Luminol (CAS 521-31-3): storage and disposal
In school and college science departments luminol is the pale powder kept for chemiluminescence demonstrations and forensic style practicals. It is classified as causing skin and serious eye irritation and may cause respiratory irritation. A jar is used a few times a year at most, so the stock tends to be old, and the question is mostly how to hold it safely until collection.
- CAS number
- 521-31-3
- Form
- Solid
- Storage class
- General
- Signal word
- Warning
- Usual EWC code
- 16 05 06*
Harmful or irritant
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 general 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
The sector that holds it first is the school prep room, where luminol often sits among demonstration chemicals, and that is where mixing up shelves does harm. Keep it away from bleach and hydrogen peroxide, which are oxidising agents, and store demonstration reagents such as metal salts separately to prevent accidental mixing. It does not need a special cabinet. A dry, labelled, well organised store with a tight cap is enough, and the jar should be dated on arrival. The classified irritation of skin, eyes and airways means the jar is best opened where dust cannot drift into the room.
How to tell it has deteriorated
Powder that was pale starts to look yellow or dull with age and light, so a jar that has changed colour is an older one. Few other visible signs belong to this chemical, so use the general checks: clumping where damp has reached the contents, a faded label, dusting around the cap and a missing receipt date. A jar that has sat in a demonstration box next to oxidising chemicals deserves a closer look at the cap and label. Record the colour, the cap condition and the date if known, and do not open a caked jar to loosen it.
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.
A school jar of luminol is usually small and old, and the record to make before asking for a collection is the label wording, the container type, the colour and the approximate quantity. It goes by specialist collection in a lab pack with other solid organic chemicals, under waste code 16 05 06*, or 16 05 08* where it is discarded organic chemical outside a lab pack. Putting the powder in a drain or general waste is not acceptable, and nobody may try to use it up or treat it first. Keep bleach and peroxide solutions away from it until it leaves.
| EWC code, laboratory chemicals | 16 05 06* |
|---|---|
| Discarded organic chemical, not a laboratory pack | 16 05 08* |
| 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.
Common quantities we collect
Usually held as: solid.
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
- H315 Causes skin irritation.
- H319 Causes serious eye irritation.
- H335 May cause respiratory irritation.
Precautionary statements
- 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.
- P270 Do not eat, drink or smoke when using this product.
- P271 Use only outdoors or in a well-ventilated area.
- P280 Wear protective gloves, protective clothing, eye protection and face protection.
- P301+P317 IF SWALLOWED: Get medical help.
- 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.
- P319 Get medical help if you feel unwell.
- P321 Specific treatment (see supplemental first aid instruction on this label).
- P330 Rinse mouth.
- P332+P317 If skin irritation occurs: Get medical help.
- P337+P317 If eye irritation persists: Get medical help.
- P362+P364 Take off contaminated clothing. And wash it before reuse.
- P403+P233 Store in a well-ventilated place. Keep container tightly closed.
- 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
What should luminol not be stored near?
Keep it apart from bleach, hydrogen peroxide and any metal salts kept for demonstrations. Luminol chemiluminescence involves oxidation under suitable conditions, with some metal ions acting as catalysts. Contact with a metal salt alone does not establish those conditions. A separate shelf or cabinet is enough, with the jar closed and labelled.
Does an old jar of luminol become dangerous?
The visible signs of age are mostly yellowing, dullness and caking, none of which makes the powder a different waste. It stays classified as an irritant to skin, eyes and airways. Leave it closed, record its condition and have it collected.
Can we use up a small quantity in a demonstration rather than dispose of it?
That is a decision for your own staff and risk assessment. If the jar is old, undated or caked, collection is simpler. We only describe the waste route. Do not tip leftover powder into a drain or general waste.
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