Uranyl acetate (CAS 541-09-3): storage and disposal
Uranyl acetate is a radioactive and toxic uranium salt, used mainly as a stain in electron microscopy suites in universities and histology departments. It comes as yellow crystals, often the dihydrate, or as made solutions, and contaminated grids and tips count too. It is fatal if swallowed or inhaled. Radioactive substances rules decide how it is kept and where it goes, so your Radiation Protection Adviser leads on it.
- CAS number
- 541-09-3
- Form
- Solid
- Storage class
- Toxic
- Signal word
- Danger
Acute toxicity
Serious health hazard
Hazardous to the environment
This chemical is a manual enquiry
This is radioactive. Radioactive sources need their own permits and a specialist route, so we look at each one individually.
Uranium compound, radioactive.
It cannot be priced through a form. Please do not open or move it. Call us or send an enquiry and we will talk through the safe next step, which is often a store assessment.
What to do this week
- Leave it where it is. If it looks old, crystalline or damaged, do not open or move it and keep people away from the shelf.
- Write down the label wording, the rough age and where it is stored, from a safe distance.
- Send us those details, and a photo if you can take one without touching it.
Safe storage in a school or lab
Check that the amount on the shelf agrees with the record of holding, including any stain solution in the fridge and the small bottles of crystals. Discrepancies are common on a bench where several users weigh out small amounts. Keep it where it is, labelled, in a locked and designated radioactive store, away from food and drink. Stain solutions are normally kept dark because they are sensitive to light, so a foil wrapped bottle is a familiar sight, and that wrapping can hide the label. Used grids, tips and wipes count as well, and they need a marked holding container in the same store. The crystals are fatal if inhaled as dust, so nobody should disturb an old bottle.
How to tell it has deteriorated
A foil wrapped bottle with a handwritten date is typically what you see first in an electron microscopy suite. Solutions that have aged or been exposed to light can throw a fine yellow deposit on the base and walls, and a working stain in that state is often just replaced, leaving the old one on the shelf. Crystals should be bright yellow, and caking or crusting around the cap suggests the bottle has been opened often. A faint vinegar smell can come from the acetate. Age does not reduce its radioactive status in any practical sense, so an old bottle is still within the rules. Do not filter or rescue a stain with deposit, and report anything that has leaked.
How it must be disposed of
This does not go through our standard collection route. It is arranged by manual enquiry, and never goes down the drain or into general waste.
It leaves the site through your Radiation Protection Adviser or Radioactive Waste Adviser, because it is radioactive material and sits outside a chemical collection. Your institution's permit, and the record of holding, determine who can take it. We do not quote for it online. An enquiry can be sent if your adviser wants help working out what is held, and a store assessment is recommended. Used grids, tips and old stain all need to be counted, so list them by type and approximate number. Never tip old stain or rinse a used grid into a sink, and do not put them in a general waste bin. Keep everything where it is until your adviser has responded.
| Hazardous waste | Yes |
|---|
No List of Waste code is given here. The waste is outside the chemical collection stream and is assessed by manual enquiry.
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: dihydrate, electron microscopy stain.
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
- H300 Fatal if swallowed.
- H330 Fatal if inhaled.
- H373 May cause damage to organs through prolonged or repeated exposure.
- H411 Toxic to aquatic life with long lasting effects.
Precautionary statements
- P260 Do not breathe dust, fume, gas, mist, vapours or spray.
- P264 Wash hands and exposed skin thoroughly after handling.
- P270 Do not eat, drink or smoke when using this product.
- P271 Use only outdoors or in a well-ventilated area.
- P273 Avoid release to the environment.
- P284 In case of inadequate ventilation wear respiratory protection.
- P301+P316 IF SWALLOWED: Get emergency medical help immediately.
- P304+P340 IF INHALED: Remove person to fresh air and keep comfortable for breathing.
- P316 Get emergency medical help immediately.
- P319 Get medical help if you feel unwell.
- P320 Specific treatment is urgent (see supplemental first aid instruction on this label).
- P321 Specific treatment (see supplemental first aid instruction on this label).
- P330 Rinse mouth.
- P391 Collect spillage.
- 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
Do used grids and pipette tips really count as radioactive waste?
Yes, they do. Contaminated grids and tips are treated as part of the uranyl acetate holding, however small the amount on each. Keep them in a marked container in the designated store, and ask your Radiation Protection Adviser how they should be recorded. They should never go out with general lab waste.
How should we handle a stain bottle left in the suite by a former researcher?
Leave it in place and tell the Radiation Protection Adviser. It needs to go on the record of holding, with the date it was found and any label wording. Avoid opening it to check the contents, and do not combine it with your current stain.
Our stain has a yellow deposit in it. Does that change how it is dealt with?
It does not change the route. Deposit usually means the solution has aged or seen light, and it remains radioactive material with a fatal if swallowed classification. Keep the bottle upright and capped where it is, note what you see and include it in your report to your adviser.