Phenylhydrazine (CAS 100-63-0): storage and disposal
Neat phenylhydrazine is a liquid that darkens in air, and it sits in a few college and university stores left over from sugar and carbonyl practicals. It is toxic through the skin, may cause cancer and is suspected of causing genetic defects. Most bottles are old and part used, so the choice is almost never about using the stock. It is about holding it safely until someone collects it.
- CAS number
- 100-63-0
- Form
- Liquid
- Storage class
- Toxic
- Signal word
- Danger
- Usual EWC code
- 16 05 06*
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
Skin absorption decides the shelf. Phenylhydrazine is toxic in contact with skin, may cause cancer and causes damage to organs through repeated exposure, so it belongs in a locked toxic cabinet with a stock record, well away from food and drink areas. Keep it separate from acids and oxidisers, because toxic stock beside them can release hazardous vapours if a bottle fails. Stand the bottle in a tray so a weeping cap shows up as a stain in the tray and not on the shelf. In a college store this is often a bottle bought for a single practical and then forgotten. Find the label date and the last person to sign it out.
How to tell it has deteriorated
Check the bottle and label first: staining around the cap, a sticky neck, a faded or splashed label. Then look at the liquid through the glass. Fresh phenylhydrazine is pale, and it darkens with air, so a bottle gone dark has taken in air through a poor seal or has been opened many times. Darkening is the chemical-specific sign here, and it says the stock is old, not that it can be handled casually. Do not unscrew an old bottle to inspect it. Record the colour, the label state and the cap condition for the collection description, and keep the bottle in its tray until then.
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.
It must not be poured away and nobody may try to neutralise what is left, since it is toxic through the skin, may cause cancer and is very toxic to aquatic life. It leaves as legacy hazardous stock by specialist collection, in a lab pack under UN 2572, grouped with other toxic organic liquids and kept from oxidisers and acids. Waste code 16 05 06* fits a laboratory chemical, and 16 05 08* applies to discarded organic chemical outside a lab pack. Keep the bottle upright in its tray, write down the label wording and colour, and tell the collector if it has darkened. Neither a drain nor general waste is an option.
| 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.
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: 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
- H301 Toxic if swallowed.
- H311 Toxic in contact with skin.
- H315 Causes skin irritation.
- H317 May cause an allergic skin reaction.
- H319 Causes serious eye irritation.
- H331 Toxic if inhaled.
- H341 Suspected of causing genetic defects.
- H350 May cause cancer.
- H372 Causes damage to organs through prolonged or repeated exposure.
- H400 Very toxic to aquatic life.
Precautionary statements
- P203 Obtain, read and follow all safety instructions before use.
- P260 Do not breathe dust, fume, gas, mist, vapours or spray.
- P261 Avoid breathing dust, fume, gas, mist, vapours or spray.
- P262 Do not get in eyes, on skin, or on clothing.
- 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.
- P272 Contaminated work clothing should not be allowed out of the workplace.
- 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.
- 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.
- P316 Get emergency medical help immediately.
- P318 If exposed or concerned, get medical advice.
- 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.
- P333+P317 If skin irritation or rash occurs: Get medical help.
- P337+P317 If eye irritation persists: Get medical help.
- P361+P364 Take off immediately all contaminated clothing. And wash it before reuse.
- P362+P364 Take off contaminated clothing. And wash it before reuse.
- 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
Is a dark bottle of phenylhydrazine more dangerous than a pale one?
Darkening shows air has reached the liquid, which means the stock is old and the seal may be poor. The classification itself is the same, and it is already toxic and may cause cancer. Treat a dark bottle as old legacy stock, leave it closed and have it collected.
Can we keep phenylhydrazine in the same cabinet as organic solvents?
No. It is classified as toxic, so it goes in a locked toxic cabinet with a stock record. Putting it beside acids or oxidisers is a particular concern, and a cabinet shared with solvents usually holds both. Move it to its own space and tray.
What do we write on the stock record for an old bottle?
Record the name, the label wording, the approximate volume left, the colour you can see through the glass and the condition of the cap. Add the date of last known use if anyone remembers it. That gives the collection an accurate description without anyone opening the bottle.