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Chemical collection and stock control for UK schools, universities and hospitals

Nuclear fast red (CAS 6409-77-4): storage and disposal

Pink-red nuclei against a pale background are the job of nuclear fast red, a counterstain used in university, pathology and histology labs and held as powder. It is classified as irritating to skin, eyes and the respiratory tract, so dust from the jar is the practical hazard. Most holders have a single jar, which makes its condition and record the whole of the description given to a collector.

CAS number
6409-77-4
Form
Solid
Storage class
General
Signal word
Warning
Usual EWC code
16 05 06*
  • Harmful or irritant pictogramHarmful or irritant

What to do this week

  1. Check the label is readable and write down the opened date if it is not already there.
  2. Check it is stored as general stock and apart from the items listed under "Do not store with".
  3. 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

Dust is what makes this a shelf matter: the powder is irritating to skin, eyes and airways, so a loose cap or dusty thread is a condition to report rather than disturb during preparation for collection. Keep it in a closed, labelled jar in a dry general store, with a date of receipt, and open it only where there is ventilation. A tray beneath the jar will catch powder shed from the thread. Keep it apart from the other red counterstains, such as safranin or eosin, since a pink-red powder in a plain jar is easy to confuse once a label has rubbed off.

How to tell it has deteriorated

A practical check is to hold the jar up and look at the thread and shoulder. Pink-red dust there means the cap has been closing on powder, and a stain on the label or shelf means it has escaped. Sound powder is dry and loose. If it has clumped, turned damp or formed a hard cake, moisture has entered. This dye gives no specific sign of age, so it gives few visual clues beyond these, and the paperwork has to carry the evidence: no date of receipt, a faded label or a record that no longer matches. An unlabelled red jar should be left sealed and listed as unknown.

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.

Hospital pathology and other human healthcare services clearing this stock use 18 01 06*, and a university or school store uses 16 05 06*, so the setting comes first on the request. Say it is a powder, give the jar size and mention dust on the outside or a damaged lid. Because it irritates skin, eyes and airways, a jar with spilled powder is bagged on its own so the carrier can handle it. It is never emptied into a sink or general waste and nobody should try to clean or treat it first. Leave it sealed and upright until the collection.

Waste codes and transport details for Nuclear fast red
EWC code, laboratory chemicals16 05 06*
Discarded organic chemical, not a laboratory pack16 05 08*
Human healthcare setting18 01 06*
Hazardous wasteYes

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.
  • P271 Use only outdoors or in a well-ventilated area.
  • P280 Wear protective gloves, protective clothing, eye protection and face protection.
  • 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).
  • 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

Why does nuclear fast red need ventilation when opening?

Its classification includes irritation of the airways as well as skin and eyes, so the powder should not be allowed to become airborne. Avoid creating airborne dust. If the cap thread is contaminated, leave the deposit undisturbed and record the condition for collection.

Can it be confused with other red stains?

Yes. Many pink and red powders look alike once a label has rubbed off. Rely on the label and stock record, and list an unidentified red jar as unknown stock without opening it.

How do we tell if an old jar has deteriorated?

This dye gives few visible signs of age. Check that the powder is dry and loose, the cap is clean and the label and date are readable. A caked, damp or undated jar should be listed for collection.

What code does a hospital pathology lab use?

Human healthcare settings use 18 01 06* for this powder, while school, college or university stores use 16 05 06*. State the setting when you request the collection.

Guidance only. Check your own risk assessment and your supplier's safety data sheet.

Hazard data source: PubChem GHS Classification, retrieved 31 Oct 2026. Formula C14H8NNaO7S. EC number 229-088-0.

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