Coin cell battery safety: what the OPSS review found

ReportedPublished 21 February 20264 min read

Two silver coin cells sealed inside a child-resistant blister card lying on a pale kitchen table beside a small screwdriver

Coin cell battery safety is not an abstract question for anyone who owns a finding tag: the CR2032 inside it is exactly the class of battery that safety bodies have spent five years working on. On 28 November 2025 the Office for Product Safety and Standards published a review by its Evaluation and Research Team of the technologies being developed to reduce the risk, and it is a useful document for owners as well as manufacturers. This piece summarises what it examined, what the UK standard already requires, and what follows practically for a household with a tag in it.

What the OPSS review examined

The review is a survey of emerging technical approaches rather than a set of new rules. According to the OPSS blog post of 28 November 2025, its scientists grouped the technologies into three categories.

Approach	What it covers	Status per the review
Bitterant and diagnostic methods	Bitter coatings intended to deter swallowing, plus dyes and radiographic markers that make an ingested cell easier to identify	More research outside the laboratory is needed
Reactive technologies	Chemical casings, pressure-sensitive mechanisms and fuses that activate on contact with bodily fluids, to limit tissue damage	An active area of development
Safe-by-design approaches	Smaller cells, reduced toxic materials, lower energy capacity and alternative power sources	Alternative power sources are unlikely to remove the need for the other safeguards

That final observation is the one worth dwelling on. The review's position is that no substitution is currently in prospect which would make coin cells unnecessary in small devices, so the safety work has to be done on the cells and the products that hold them rather than by designing them out.

What the UK standard already requires

The relevant document is PAS 7055:2021, published by BSI on 30 April 2021 with sponsorship from OPSS, and described by the government at the time as the first standard to address the safety issues posed by button and coin batteries.

It applies to cells up to 32 mm in diameter — which comfortably includes the CR2032, at 20 mm across and 3.2 mm thick — and covers labelling, instructions and packaging, the alignment of safety and health warnings, how the batteries are merchandised in shops, and safe disposal.

Two qualifications matter. First, the standard is a Publicly Available Specification, not a statutory instrument: a responsible business follows it, and there is no criminal offence in ignoring it as such. Second, general safety duties still apply to any consumer product sold in the UK regardless, so a product presenting an unnecessary risk is a problem for its seller whatever any voluntary standard says.

Why coin cells are treated differently from other batteries

Because of what happens if one is swallowed. A cell lodged in soft tissue creates a current that generates hydroxide at one pole, and the resulting chemical burn develops quickly rather than over days. This is the reason the safety literature is so insistent about immediate medical attention rather than waiting to see, and why the packaging requirements in the standard concentrate on making a cell difficult for a small child to reach in the first place.

The practical risk profile of a finding tag follows from that. The cell is enclosed behind a cover that requires a deliberate twist, which is appropriate. The risk moment is not the tag in normal use; it is the loose replacement cell on a kitchen table, and the moments during a battery change when the old cell is out and not yet in a bin.

What this means if you own a tag

Buy replacement cells in child-resistant packaging and leave them in it until the moment of use. The standard exists partly to make sure you can.
Change the cell away from children, and put the old one straight into a container they cannot open rather than on a worktop.
Do not keep dead cells in a drawer. A depleted coin cell retains enough charge to cause injury.
Take them back to a shop. Under the Waste Batteries and Accumulators Regulations 2009, UK retailers selling more than 32 kg of portable batteries a year must provide a collection point; most large supermarkets have a box near the entrance.
Treat any suspected ingestion as an emergency and seek immediate medical help rather than monitoring at home.

How BlueTag is built around this

BlueTag takes a single CR2032 behind a cover that has to be twisted deliberately to release — not a slide, not a push-fit, and not something a child manages absent-mindedly. The cell runs for up to two years, so the moment of exposure described above happens roughly twice in the life of a tag rather than every few months.

We supply no loose spare cells in the box, deliberately: what arrives is two BlueTag trackers with their cells fitted, two key rings and a setup sheet. When a replacement is needed, buying one in proper retail packaging from a supermarket is both cheaper and safer than a bare cell rattling around in a padded envelope. Our practical guide to battery life and changing the cell covers the swap itself.

Everything else about the tag is unchanged by any of this: IP67 sealing, up to 60 m / 200 ft of Bluetooth link with the Apple Find My network beyond it, iPhone and iPad on iOS 14.5 or later, no Android support, no Ultra Wideband. Two tags in a box, free UK delivery, under £15 — see the specification.

Sources

From the desk of Bluetooth Tracker Last revised 21 February 2026

Related notes

← All workbench notes