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

Cinnamaldehyde (CAS 104-55-2): storage and disposal

Cinnamaldehyde is the cinnamon-scented aldehyde held as a neat liquid in school, college and university stores. It is harmful in contact with skin, irritates skin and eyes and may cause an allergic skin reaction. The sensitising hazard is the one a technician should remember when handling an old, sticky bottle, because contact on a cap or a bench can matter more than the volume in the bottle.

CAS number
104-55-2
Form
Liquid
Storage class
General
Signal word
Warning
Usual EWC code
16 05 06*
  • 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 general 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

Keep the bottle in a dry, labelled, well organised store and date it on arrival. A sensitiser deserves tidy handling: clean-necked bottles are safer to pick up than ones with liquid dried round the cap, so check the neck as part of every stock round. Keep the cap tight and the bottle away from light and heat. Store it apart from food grade supplies, which matters in a school where a food technology room sits next door. If an old bottle is sticky on the outside, avoid contact with the residue. Do not move a leaking or damaged bottle before specialist assessment.

How to tell it has deteriorated

Freshly received cinnamaldehyde is a clear pale yellow liquid, so what does not look normal is a darker colour, a thicker or sticky consistency, or solid material at the neck or on the cap thread. The liquid reacts slowly with air, and the product can leave residue that glues the cap on. A sticky film on the outside of the bottle means liquid has crept past the seal, and this is a skin contact risk because of the allergic reaction hazard. Also check for a faded label, a lower level than expected, cracked glass and an unknown receipt date. Treat a thick or crusted bottle as aged stock.

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 non-regulated or low hazard laboratory pack with compatible chemicals.

Waste code 16 05 06* is the usual description for a laboratory holder, and 16 05 08* applies when it is a discarded organic chemical outside a pack. Tell the collector if a bottle is sticky on the outside or has a crusted cap, because staff need to know about a skin sensitiser before they pick it up. Also record size, fill and the exact label name. It leaves in a lab pack with compatible organic liquids and a registered carrier takes it to a permitted facility. It must not be washed into a sink or put in the ordinary bin, and a leaking bottle is never cleaned up by technicians.

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

The code depends on where the waste came from and what it is mixed with. Use the waste code finder to see why.

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

  • H312 Harmful in contact with skin.
  • H315 Causes skin irritation.
  • H317 May cause an allergic skin reaction.
  • H319 Causes serious eye irritation.
Precautionary statements
  • P261 Avoid breathing dust, fume, gas, mist, vapours or spray.
  • P272 Contaminated work clothing should not be allowed out of the workplace.
  • P280 Wear protective gloves, protective clothing, eye protection and face protection.
  • P302+P352 IF ON SKIN: Wash with plenty of water.
  • P321 Specific treatment (see supplemental first aid instruction on this label).
  • P333+P317 If skin irritation or rash occurs: Get medical help.
  • P362+P364 Take off contaminated clothing. And wash it before reuse.
  • P501 Dispose of contents and container in accordance with local, regional, national and international regulations.
  • P264 Wash hands and exposed skin thoroughly after handling.
  • P264+P265 Wash hands and exposed skin thoroughly after handling. Do not touch eyes.
  • P305+P351+P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
  • P317 Get medical help.
  • P332+P317 If skin irritation occurs: Get medical help.
  • P337+P317 If eye irritation persists: Get medical help.

Substance as classified, dilutions may differ.

Questions

Why is our cinnamaldehyde bottle sticky on the outside?

Liquid has probably crept past the cap and dried. Because it may cause an allergic skin reaction, avoid contact with the residue and do not wipe it. If the bottle is leaking or its seal has failed, leave it where it stands and arrange specialist assessment before movement. Declare it as leaking stock for collection.

Is a darker cinnamaldehyde bottle unsafe to use?

Darker or thicker liquid means it has aged and changed. Hazards still apply, including skin sensitisation. Stop using it, label it as aged stock and include it on your waste list.

Does cinnamaldehyde need any special storage cabinet?

It is general stock. A dry, labelled store away from food supplies is the guidance, with extra care over cap and neck cleanliness because of the allergic skin hazard.

What do we tell a collector about a crusted cap?

Say that the cap is crusted or stuck and that liquid has dried around the neck. Do not try to free it. The collector can then handle the bottle with the right gloves and pack it upright.

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 C9H8O. EC number 203-213-9.

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