Glyoxal (CAS 107-22-2): storage and disposal
Glyoxal is a small dialdehyde, held in university, pathology and histology stores as a 40% aqueous solution. It is harmful if swallowed or inhaled, irritates skin and eyes, may cause an allergic skin reaction and is suspected of causing genetic defects. Where a bottle holds a more dilute solution it may be less hazardous than the pure substance, so the label strength matters when the waste is described.
- CAS number
- 107-22-2
- Form
- Solution
- Storage class
- Toxic
- Signal word
- Warning
- Usual EWC code
- 16 05 06*
Harmful or irritant
Serious health hazard
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 toxic 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
Keep it away from oxidisers and from acids. Oxidising stock and this class of material are stored apart because a reaction could release hazardous vapours, and acid contact is a separate concern in the same cabinet. Use a locked cabinet with a stock record, away from food and drink areas, and keep the cap tight so that water does not leave the solution. In a histology or pathology laboratory, bottles are often split into small working volumes, so label every one with the strength and the date. A sensitiser should be moved with gloves on, and a bottle with a wet neck is set in a tray before it is lifted.
How to tell it has deteriorated
Solution that is losing water at the cap tends to leave a white, sticky or crystalline deposit on the thread, and that deposit can glue a cap on. A bottle that has gone cloudy, thick or has a gel-like layer has changed from the clear liquid it started as. Check the level against the stock record, since a poorly closed bottle loses volume, and look for faded labels, a damp or stained outside and cracked plastic. Any bottle with an unknown strength, or without a receipt date, is treated as unknown stock. Do not try to free a seized cap with force, because the wet residue on the thread is a sensitiser.
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 toxic laboratory pack with compatible chemicals.
The collection leaves by specialist route with the bottle declared at its labelled strength, since a 40% solution and a diluted working bottle are not described in the same way. Waste code 16 05 06* is the usual description, with 18 01 06* in a human healthcare laboratory and 16 05 08* for a discarded organic chemical outside a pack. Write down the volume, the container type and whether a deposit has formed. It is suspected of causing genetic defects, so it is never poured away, never put in the bin and never evaporated, and nobody should try to clean up a leak with a neutralising step.
| 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 |
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
- 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 we collect
Usually held as: 40%.
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
- H302 Harmful if swallowed.
- H315 Causes skin irritation.
- H317 May cause an allergic skin reaction.
- H319 Causes serious eye irritation.
- H332 Harmful if inhaled.
- H341 Suspected of causing genetic defects.
Precautionary statements
- P203 Obtain, read and follow all safety instructions before use.
- P261 Avoid breathing dust, fume, gas, mist, vapours or spray.
- P264 Wash hands and exposed skin thoroughly after handling.
- P264+P265 Wash hands and exposed skin thoroughly after handling. Do not touch eyes.
- P271 Use only outdoors or in a well-ventilated area.
- 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.
- 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.
- P317 Get medical help.
- P318 If exposed or concerned, get medical advice.
- P321 Specific treatment (see supplemental first aid instruction on this label).
- P332+P317 If skin irritation occurs: Get medical help.
- P333+P317 If skin irritation or rash occurs: Get medical help.
- P337+P317 If eye irritation persists: Get medical help.
- P362+P364 Take off contaminated clothing. And wash it before reuse.
- P405 Store locked up.
- P501 Dispose of contents and container in accordance with local, regional, national and international regulations.
- P233 Keep container tightly closed.
- P260 Do not breathe dust, fume, gas, mist, vapours or spray.
- P270 Do not eat, drink or smoke when using this product.
- P284 In case of inadequate ventilation wear respiratory protection.
- P301+P317 IF SWALLOWED: Get medical help.
- P319 Get medical help if you feel unwell.
- P330 Rinse mouth.
- P342+P316 If experiencing respiratory symptoms: Get emergency medical help immediately.
- P403 Store in a well-ventilated place.
- P403+P233 Store in a well-ventilated place. Keep container tightly closed.
Substance as classified, dilutions may differ.
Questions
Our glyoxal bottle has a white deposit round the cap. Is that a problem?
It usually means water has left the solution at the thread. The deposit can seal the cap, and the residue may sensitise skin. Wear gloves, keep the bottle upright in a tray, do not force the cap, and declare it as aged stock.
Can we dilute old glyoxal before sending it for collection?
No. Diluting waste changes what is in the bottle and creates more liquid to handle. Declare it at the strength on the label, say it is waste, and leave it in its original container.
Where should glyoxal sit in a histology store?
In a locked cabinet with a stock record, away from food and drink areas, from acids and from oxidisers. Keep small decanted bottles in the same cabinet and label them with the strength and the date.
Which waste code applies in a hospital pathology lab?
A human healthcare setting can be described under 18 01 06*, while a university store uses 16 05 06*. Tell the collector what kind of laboratory you are and they will confirm the description.
