Hoechst 33342 (CAS 875756-97-1): storage and disposal
Live cells take up Hoechst 33342, which is why imaging and flow cytometry groups in university and pathology labs keep the trihydrochloride as a powder in the cupboard. It is harmful if swallowed, irritates skin and airways, and is suspected of causing genetic defects. Because it is bought in small vials, the real storage question is usually how many nearly empty vials are scattered around the lab and who has a record of them.
- CAS number
- 875756-97-1
- Form
- Solid
- Storage class
- Toxic
- Signal word
- Warning
- Usual EWC code, laboratory stock
- 16 05 06*
Harmful or irritant
Serious health hazard
What to do this week
- Without moving anything that looks damaged, 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 anything listed under "Do not store with" on this page. If nothing is listed, that does not prove it is safe with everything.
- If you no longer need it, add it to your disposal list so it can be included in a collection.
Safe storage in a school or lab
Keep it in controlled storage and segregate it according to the safety data sheet for the specified Hoechst 33342 product. A locked cabinet with a stock record suits a substance suspected of causing genetic defects, and the record is what lets a lab account for small vials that move between benches. Keep the vial closed in its box and date the label. If powder is present on the neck, report the contamination rather than disturbing it. Handle it with gloves and open it only with ventilation, as the dust irritates the airways. Small vials left in a drawer or in a bench rack are the likeliest to lose their labels.
How to tell it has deteriorated
Few visible signs of age can be relied on for this stain, so use the container as evidence. The powder should be dry and loose. Caking, a damp look or a hard crust means moisture has entered. A stain around the cap, a vial with a cracked neck or a label that has rubbed off or gone yellow are all reasons for concern. The most common problem is the vial that has simply lost its record: no date of receipt, no entry in the stock book, and a label that no longer says who owned it. A vial like that is treated as unknown, left sealed and listed, not opened for a closer look.
How it is disposed of
We arrange this by specialist collection. We do not publish a drain or general waste route for any chemical. It is normally packed in a toxic laboratory pack with compatible chemicals.
Never empty a vial into a sink or put it into general waste, and do not try to rinse or treat it first. List every vial on its own line or as a counted group of identical vials, with the approximate amount left and the state of the label, so the carrier can plan the packing. A university or laboratory store would normally use 16 05 06*, and a human healthcare pathology service clearing stock would normally use 18 01 06*. Because it is suspected of causing genetic defects, a vial with powder on the outside is bagged on its own. Keep every vial sealed and upright until collection.
| Usual EWC code, laboratory stock | 16 05 06* |
|---|---|
| Discarded organic chemical, not a laboratory pack | 16 05 08* |
| Human healthcare setting | 18 01 06* |
| Usually classed as hazardous waste | Yes |
The code depends on where the waste came from and what it contains, and classifying it is the producer's duty. 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
Usually held as: trihydrochloride.
Tell us the container size and how many you hold. An estimate is enough to start with, and some items cannot be priced until someone has looked at them.
Where it is commonly held
Hazard statements
- H302 Harmful if swallowed.
- H315 Causes skin irritation.
- H335 May cause respiratory irritation.
- 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.
- 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.
- 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.
- 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
How do we list a drawer of tiny Hoechst vials?
Count them, group identical vials together and note the approximate amount in each and whether labels are legible. Keep them sealed in a labelled box, with any damaged vial bagged separately.
Why is Hoechst 33342 kept apart from acids and oxidisers?
Oxidisers should be segregated where they are incompatible with the organic dye. There is no established general requirement to keep Hoechst 33342 apart from every acid, and suspected mutagenicity does not itself imply a harmful-vapour reaction. Follow the product safety data sheet for the specific storage requirements.
What should we do with empty or nearly empty vials?
Treat a vial that has held the powder as chemical stock until the collector advises otherwise. Do not rinse it. List it with a note that it is empty or nearly empty.
Which waste code do we use?
A university or laboratory store would normally use 16 05 06*, while a human healthcare pathology service would normally use 18 01 06*. Give the setting when you request the collection.
