Acetic acid (CAS 64-19-7): storage and disposal
Acetic acid turns up in school and college prep rooms, university labs, pathology and histology departments and clinics, usually as glacial stock with 1 M and 2 M solutions beside it. Glacial stock is a flammable liquid and also causes severe skin burns and eye damage. It is both an acid and a fire risk, so the shelf it sits on and the nitric acid and chromates nearby decide how it is held and collected.
- CAS number
- 64-19-7
- Form
- Liquid
- Storage class
- Acid
- Signal word
- Danger
- Usual EWC code
- 16 05 06*
Flammable
Corrosive
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 acid 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
Look at the glass first: glacial stock freezes in a cold store, and frozen liquid can crack the bottle. It is flammable and corrosive, so it needs a ventilated place with spill containment, away from ignition sources and from oxidisers, rather than the ordinary acid shelf. Nitric acid and chromium trioxide must be kept apart from it, since nitric acid reacts violently with organic liquids and chromium trioxide can ignite them. Concentrated hydrogen peroxide, perchloric acid, hypochlorites and sulfides need other spaces. Store the 1 M and 2 M solutions according to their own hazard classification, rather than assuming they need the same arrangements as flammable glacial stock.
How to tell it has deteriorated
Start with the bottle and its label. Cracked glass, perhaps after the contents froze in a cold store, is the most specific warning. Then look for a lower level, which suggests vapour has escaped, bulging or sucked-in containers, leaking seals, stained labels, perished caps and crust around the neck. Fumes on opening and corrosion of nearby fittings are further signs. Weaker solutions look like water, so for those the label and cap matter most. Anything with a cracked container, a damaged closure or no readable strength should be left where it is and listed for collection, and not shifted to a different cupboard.
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 acid laboratory pack with compatible chemicals.
Before asking for a collection, record whether each container holds glacial stock or a 1 M or 2 M solution, its fill level and any cracks or damaged caps. Specialist collection is the only route. It must never go into a sink, a drain, a general waste bin or a skip, and it should not be evaporated, burned, diluted or neutralised first. Because the acid is organic as well as corrosive, the code to quote is 16 05 08* for a discarded organic chemical that is not in a lab pack. A bottle that has frozen and cracked is awkward to lift, so say so when you book. Keep the consignment paperwork you are given.
| 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 |
20 01 13* (solvents) belongs to municipal collections and is shown for reference only. It is not the normal code for a laboratory collection.
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
- FlammableOxidising 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.
- Ammonium sulfide solutionSulfides release toxic hydrogen sulfide gas with acids.
- Calcium hypochloriteHypochlorites release toxic chlorine gas in contact with acids.
- Chloramine THypochlorites release toxic chlorine gas in contact with acids.
- Chromium trioxideChromium trioxide can ignite organic liquids on contact.
- 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.
Show 16 more
- HexaneOxidising acids can ignite flammable materials, and acid fumes attack containers and seals.
- Hydrogen peroxideConcentrated peroxide with these liquids can form unstable organic peroxides.
- Iron(II) sulfideSulfides release toxic hydrogen sulfide gas with acids.
- Nitric acidNitric acid reacts violently with organic solvents and can ignite them or build pressure in waste bottles.
- Perchloric acidPerchloric acid forms explosive mixtures with organic material.
- Potassium chlorateChlorates and strong acids can form explosive chlorine dioxide.
- Potassium cyanideCyanides release highly toxic hydrogen cyanide gas with acids.
- Potassium ferricyanideHeating or strong acids can release toxic hydrogen cyanide from these complexes.
- Potassium ferrocyanideHeating or strong acids can release toxic hydrogen cyanide from these complexes.
- Sodium azideAzides release highly toxic and explosive hydrazoic acid with acids.
- Sodium chlorateChlorates and strong acids can form explosive chlorine dioxide.
- Sodium cyanideCyanides release highly toxic hydrogen cyanide gas with acids.
- Sodium dichloroisocyanurateHypochlorites release toxic chlorine gas in contact with acids.
- Sodium hypochloriteHypochlorites release toxic chlorine gas in contact with acids.
- Sodium nitriteNitrites release toxic nitrogen oxides with acids.
- Sodium sulfideSulfides release toxic hydrogen sulfide gas with acids.
Common quantities we collect
Usually held as: glacial, 1 M, 2 M.
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
- H226 Flammable liquid and vapour.
- H314 Causes severe skin burns and eye damage.
Precautionary statements
- P210 Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
- P233 Keep container tightly closed.
- P240 Ground and bond container and receiving equipment.
- P241 Use explosion-proof electrical, ventilating and lighting equipment.
- P242 Use non-sparking tools.
- P243 Take action to prevent static discharges.
- 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.
- P303+P361+P353 IF ON SKIN (or hair): Take off immediately all contaminated clothing. Rinse skin with water or shower.
- 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.
- P370+P378 In case of fire: Use suitable extinguishing media to extinguish.
- P403+P235 Store in a well-ventilated place. Keep cool.
- 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
Can glacial acetic acid go in the fridge or a cold store?
Not safely. Glacial stock freezes in a cold store, and the frozen liquid can crack a glass bottle. A refrigerator is only suitable if it is spark-free, because the liquid is flammable and corrosive.
Is acetic acid treated as an acid or a flammable liquid?
Both. Glacial stock is flammable and corrosive, so it needs a ventilated place away from ignition sources and oxidisers, as well as away from nitric acid and chromates. Check how your store arrangement covers both risks.
Do weak acetic acid solutions from a practical need specialist collection?
Yes. Weaker solutions may be less hazardous than glacial stock, but they remain chemical waste. They must not go down a sink or into general waste and must not be treated first. List them for specialist collection.
What should we do with a cracked bottle?
Leave it in place on its tray and do not try to transfer the contents. Note the strength and the damage, keep ignition sources away because the glacial liquid is flammable, and ask for specialist advice.
