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Chemical collection and stock control for UK schools, universities and hospitals

Ethyl acetate (CAS 141-78-6): storage and disposal

Ethyl acetate is the sweet-smelling ester solvent kept as a neat liquid in school, college and university stores. It is a highly flammable liquid and vapour, causes serious eye irritation and may cause drowsiness or dizziness. A bottle left on a prep room shelf for years is a common find, and its smell is often the first sign that something has changed.

CAS number
141-78-6
Form
Liquid
Storage class
Flammable
Signal word
Danger
Usual EWC code
16 05 06*
  • Flammable pictogramFlammable
  • Harmful or irritant pictogramHarmful or irritant

What to do this week

  1. Check the label is readable and write down the opened date if it is not already there.
  2. Check it is stored as flammable stock and apart from the items listed under "Do not store with".
  3. 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

A prep room with nitric acid or perchloric acid on the next shelf has the worst pairing for this solvent. Nitric acid reacts violently with organic solvents like ethyl acetate and can ignite them or build pressure in waste bottles, and perchloric acid forms explosive mixtures with organic material. Put the solvent in a ventilated fire-resistant cabinet with spill containment, well away from ignition sources, oxidisers and corrosive stock. Only a spark-free refrigerator should hold it if cooling is needed. Keep the cap tight, and record the date opened on every bottle so that long-standing stock can be found at the next clear-out.

How to tell it has deteriorated

A sharp vinegar smell on opening a bottle that once smelt sweet means some of the ester has broken down with moisture to give acetic acid and ethanol. This happens more in bottles left loosely capped in a damp prep room. Level is the other early sign, since a highly flammable liquid in a poorly closed bottle drops steadily. Look for cap liners that have swollen, a stained label, residue round the neck and a bulging or sucked-in container. A vinegar smell in the cabinet itself can point to a bottle that has been leaking, so look at the shelf as well.

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 flammable laboratory pack with compatible chemicals.

The bottles leave by specialist collection, packed into a lab pack with compatible organic solvents and described under waste code 16 05 06*, or 16 05 08* for a discarded organic chemical outside a pack. Record the size, the fill and any vinegar smell, since a bottle that has partly broken down is declared as it stands. Bottles stay away from nitric and perchloric acids until the collector arrives. Pouring it into a sink, tipping it into the bin or leaving it to evaporate is never acceptable.

Waste codes and transport details for Ethyl acetate
EWC code, laboratory chemicals16 05 06*
Discarded organic chemical, not a laboratory pack16 05 08*
Hazardous wasteYes

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

  • OxidiserOxidisers can ignite flammable materials or make a fire far more intense.
  • AcidOxidising acids can ignite flammable materials, and acid fumes attack containers and seals.
  • CorrosiveA leak of corrosive stock can break down flammable containers and feed a fire.

Named chemicals to keep apart

  • Acetic acidOxidising acids can ignite flammable materials, and acid fumes attack containers and seals.
  • Calcium hypochloriteOxidisers can ignite flammable materials or make a fire far more intense.
  • Hydrochloric acidOxidising acids can ignite flammable materials, and acid fumes attack containers and seals.
  • Hydrogen peroxideOxidisers can ignite flammable materials or make a fire far more intense.
  • 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 nitrateOxidisers can ignite flammable materials or make a fire far more intense.
  • Potassium permanganateOxidisers can ignite flammable materials or make a fire far more intense.
Show 3 more
  • Sulfuric acidOxidising acids can ignite flammable materials, and acid fumes attack containers and seals.
  • Thionyl chlorideA leak of corrosive stock can break down flammable containers and feed a fire.
  • Zinc chlorideA leak of corrosive stock can break down flammable containers and feed a fire.

Common quantities we collect

Usually held as: neat.

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

  • H225 Highly flammable liquid and vapour.
  • H319 Causes serious eye irritation.
  • H336 May cause drowsiness or dizziness.
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.
  • P261 Avoid breathing dust, fume, gas, mist, vapours or spray.
  • P264+P265 Wash hands and exposed skin thoroughly after handling. Do not touch eyes.
  • P271 Use only outdoors or in a well-ventilated area.
  • P280 Wear protective gloves, protective clothing, eye protection and face protection.
  • 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+P351+P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
  • P319 Get medical help if you feel unwell.
  • P337+P317 If eye irritation persists: Get medical help.
  • P370+P378 In case of fire: Use suitable extinguishing media to extinguish.
  • P403+P233 Store in a well-ventilated place. Keep container tightly closed.
  • 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

Why does our old ethyl acetate smell of vinegar?

Moisture slowly splits the ester into acetic acid and ethanol, and the acid gives the vinegar smell. The bottle is aged stock. Keep it capped in the cabinet, and declare it as waste with a note about the smell.

Can ethyl acetate be stored next to nitric acid in a prep room?

No. Nitric acid reacts violently with organic solvents and can ignite them or build pressure in waste bottles. Keep them in separate cabinets, with the acid low down on a tray.

Is a spark-free fridge needed for ethyl acetate?

Only if you need to refrigerate it. A highly flammable liquid must not go in an ordinary fridge. Otherwise the fire-resistant cabinet is the normal home, with the cap tight and the date opened written on the label.

What should we record before asking for a collection?

The label name, bottle size, approximate fill, date of receipt or opening, and any smell of vinegar or sign of leaking. That lets the collector group it with compatible organic solvents.

Guidance only. Check your own risk assessment and your supplier's safety data sheet.

Hazard data source: PubChem GHS Classification, retrieved 31 Oct 2026. Formula C4H8O2. EC number 205-500-4.

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