Butanoic acid (CAS 107-92-6): storage and disposal
Butanoic acid is held neat as a liquid in school and college prep rooms and university labs. It causes severe skin burns and eye damage. Its smell is the most obvious thing about it: a strong, rancid, vomit-like odour that carries through a store room and gives away a leak long before anyone sees one. That makes the cap and the ventilation the first things to check.
- CAS number
- 107-92-6
- Form
- Liquid
- Storage class
- Acid
- Signal word
- Danger
- Usual EWC code, laboratory stock
- 16 05 06*
Corrosive
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 acid 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 small glass bottle with a screw cap is the usual form, and the cap is what matters, because the smell escapes through the thread. Keep the bottle low down on an acid-resistant tray in a ventilated corrosive store, away from alkalis and oxidisers, and put it in a tray deep enough to hold it if it cracks. Acids and alkalis react with strong heat and spattering if they meet. Because the smell travels, a store room next to a staff area or a corridor will get complaints, and a bottle that is bagged or boxed with other items will taint them.
How to tell it has deteriorated
A bottle that has a normal cap and a clean neck is what normal looks like, and the first sign of trouble is the smell. Butanoic acid has a strong rancid odour, so a store that smells of it has a bottle that is leaking vapour or liquid. Look for a perished or brittle cap, crust around the neck, damage to nearby fittings and a cracked container. The liquid gives few visible changes with age. A staff complaint about a smell near the store should be treated as an early warning. A bottle with a failed or leaking cap should be left upright and listed for collection.
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 We do not publish a drain or general waste route for any chemical.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 corrosive acid laboratory pack with compatible chemicals.
It leaves the site only by specialist collection, and a sink, drain, bin or skip is never an option. It must not be diluted or neutralised to reduce the smell. Tell the booking team that the bottle smells strongly, so the collector can plan packing and transport. Record the volume left, the condition of the cap and whether the neck is crusted. A discarded organic chemical outside a lab pack usually takes the code 16 05 08*, and the producer confirms the classification. The collector packs it with other organic acids, apart from alkalis and oxidisers.
| 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
- FlammableSome acids, especially oxidising acids, can ignite flammable materials, and acid fumes attack containers and seals.
- AlkaliAcids and alkalis react with strong heat and spattering if they meet.
- OxidiserMany oxidisers release toxic gas or become unstable in contact with acid.
- ToxicToxic stock is stored apart from acids. Several toxic salts release toxic gas in contact with acid.
Named chemicals to keep apart
- AcetoneOxidising acids can ignite flammable materials, and acid fumes attack containers and seals.
- Ammonia solutionAcids and alkalis react with strong heat and spattering if they meet.
- Calcium hypochloriteMany oxidisers release toxic gas or become unstable in contact with acid.
- EthanolOxidising acids can ignite flammable materials, and acid fumes attack containers and seals.
- FormalinToxic stock is stored apart from acids. Several toxic salts release toxic gas in contact with acid.
- HexaneOxidising acids can ignite flammable materials, and acid fumes attack containers and seals.
- Hydrogen peroxideMany oxidisers release toxic gas or become unstable in contact with acid.
- Mercury(II) chlorideToxic stock is stored apart from acids. Several toxic salts release toxic gas in contact with acid.
Show 7 more
- MethanolOxidising acids can ignite flammable materials, and acid fumes attack containers and seals.
- Potassium hydroxideAcids and alkalis react with strong heat and spattering if they meet.
- Potassium nitrateMany oxidisers release toxic gas or become unstable in contact with acid.
- Potassium permanganateMany oxidisers release toxic gas or become unstable in contact with acid.
- Sodium cyanideToxic stock is stored apart from acids. Several toxic salts release toxic gas in contact with acid.
- Sodium hydroxideAcids and alkalis react with strong heat and spattering if they meet.
- TolueneOxidising acids can ignite flammable materials, and acid fumes attack containers and seals.
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
- H314 Causes severe skin burns and eye damage.
Precautionary statements
- P260 Do not breathe dust, fume, gas, mist, vapours or spray.
- P264 Wash hands and exposed skin thoroughly after handling.
- P280 Wear protective gloves, protective clothing, eye protection and face protection.
- 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).
- 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 does our prep room smell of rancid butter?
Butanoic acid has a strong rancid odour that escapes through a loose or worn cap. Check the caps and necks of acid bottles, keep the store ventilated and list any bottle with a loose, worn or leaking cap for collection.
Is there a way to cut the smell from leftover liquid before collection?
No. Leftover liquid must not be neutralised or diluted. Keep the bottle capped and upright on its tray, record the smell and the cap condition, and ask for a collection.
Where should neat butanoic acid be kept in a school?
Low down on an acid-resistant tray in a ventilated corrosive store, away from alkalis and oxidisers, and away from corridors and staff areas where the smell would be noticed. Keep the cap clean and fully seated.
