Thioacetamide (CAS 62-55-5): storage and disposal
Thioacetamide is a white solid that turns up in school, college and university stores as legacy stock from old analysis schemes. It may cause cancer, is harmful if swallowed, irritates skin and eyes and is harmful to aquatic life with long lasting effects. A jar that nobody has used for years, with a faded label and no record, is the typical find, and it is exactly the sort that needs careful handling.
- CAS number
- 62-55-5
- Form
- Solid
- Storage class
- Toxic
- Signal word
- Danger
- Usual EWC code, laboratory stock
- 16 05 06*
Harmful or irritant
Serious health hazard
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
The cancer classification decides where it goes. Keep thioacetamide in a locked cabinet with a stock record, away from food and drink areas, and away from acids and oxidisers, because toxic stock and oxidising stock are stored apart, and acid contact can release toxic hydrogen sulfide gas. Because this is legacy stock, the first job is to find out whether a record exists: who owns the jar, when it arrived and who last handled it. Put the jar on a tray, keep the lid tight and avoid moving it more than necessary. Staff should know what it is before they open that cabinet.
How to tell it has deteriorated
An old jar shows its age through the container and label more than the powder. Check for a faded, stained or peeling label, a cap thread coated in powder, a lid that has seized, a cracked jar and damp patches on the crystals. A faint sulphurous smell around a cupboard can point to a jar that is not sealing, though we cannot say how strong it will be. Because this solid gives few other visible signs of age, a jar with no label, no date and no stock record is treated as unknown legacy stock. 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 We do not publish a drain or general waste route for any chemical.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.
Say clearly that it is a cancer-classified legacy chemical when you ask for a collection, and give what you know about the jar: size, weight, the label wording including ethanethioamide if printed, and the condition of the lid. Waste code 16 05 06* is the usual description, with 16 05 08* for a discarded organic chemical outside a pack. It goes into a lab pack with compatible solids, away from acids and oxidising stock. It is never washed into a sink, put in the bin or burned, and nobody should dissolve or treat what is left in the jar.
| Usual EWC code, laboratory stock | 16 05 06* |
|---|---|
| Discarded organic chemical, not a laboratory pack | 16 05 08* |
| 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.
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
- H302 Harmful if swallowed.
- H315 Causes skin irritation.
- H319 Causes serious eye irritation.
- H350 May cause cancer.
- H412 Harmful to aquatic life with long lasting effects.
Precautionary statements
- P203 Obtain, read and follow all safety instructions before use.
- 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.
- P273 Avoid release to the environment.
- P280 Wear protective gloves, protective clothing, eye protection and face protection.
- P301+P317 IF SWALLOWED: Get medical help.
- 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.
- P318 If exposed or concerned, get medical advice.
- 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
We found an unlabelled jar that might be thioacetamide. What do we do?
Do not open it to check. Leave it in a tray in the locked cabinet, note where it was found and what you can read on it, and tell the collector it is unidentified legacy stock so it can be described correctly.
Why is thioacetamide still in so many school stores?
It comes from old analysis schemes and was rarely used up. Many stores have a single jar that outlived the practicals it was bought for. The record should say that it is legacy stock.
Can thioacetamide share a cabinet with acids?
No. Toxic stock is stored apart from acids and from oxidisers. Keep it in the locked cabinet with a stock record, and keep acids low down in a separate corrosive store.
Is a small amount left in a jar still hazardous waste?
Yes. It is classified as capable of causing cancer, so even a trace in a jar is declared with the jar. Keep the lid on and do not rinse or scrape it out.
