m-Cresol (CAS 108-39-4): storage and disposal
m-Cresol is a neat liquid held in college and university chemistry stores and in some pharmacies. It is toxic if swallowed or in contact with skin and causes severe skin burns and eye damage. Its strong phenolic smell can escape past a poorly sealed cap, so a room can report a problem before the label does.
- CAS number
- 108-39-4
- Form
- Liquid
- Storage class
- Toxic
- Signal word
- Danger
- Usual EWC code, laboratory stock
- 16 05 06*
Corrosive
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
Acids and oxidisers are the things to keep away from it. Keep m-cresol apart from incompatible acids and oxidising chemicals, because contact can cause hazardous reactions. Give it a locked cabinet with a stock record, away from food and drink areas, with the bottle upright in a tray that would catch a leak. In a pharmacy, it should not sit with finished preparations or with dispensing bench stock, and it should carry a label naming it in full rather than cresol alone. A tight cap stops the smell reaching the room.
How to tell it has deteriorated
Check the cap and label first. A phenolic smell in the cupboard, a sticky or stained neck and a label dissolved by drips all show that liquid has got out. The liquid itself starts clear to pale and tends to darken to yellow or brown with age and exposure to air and light, so a deeply coloured bottle has probably been open or badly sealed for some time. Crystals or crust at the neck show where the liquid has dried. Treat a bottle with any of these signs as a possible leak: leave it standing in its tray, closed, and record what you see.
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 We do not publish a drain or general waste route for any chemical.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.
Before booking, note the exact label wording, the size of the container, how much is left, the colour of the liquid and whether the neck or label is stained. A heavily darkened bottle is still collected as it is. It is packed in a lab pack, usually under 16 05 06*. It may instead be described under 16 05 08* as a discarded organic chemical outside one, or under 18 01 06* in a pharmacy, and the producer confirms the classification. Specialist collection is the only route, and the liquid must not be put down a drain, washed away or treated first.
| Usual EWC code, laboratory stock | 16 05 06* |
|---|---|
| Discarded organic chemical, not a laboratory pack | 16 05 08* |
| Human healthcare setting | 18 01 06* |
| 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: neat.
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.
- H311 Toxic in contact with skin.
- H314 Causes severe skin burns and eye damage.
Precautionary statements
- P260 Do not breathe dust, fume, gas, mist, vapours or spray.
- P262 Do not get in eyes, on skin, or on clothing.
- P264 Wash hands and exposed skin thoroughly after handling.
- 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.
- P301+P330+P331 IF SWALLOWED: Rinse mouth. Do NOT induce vomiting.
- P302+P352 IF ON SKIN: Wash with plenty of water.
- 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.
- P361+P364 Take off immediately all contaminated clothing. And wash it before reuse.
- P363 Wash contaminated clothing 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
Why has our m-cresol gone dark brown?
Cresols tend to darken with age and exposure to air and light, which usually means the bottle has been opened often or the cap has not sealed well. It is still collected. Record the colour and keep the bottle closed.
Can a pharmacy hold it near other raw materials?
Only if it is separated from acids and oxidisers and kept locked with a stock record. It causes severe burns and is toxic by mouth and skin, so it should not share a shelf with finished preparations.
We can smell phenol in the store but see no leak. What should we do?
Treat it as a failing seal. Do not open bottles to find the source. Follow the site's chemical leak procedure without opening, tightening or disturbing suspect bottles. Arrange specialist assessment where a failed seal or leak is suspected.
