Chloral hydrate (CAS 302-17-0): storage and disposal
Chloral hydrate is an old sedative and a mounting medium ingredient, held as legacy stock in university, histology, pharmacy and veterinary stores. It is toxic if swallowed and irritates skin and eyes. It is not a UK controlled drug, though it was once a common medicine, so old bottles often have a pharmacy label and an expiry long past. It absorbs moisture, which is how most old jars go wrong.
- CAS number
- 302-17-0
- Form
- Solid
- Storage class
- Toxic
- Signal word
- Danger
- Usual EWC code, laboratory stock
- 16 05 06*
Acute toxicity
What to do this week
- Without moving anything that looks damaged, check the label is readable and write down the opened date if it is not already there.
- Check it is stored as toxic stock, and apart from anything listed under "Do not store with" on this page. If nothing is listed, that does not prove it is safe with everything.
- If you no longer need it, add it to your disposal list so it can be included in a collection.
Safe storage in a school or lab
A glass bottle with a good stopper is how this material usually arrives, and because it absorbs moisture the stopper must seat firmly. Keep it in a locked cabinet with a stock record, away from food and drink areas and from acids and oxidisers, and on a dry shelf away from wet areas and radiators. A histology lab may hold it among mounting media ingredients, and a pharmacy or veterinary practice among old sedatives, so check the label and record where it came from. Do not return a jar to a damp room after it has been out.
How to tell it has deteriorated
Because it absorbs moisture, old chloral hydrate often changes form. Crystals clump together, turn damp or sticky and may collapse into a wet mass or partly liquid lump at the bottom of the jar. A pungent smell may reach the cabinet, and the stopper can seize. Moisture can stain or lift paper labels, and old pharmacy labels may be missing the expiry. A jar that has gone wet is not unusual, but it should be left sealed, in a locked cabinet on a tray, and recorded accurately, because the contents may leak. Do not open it to check.
How it is disposed of
We arrange this by specialist collection. We do not publish a drain or general waste route for any chemical. It is normally packed in a toxic laboratory pack with compatible chemicals.
It is toxic if swallowed, so a veterinary or pharmacy holder should not treat it as ordinary waste medicine and should not use a medicines return bin. It leaves by specialist collection only, packed with compatible organic solids. Name it as chloral hydrate and say whether the jar is crystalline or damp, and whether it is mounting medium or sedative stock. Laboratory stock fits 16 05 06*, a loose discarded organic chemical can use 16 05 08*, a human healthcare setting 18 01 06*, and a veterinary setting 18 02 05*.
| Usual EWC code, laboratory stock | 16 05 06* |
|---|---|
| Discarded organic chemical, not a laboratory pack | 16 05 08* |
| Human healthcare setting | 18 01 06* |
| Veterinary setting | 18 02 05* |
| Usually classed as hazardous waste | Yes |
The code depends on where the waste came from and what it contains, and classifying it is the producer's duty. Use the waste code finder to see why.
Do not store with
- OxidiserToxic and oxidising stock are stored apart. A reaction could release toxic vapours.
- AcidToxic stock is stored apart from acids. Several toxic salts release toxic gas in contact with acid.
Named chemicals to keep apart
- Acetic acidToxic stock is stored apart from acids. Several toxic salts release toxic gas in contact with acid.
- Calcium hypochloriteToxic and oxidising stock are stored apart. A reaction could release toxic vapours.
- Hydrochloric acidToxic stock is stored apart from acids. Several toxic salts release toxic gas in contact with acid.
- Hydrogen peroxideToxic and oxidising stock are stored apart. A reaction could release toxic vapours.
- Nitric acidToxic stock is stored apart from acids. Several toxic salts release toxic gas in contact with acid.
- Potassium nitrateToxic and oxidising stock are stored apart. A reaction could release toxic vapours.
- Potassium permanganateToxic and oxidising stock are stored apart. A reaction could release toxic vapours.
- Sulfuric acidToxic stock is stored apart from acids. Several toxic salts release toxic gas in contact with acid.
Common quantities
Usually held as: legacy stock, mounting media.
Tell us the container size and how many you hold. An estimate is enough to start with, and some items cannot be priced until someone has looked at them.
Where it is commonly held
Hazard statements
- H301 Toxic if swallowed.
- H315 Causes skin irritation.
- H319 Causes serious eye irritation.
Precautionary statements
- P264 Wash hands and exposed skin thoroughly after handling.
- P264+P265 Wash hands and exposed skin thoroughly after handling. Do not touch eyes.
- P270 Do not eat, drink or smoke when using this product.
- P280 Wear protective gloves, protective clothing, eye protection and face protection.
- P301+P316 IF SWALLOWED: Get emergency medical help immediately.
- P302+P352 IF ON SKIN: Wash with plenty of water.
- P305+P351+P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
- P321 Specific treatment (see supplemental first aid instruction on this label).
- P330 Rinse mouth.
- P332+P317 If skin irritation occurs: Get medical help.
- P337+P317 If eye irritation persists: Get medical help.
- P362+P364 Take off contaminated clothing. And wash it before reuse.
- P405 Store locked up.
- P501 Dispose of contents and container in accordance with local, regional, national and international regulations.
Substance as classified, dilutions may differ.
Questions
Is chloral hydrate a controlled drug?
It is not a UK controlled drug, so the controlled drugs register does not apply. It is still toxic if swallowed, so keep it in a locked cabinet with a stock record and arrange specialist collection.
Our chloral hydrate has turned into a damp lump. Is it usable?
It absorbs moisture, so clumping and a wet mass are typical of old jars. Whether any stock is still suitable for use is a technical decision, but for most legacy jars the right step is to seal them and list them for collection.
Can a vet practice return it through the medicines route?
Do not assume so. It is classified as toxic if swallowed and is not a controlled drug, so the controlled drugs route does not apply. Describe it on a collection request and keep it locked until collected.
