been added. Treat any of those as unknown stock and keep the bottle secure and closed.

How it must be disposed of

By specialist collection only. It never goes down the drain or into general waste. It is normally packed in a non-regulated or low hazard laboratory pack with compatible chemicals.

Waste code 16 05 06* applies to a bottle packed in a lab pack, and the asterisk shows it is handled as hazardous waste because it is harmful if swallowed and damages the kidneys. A discarded organic chemical outside a lab pack takes 16 05 08*, and a histology lab in a human healthcare setting uses 18 01 06*. Mixes with other ingredients are described from their label. The only route is specialist collection. The liquid must not go to a drain, a bin or a skip, and a sweet tasting chemical must never be left in an open container waiting for pickup.

Waste codes and transport details for Ethylene glycol
EWC code, laboratory chemicals16 05 06*
Discarded organic chemical, not a laboratory pack16 05 08*
Human healthcare setting18 01 06*
Hazardous wasteYes

The code depends on where the waste came from and what it is mixed with. Use the waste code finder to see why.

Common quantities we collect

Usually held as: neat, mounting and cryoprotectant mixes.

Part-used bottles and full containers are both fine. Tell us the size and how many, and an estimate is enough for a first price.

Where it is commonly held

Hazard statements

  • H302 Harmful if swallowed.
Precautionary statements
  • P264 Wash hands and exposed skin thoroughly after handling.
  • P270 Do not eat, drink or smoke when using this product.
  • P301+P317 IF SWALLOWED: Get medical help.
  • P330 Rinse mouth.
  • P501 Dispose of contents and container in accordance with local, regional, national and international regulations.

Substance as classified, dilutions may differ.

Questions

Why is a liquid that is only harmful if swallowed kept locked up?

Because it is sweet tasting and damages the kidneys, so a mistaken drink would do real harm. Keeping it labelled, locked and recorded matters more here than any special shelf. Note who holds the key.

Can workshop antifreeze go with our laboratory collection?

If it is held on site as chemical stock, tell us what it is. Vehicle antifreeze may carry other ingredients, so describe it from the product label, give the amount, and say if it has been decanted.

How is a cryoprotectant mix described for collection?

By its label and recipe record. A mix carrying ethylene glycol takes its description from everything in it, so list the components you know, keep it in a closed labelled bottle and say if the contents are uncertain.

Which code does a histology lab use?

A histology lab in a human healthcare setting uses 18 01 06*, while a university store uses 16 05 06* in a lab pack. State where the bottle was held when booking and the team will confirm the code.

Guidance only. Check your own risk assessment and your supplier's safety data sheet.

Hazard data source: PubChem GHS Classification, retrieved 31 Oct 2026. Formula C2H6O2. EC number 203-473-3.

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