Chemical disposal of Sudan 3

Chemical disposal of Sudan 3: What are the requirements for disposal of Sudan 3?

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Publication Date: 01 November 2018
Asked By: Anonymous
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Chemical disposal of Sudan 3

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Sudan III is

  • a biological dye that is used to test for fats, oils and waxes
  • not soluble in water and is typically made up in a 70% solution of ethanol (or methylated spirits)
  • classified as non-hazardous, however when in 70% ethanol is classified as hazardous due to the flammability of the ethanol.

Dyes, indicators and stains

It is important to be aware that dyes, indicators and stains may not be very pure, particularly in very old samples. Through their manufacture, they may contain hazardous impurities. Some dyes may be metabolised in the body to substances which are harmful. Sometimes there is limited or incomplete information regarding the hazards. Therefore, great care should be exercised when handling all dyes, indicators and stains.

Students should only use dilute solutions of dyes, indicators and stains; where the hazard is greatly reduced.

Therefore, although Sudan III is classified as non-hazardous, it should be handled with great care.

Disposal of Sudan III

Disposal of Sudan III depends upon whether it is in solid form or in solution and the quantity involved.

  • A small quantity of Sudan III in dilute (up to 0.5%) solution (say <20ml) used in science classes can be washed to waste
  • Larger quantities of Sudan III in solution should be saved for disposal by a licenced chemical waste contractor
  • In solid form, care should be taken to avoid generating or inhaling dust and to avoid skin contact. It should be saved for disposal by a licenced chemical waste contractor


CLEAPSS. 2016. CLEAPSS Hazcards, Number 32 Dyes, indicators and stains, CLEAPSS website, (Member login required)

CLEAPSS. 2013. CLEAPSS Student Safety Sheets, Number 70 Dyes and indicators, CLEAPSS website,

NSW Department of Education and Training. 1999. ‘Chemical Safety in Schools (CSIS)’ resource package. Sydney: NSW

Scharlau. 2013. Sudan III, C.I. 26100, for microscopy, Safety Data Sheet, Chem-Supply website, (Updated December 2019)

Chem-Supply. 2019. Sudan 3, Safety Data Sheet, Chem-supply website,

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