Are Bromine Granules Being Banned? Your Questions Answered

If you use bromine granules to look after your hot tub water, you will need to change to another form of sanitisation. A new regulatory decision means bromine granules are being phased out in Great Britain, with sales prohibited after 1 April 2027 and their use prohibited after 1 October 2027.

That sounds rather more alarming than the reason behind it. The change has not been prompted by a newly discovered health risk, and bromine itself is not being banned. Also, bromine tablets are unaffected. The problem lies with the chemical combination used in bromine granules and the withdrawal of regulatory support for it.

Our supplier has already stopped supplying bromine granules. We still have limited stock available and will continue selling it until it is gone, but we expect that to be well before the legal sales deadline. We are also contacting customers whom we know use bromine so that nobody is caught unaware.

The main points

• You can continue using bromine granules normally until 1 October 2027.
• There is no need to stop immediately or dispose of usable supplies.
• Do not buy more than you can reasonably use before the deadline.
• Bromine tablets are not included in this particular ban.
• Hot Tubs Oxfordshire will recommend changing from bromine granules to chlorine during a drain, flush and refill.

Questions answered

• Are bromine granules really being banned?
• Why is this happening?
• Have bromine granules been found to be unsafe?
• Why are bromine tablets not affected?
• When will bromine granules disappear from sale?
• Can I continue using the granules I already have?
• Do I need to change to another sanitiser immediately?
• What should I use instead?
• How do I change from bromine to chlorine?
• Do I need to drain my hot tub on 1 October 2027?
• Can Hot Tubs Oxfordshire carry out the change for me?
• What should I do with granules left after the deadline?
• What happens next?

Are bromine granules really being banned?

Yes. “Banned” is not the terminology used in the official decision, which describes the affected substances as being non-approved and phased off the market. In practical terms, however, their sale and use will eventually be prohibited, so it is a fair description of what is happening.

Affected bromine products can no longer be supplied in Great Britain after 1 April 2027. That includes every stage of the supply chain, right through to a retailer selling a container to a hot tub owner. Their use must then stop after 1 October 2027.

This does not mean all forms of bromine are being banned. The decision covers particular methods of generating active bromine, including the method used by bromine granules. Bromine tablets use a different active substance and are not included in this particular decision.

Why is this happening?

Following Brexit, companies had to resubmit their applications to the Health and Safety Executive to keep them in the Great Britain review programme. The companies supporting the affected methods of producing bromine did not resubmit their applications.

The HSE subsequently invited another company or organisation to take over the work. Nobody did. Without a participant willing to provide the required technical dossier and support the substance through the approval process, the regulations required a non-approval decision.

This is a regulatory casualty rather than a response to a newly identified danger. In one of the quieter ironies of the post-Brexit regulatory landscape, the problem arose because the products needed fresh support through a separate GB approvals process - and no company chose to provide it.

Some stakeholders raised concerns about losing these ways of generating bromine. The HSE concluded that sufficient alternative active substances were either approved or still under review, so the withdrawal was unlikely to cause a disproportionate problem.

The full HSE decision sets out the regulatory background and the phase-out dates.

Have bromine granules been found to be unsafe?

No new safety finding prompted this decision. The HSE has not announced that bromine granules have suddenly been discovered to present an unacceptable risk when used correctly.

That does not make them harmless household products. Bromine granules are concentrated water-treatment chemicals and should continue to be stored, handled and dosed according to their label. They should never be mixed directly with other chemicals.

The important distinction is that the phase-out has resulted from the loss of regulatory support, not from the conclusion of a new safety assessment.

Why are bromine tablets not affected?

Granules and tablets may produce the same sanitiser in the hot tub, but they do so through different chemistry.

Bromine granules contain sodium bromide together with a chlorine-releasing ingredient. When added to the water, the two react to produce active bromine. It is this method of producing bromine that has lost regulatory support.

Bromine tablets contain an active substance called BCDMH (short for bromochloro-5,5-dimethylhydantoin, which thankfully never comes up in conversation). The tablet slowly releases its sanitising ingredients as it dissolves. BCDMH remains supported and under review for use in pool and spa water, so tablets are not affected by this decision.

The difference is therefore not that a tablet is considered safer than a granule because of its shape. They are separate chemical products following different regulatory routes.

When will bromine granules disappear from sale?

The legal deadline for supplying affected products is 1 April 2027, but that does not mean retailers will continue receiving stock until then.

Our supplier has already stopped supplying bromine granules. Hot Tubs Oxfordshire has a limited quantity remaining and will continue selling it until it is gone. We expect to sell out well before April 2027 and comfortably before the final date on which owners may use the product.

