Thymol (CAS 89-83-8): storage and disposal
Thymol is a white crystalline solid with a strong medicinal smell, kept in school and university stores, histology benches, pharmacies and dental surgeries as an antiseptic or preservative. It is harmful if swallowed, causes severe skin burns and eye damage and is toxic to aquatic life. The smell gives away a leaking jar, and the state of the crystals tells you how warm the cupboard has been.
- CAS number
- 89-83-8
- Form
- Solid
- Storage class
- Corrosive
- Signal word
- Danger
- Usual EWC code
- 16 05 06*
Corrosive
Harmful or irritant
Hazardous to the environment
What to do this week
- Check the label is readable and write down the opened date if it is not already there.
- Check it is stored as corrosive stock and apart from the items listed under "Do not store with".
- 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
In a school prep room thymol tends to sit on a shelf of organic crystals near the windows or pipework, which is the wrong spot. It is a low melting solid, so a warm cupboard or a shelf above a radiator fuses the crystals into a lump and may soften them completely. It belongs low down in a ventilated corrosive store, on a resistant tray, with the lid tight so the smell stays in. Keep it apart from oxidisers and store it separately from flammable solvents, in suitable chemical-resistant containment. Dental and pharmacy holders should label the jar as chemical stock and not as a preparation.
How to tell it has deteriorated
Sound stock is a clean, white or colourless crystalline mass that breaks up freely, with a distinct thyme-like smell inside the closed jar. Trouble starts with fused crystals, a solid cake, or crystals that have run together at the base after warmth. A smell strong enough to notice in the cupboard or room means the seal has failed. A crust at the neck, sticky patches on the shelf, a cap fused to the glass and a yellow or brown tint are further signs, along with labels that are faded or stained. A jar with fused contents or a stuck cap is left closed and recorded as it stands.
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 corrosive other laboratory pack with compatible chemicals.
Collection by a specialist carrier is the route, with the jar packed in a lab pack alongside compatible organic solids. Waste code 16 05 06* fits a lab pack, 16 05 08* a discarded organic chemical outside one, and 18 01 06* a dental surgery or pharmacy in a human healthcare setting. Describe the jar honestly: how much is left, whether the crystals are fused and whether the smell escapes. Its harm to aquatic life is why the jar must never be rinsed out or emptied away, and nobody should try to melt, burn or treat leftovers to get the crystals out.
| EWC code, laboratory chemicals | 16 05 06* |
|---|---|
| Discarded organic chemical, not a laboratory pack | 16 05 08* |
| Human healthcare setting | 18 01 06* |
| Hazardous waste | Yes |
The code depends on where the waste came from and what it is mixed with. Use the waste code finder to see why.
Do not store with
- FlammableA leak of corrosive stock can break down flammable containers and feed a fire.
- OxidiserCorrosive stock can react with oxidisers, releasing heat or fumes.
Named chemicals to keep apart
- AcetoneA leak of corrosive stock can break down flammable containers and feed a fire.
- Calcium hypochloriteCorrosive stock can react with oxidisers, releasing heat or fumes.
- EthanolA leak of corrosive stock can break down flammable containers and feed a fire.
- HexaneA leak of corrosive stock can break down flammable containers and feed a fire.
- Hydrogen peroxideCorrosive stock can react with oxidisers, releasing heat or fumes.
- MethanolA leak of corrosive stock can break down flammable containers and feed a fire.
- Potassium nitrateCorrosive stock can react with oxidisers, releasing heat or fumes.
- Potassium permanganateCorrosive stock can react with oxidisers, releasing heat or fumes.
Show 1 more
- TolueneA leak of corrosive stock can break down flammable containers and feed a fire.
Common quantities we collect
Usually held as: crystals.
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.
- H314 Causes severe skin burns and eye damage.
- H411 Toxic to aquatic life with long lasting effects.
Precautionary statements
- P260 Do not breathe dust, fume, gas, mist, vapours or spray.
- P264 Wash hands and exposed skin thoroughly after handling.
- 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.
- P301+P330+P331 IF SWALLOWED: Rinse mouth. Do NOT induce vomiting.
- P302+P361+P354 IF ON SKIN: Take off immediately all contaminated clothing. Immediately rinse with water for several minutes.
- P304+P340 IF INHALED: Remove person to fresh air and keep comfortable for breathing.
- P305+P354+P338 IF IN EYES: Immediately rinse with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
- P316 Get emergency medical help immediately.
- P321 Specific treatment (see supplemental first aid instruction on this label).
- P330 Rinse mouth.
- P363 Wash contaminated clothing before reuse.
- P391 Collect spillage.
- 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
Why has our thymol turned into a solid lump?
It melts at a low temperature, so warmth in the cupboard fuses the crystals together. The lump is still thymol and is collected as it is. Do not heat the jar or chip at the mass, and record the state at booking.
Can a dental surgery put a small jar of thymol in clinical waste?
No. A small jar is still a chemical waste that causes severe burns and is toxic to aquatic life. It goes by specialist collection, described accurately, under the human healthcare code if that is where it was held.
We can smell thyme in the store but no jar looks damaged. What does that mean?
A seal somewhere is letting vapour out, even if the glass looks sound. Check the jars visually without opening or disturbing them. If a seal is suspected of leaking, or a jar is old, fused or stained at the neck, record its condition and arrange specialist assessment or collection.
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