Chemical safety
Ethidium bromide: hazards and COSHH prompts
The classic DNA stain and mutagen — the reason many labs run a designated area and waste stream.
Always work from your own safety data sheet. Classification varies with grade, concentration and supplier. Use this page to orient yourself, then assess the task you are actually doing, at the scale you are actually doing it.
Hazard classification
- CAS
- 1239-45-8
- Formula
- C21H20BrN3
- Molecular weight
- 394.3
- Signal word
- Danger
GHS pictograms
Hazard statements
- H302Harmful if swallowed
- H330Fatal if inhaled
- H331Toxic if inhaled
- H341Suspected of causing genetic defects
Precautionary statements (18)
- P203Obtain, read and follow all safety instructions before use.
- P260Do not breathe dust, fume, gas, mist, vapours or spray.
- P261Avoid breathing dust, fume, gas, mist, vapours or spray.
- P264Wash hands thoroughly after handling.
- P270Do not eat, drink or smoke when using this product.
- P271Use only outdoors or in a well-ventilated area.
- P280Wear protective gloves, protective clothing, eye protection and face protection.
- P284P284
- P301+P317IF SWALLOWED: Get medical help.
- P304+P340IF INHALED: Remove person to fresh air and keep comfortable for breathing.
- P316Get emergency medical help immediately.
- P318If exposed or concerned, get medical advice.
- P320P320
- P321Specific treatment — see the safety data sheet.
- P330Rinse mouth.
- P403+P233Store in a well-ventilated place. Keep container tightly closed.
- P405Store locked up.
- P501Dispose of contents and container in accordance with local, regional and national regulations.
Classification data from PubChem CID 14710 , retrieved automatically and refreshed weekly. PubChem aggregates from multiple suppliers; entries can differ from the SDS for your grade.
What your COSHH assessment has to answer
Based on the hazard classes above. These are prompts, not answers — the right control depends on your task, your quantities and your room.
Because it is acutely toxic
- Which exposure route is credible for your task — inhalation, skin, or both?
- Is containment engineered (fume hood, cabinet) rather than relying on PPE?
- What is the first-aid response, and is the material for it actually at the point of use?
- Is lone working with this restricted?
Because it is a carcinogen, mutagen or reproductive hazard
- Has substitution been considered, and is the reason for not substituting recorded?
- Is exposure reduced as low as reasonably practicable, not merely below a limit?
- Are new and expectant mothers specifically considered?
- Is health surveillance or exposure monitoring expected for this work?
Others in fixatives & biological reagents
Formaldehyde solution (formalin)
The standard fixative, and a recognised carcinogen with tight workplace exposure limits.
ReadParaformaldehyde
Powder form that depolymerises to formaldehyde — heating to dissolve it is the exposure risk.
ReadPhenol
Present in many nucleic-acid extraction reagents; causes severe burns that can be painless at first.
ReadStop rebuilding this by hand
Keep Ethidium bromide — and everything else — in one inventory.
LevelSixLabs pulls GHS classification onto your chemical records automatically, then builds COSHH assessments from the substances you already hold. Explore a fully-stocked demo lab, no signup.