Phenylmercuric acetate (CAS 62-38-4): storage and disposal
Phenylmercuric acetate is an organic mercury compound once used as a preservative, now found as legacy stock in university stores and pharmacy cupboards. It is toxic if swallowed, causes severe skin burns and eye damage, damages organs through repeated exposure and is very toxic to aquatic life. It remains a mercury waste however old it is, so identifying it correctly matters more than anything its appearance can tell you.
- CAS number
- 62-38-4
- Form
- Solid
- Storage class
- Toxic
- Signal word
- Danger
- Usual EWC code
- 16 05 06*
Corrosive
Acute toxicity
Serious health hazard
Hazardous to the environment
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
Acids and oxidisers are the two classes it must be kept from, because toxic stock is held apart from both to avoid a reaction or a release of toxic gas. In practice that means a locked cabinet with a stock record, well away from food and drink areas, and a resistant tray because it causes severe burns as well as being toxic. In a pharmacy, the risk is a small bottle of old preservative left among raw materials and mistaken for an ordinary excipient, so it needs moving to controlled storage and an added label saying it contains mercury. University holders are more likely to find it in a store of inherited organometallics, where it should keep a clear label and a separate place from the oxidising mercury salts.
How to tell it has deteriorated
A white or off-white crystalline solid is what sound stock looks like, and old stock often looks exactly the same. It gives few visible signs of ageing, which is why the container deserves more attention than the powder. A brittle cap, staining around the neck, a failed seal or a faded preservative label are the things to write down. Grey or dark discolouration is not expected, and a bottle showing it should be recorded as of uncertain condition. Pharmacy stock may carry a label from an old supplier with little to show it is mercury based, and that gap is the more dangerous fault. A clean appearance gives no comfort about the contents, so the bottle stays closed.
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.
For a pharmacy or other human healthcare holder, 18 01 06* is the code that fits, and a university sending it in a lab pack uses 16 05 06*. Both carry the asterisk that marks hazardous waste. Whichever applies, list it by its full name and state that it is organic mercury, since that sets the grouping and keeps it apart from inorganic oxidising salts. Say whether it is solid or a made-up preservative solution, and how much is left. Specialist collection is the single route. Do not put it in a sink, drain, general waste bin or skip, and do not try to treat it beforehand. Bottles from an old preservative stock often turn up in several sizes, so count them all.
| 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: legacy preservative.
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
- H301 Toxic if swallowed.
- H314 Causes severe skin burns and eye damage.
- H372 Causes damage to organs through prolonged or repeated exposure.
- H410 Very 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.
- P273 Avoid release to the environment.
- P280 Wear protective gloves, protective clothing, eye protection and face protection.
- P301+P316 IF SWALLOWED: Get emergency medical help immediately.
- P301+P330+P331 IF SWALLOWED: Rinse mouth. Do NOT induce vomiting.
- P302+P361+P354 IF ON SKIN: Take off immediately all contaminated clothing. Immediately rinse with water for several minutes.
- P304+P340 IF INHALED: Remove person to fresh air and keep comfortable for breathing.
- P305+P354+P338 IF IN EYES: Immediately rinse with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
- P316 Get emergency medical help immediately.
- P319 Get medical help if you feel unwell.
- P321 Specific treatment (see supplemental first aid instruction on this label).
- P330 Rinse mouth.
- P363 Wash contaminated clothing before reuse.
- P391 Collect spillage.
- 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
Should it be listed as an ordinary preservative or as a mercury compound?
As a mercury compound, with its full name. Calling it a preservative hides the hazard from anyone reading the list, and it stays a mercury waste however little remains. Add the word preservative only as extra detail if the label uses it.
Can it stay with our inherited organic reagents until collection?
Only if that store is locked, has a stock record and contains no acids or oxidisers. It causes severe burns as well as being toxic, so a resistant tray helps. A shelf of mixed unknown reagents is a poor place for it, even for a short wait.
It looks perfect after decades. Could we not simply keep it?
Looks prove little here, as the solid gives few visible signs of age. If nobody has a current use for it, it should leave as waste. Holding it adds a stock record and a locked space for a mercury compound that has no purpose on site.