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Cobalt-free indicating silica gel is a colour-changing silica gel whose indicator is not cobalt chloride. Blue indicating silica gel is coloured with cobalt(II) chloride (CAS 7646-79-9), which shifts from blue to pink as it takes up water — but cobalt dichloride is classified under EU CLP for carcinogenicity and toxicity for reproduction and is listed on the REACH Candidate List, so an increasing share of EU-facing buyers now specify a cobalt-free alternative. A cobalt-free gel changes colour the same way in use — typically from orange toward green, or from orange toward colourless — giving the same "this pack has taken on moisture" signal without the cobalt.
The blue colour in classic indicating silica gel comes from cobalt chloride. That single ingredient is the whole reason cobalt-free gel exists, and the reason is regulatory rather than cosmetic:
None of this makes the gel dangerous in normal sealed use — it is inert and stays inside the sachet. The pressure is about classification, documentation and reputational risk, which is why "cobalt-free" has moved from a niche request to a standard line item on many enquiries.
A cobalt-free indicating gel uses an indicator that is not cobalt chloride, dyed onto the same kind of narrow-pore base gel. In use it behaves like the blue gel: dry, it is one colour; as it adsorbs moisture it changes, and the change reverses when the gel is dried again. The common colour schemes are:
Either way, the practical instruction is the same as for blue gel: regenerate or replace once roughly two thirds of the gel has changed colour. Because the change is reversible, an indicating gel tells you the state of the pack, not the history of it — for a hard record, pair it with a humidity indicator card.
| Property | Blue indicating gel | Cobalt-free indicating gel |
|---|---|---|
| Indicator | Cobalt(II) chloride, CAS 7646-79-9 | Non-cobalt indicator dye or salt |
| Hazard status of the indicator | REACH Candidate List (Art. 57a, 57c); CLP-classified | Cobalt-free; check the specific declaration for the grade |
| Typical colour change | Blue to pink | Orange to green (or orange toward colourless) |
| Base gel | Narrow pore (Type A-style) base | Narrow pore (Type A-style) base |
| Pore diameter of the base | ≈ 20–40 Å | ≈ 20–40 Å |
| Equilibrium capacity | ≈ 20–35% of own weight | ≈ 20–35% of own weight |
| Regeneration limit | ≈ 120 °C, or the indicator is destroyed | Keep low, by the grade's stated limit |
Both products sit on a narrow-pore base with a specific surface area of the order of 600 m²/g, low chloride and iron (≤ 0.02% each in reagent grades) and a pH near neutral, so the cobalt-free version is not a downgrade in performance — the difference is in the indicator, not the silica.
A cobalt-free claim is worth only as much as the paperwork behind it. For EU-facing packaging, the two document sets most often asked for are a REACH statement (Regulation (EC) No 1907/2006, confirming no SVHC above the threshold) and a heavy-metals test against the PPWR limit under Regulation (EU) 2025/40. Our PPWR heavy metals page explains the limit and what a usable report looks like; the general field list is in reading a desiccant TDS.
Where a standard or regulation is named, the number is given:
Written by the VEN Desiccant export team from supplier data sheets and from the published EU chemical and packaging rules our buyers cite. Drafting was AI-assisted; the classifications, CAS number and regulation numbers were checked against those published sources and edited by our team before publication. We publish it to help buyers ask the right compliance questions, not to rank for a keyword. Confirm the exact declaration and test report for the grade and the market you are shipping to.
Last checked: 11 October 2026.
Tell us the form, weight, colour change and destination — we will send the grade, the declaration and a quotation.