Other retailers and suppliers may run out at different times. The legal date is the final cutoff, rather than a guarantee of availability until then.

Can I continue using the granules I already have?

Yes. Existing bromine granules can continue to be used until 1 October 2027. This applies to private hot tub owners as well as businesses.

You do not need to stop using them now, and there is no reason to discard a sensible supply that can be used before the deadline. Continue testing your water and dosing the product normally.

It would be unwise to build up a large reserve. Any granules left after the deadline cannot legally be used, even if they were bought beforehand or remain in an unopened container. Nor should you add more than the normal dose simply to finish a container more quickly.

Do I need to change to another sanitiser immediately?

No. The phase-out period exists to give suppliers and hot tub owners time to move to alternatives.

For most owners, the sensible approach will be to continue using their remaining granules normally and change sanitiser at a convenient drain, flush and refill. That avoids wasting usable product or disrupting a water-care routine that remains legal for the time being.

You should, however, plan the change before your remaining supply runs out. Bromine granules may become difficult to find considerably earlier than the legal deadline.

What should I use instead?

Hot Tubs Oxfordshire will be recommending that customers who currently rely on bromine granules change to chlorine.

Bromine tablets remain legal, but they are not a direct like-for-like replacement for fast-dissolving granules. Tablets dissolve gradually in a floating dispenser or feeder and involve a different dosing routine. They may suit some owners, but simply replacing one scoop of granules with a tablet would not be an appropriate changeover method.

Chlorine granules provide a more familiar routine for owners accustomed to testing the water and adjusting their sanitiser level with a measured dose. Chlorine is also an established and widely available treatment for domestic hot tubs.

The right advice may still depend on the hot tub and its existing water-care equipment. Owners should follow the instructions supplied with their chosen product rather than carrying their old bromine dose across to chlorine.

How do I change from bromine to chlorine?

The cleanest way to change is during a drain, flush and refill.

Water treated with bromine contains bromide left behind by the sanitisation process. If chlorine is added to that water, it can react with the bromide and generate more active bromine. The water may therefore continue behaving as a bromine system even though chlorine has been added.

Draining and refilling removes that bromide reserve and gives the new chlorine routine a clean starting point. Flushing the plumbing at the same time also removes accumulated material from the internal pipework.

Never mix concentrated bromine and chlorine products together, either in their containers or in the same dispenser. “Both are sanitisers” does not mean they can be safely combined. Follow the directions for the new chlorine product from the beginning, including its own dosing and testing instructions.

Do I need to drain my hot tub on 1 October 2027?

The deadline means affected bromine granules must no longer be used after 1 October 2027. It does not mean that every hot tub containing water previously treated with bromine granules must be drained on that date.

In practice, owners should plan their changeover in advance rather than trying to time a final dose immediately before the deadline. A routine water change before then provides a sensible opportunity to drain, flush and begin using chlorine.

Can Hot Tubs Oxfordshire carry out the change for me?

Customers with a Hot Tubs Oxfordshire Maintenance Plan will be advised to change to chlorine as part of a service that includes draining, flushing and refilling the hot tub.

If you bought your hot tub from us but do not have a Maintenance Plan, you can book a Mini Service to have the drain, flush and refill completed for you.

If your hot tub was supplied by another retailer, we recommend contacting that retailer for advice or assistance, particularly if you are unsure about the correct draining, flushing and refilling procedure for your model.

What should I do with granules left after the deadline?

Keep any unused product in its original labelled container and continue storing it securely, away from children and other chemicals, while arranging suitable disposal.

Do not mix it directly with another product - mixing concentrated spa chemicals can be extremely dangerous. Certainly don’t pour it down a drain, place it in ordinary household waste, or add an excessive dose to your hot tub simply to get rid of it.

Contact your local authority to ask about its arrangements for household hazardous waste, as the facilities available vary between areas. If you’re unsure where to start, we recommend using the GOV.UK hazardous waste disposal guidance.

What happens next?

There is no need for bromine users to make a rushed change. Existing granules remain legal to use until 1 October 2027, and most owners should have a convenient opportunity to change during a normal water replacement well before then.

Hot Tubs Oxfordshire is contacting customers whom our records show as using bromine. We will help customers who bought their hot tub from us move to chlorine during an appropriate drain, flush and refill.

The disappearance of bromine granules will require a change in routine, but it does not mean bromine-treated hot tubs have suddenly become unsafe or unusable. There is time to use a reasonable existing supply, choose the right point to change and begin the new water-care routine properly.