Borax (disodium tetraborate decahydrate)
CAS 1303-96-4 · EC 603-411-9
Also known as sodium borate decahydrate, disodium tetraborate decahydrate
Most-notified self-classification for the decahydrate record is "Not classified" (66.52%), contrary to the harmonised entry; the harmonised classification takes precedence.
Handle chemistry safely
Wear gloves and eye protection, work with good ventilation, and read the supplier’s safety data sheet before use. Hazard information here is a summary, not a replacement for it. Dispose of all photographic chemistry correctly, in line with local laws and your local authority’s guidance. Never mix waste solutions, and check the supplier’s safety data sheet before disposing of anything.
Hazards
Official EU classification (harmonised under CLP Annex VI).
Signal word: Danger
Serious health hazard
- H360FD May damage fertility. May damage the unborn child.
UK and EU rules
- CLP Annex VI Repr. 1B (H360FD) – harmonised entry 005-011-00-4 (ATP20)
- REACH Candidate List (SVHC): listed by ECHA as "Disodium tetraborate, anhydrous" (CAS 1330-43-4), included 18-Jun-2010 for toxicity to reproduction
Photographic uses
- mild accelerator (D-76, D-96)
Used in: Kodak D-76, Kodak D-96
Sources
- ECHA CHEM substance record: Disodium tetraborate decahydrate (100.129.152)
- ECHA CHEM – C&L Inventory (harmonised CLP Annex VI and notified classifications) and legal obligations (chem.echa.europa.eu APIs: /api-cnl-inventory/harmonized|industry, /api-obligation-substance/v1)
- REACH Annex XVII entries 28–30 (CMR substances – supply to general public) (Annex XVII entries 28, 29, 30; latest consolidated act CELEX 32025R1731)
Checked October 2026.