A garden pest with a regulatory history
Slugs are a garden pest rather than a household one, but the rules on controlling them changed sharply in recent years. Metaldehyde, once the main active ingredient in slug pellets, is now banned for outdoor use in Great Britain. This article summarises what the government announced, the reasons it gave, and what it recommended instead. It covers Great Britain, meaning England, Scotland and Wales, and says what could and could not be established about Northern Ireland.
What was announced
On 18 September 2020, the Department for Environment, Food and Rural Affairs and the Health and Safety Executive announced that the outdoor use of metaldehyde, a pesticide used to control slugs on farms and in gardens, would be banned in Great Britain from the end of March 2022. The decision took into account advice from the UK Expert Committee on Pesticides and the HSE about the risks metaldehyde poses to birds and mammals.
A Defra media blog post explained the reasoning in more detail. It said metaldehyde has the potential to harm birds and mammals that eat slug pellets, contaminated slugs, or other creatures that have consumed pellets or slugs. It quoted the farming minister saying the scientific evidence was clear and that the risks to the environment and wildlife were too great.
The timeline
The ban applied to all users across Great Britain and was phased over 18 months to give growers time to switch. The blog post says that from 31 March 2021 no further supply would be permitted, but distributors could still sell stocks and use could continue until 31 March 2022. From 1 April 2022, it said, it would be illegal to sell and use metaldehyde products. The press release similarly said metaldehyde would be phased out by 31 March 2022 so growers and gardeners had time to switch.
For a gardener today, the practical consequence is that any metaldehyde pellets found in a shed are products you should not use. The press release said small quantities of product for gardens should not be disposed of at home and can be disposed of through local authority waste facilities. Check your own council’s arrangements before taking products in.
What the government recommended instead
Both government documents point to pesticides containing ferric phosphate as authorised for controlling slugs on a range of crops and in gardens, and say they do not pose the same risks to wildlife and the environment as metaldehyde pellets. That is a statement about relative risk made by the government at the time of the announcement, and it is not a claim that any pellet is risk-free. Always follow the label.
The announcement also listed non-chemical options, described as cultural techniques: planting slug-resistant crop varieties, selectively timing irrigation and harvest, and sowing seeds more deeply into the soil. Those were framed mainly for growers, but the principle of adjusting timing and variety applies to allotments and vegetable patches as well.
What about Northern Ireland?
The announcements cited refer to Great Britain, so they should not be assumed to apply in Northern Ireland. The Department of Agriculture, Environment and Rural Affairs (DAERA) has a slug control page written for combinable crops that lists three active ingredients used in slug pellets: methiocarb, ferric phosphate and metaldehyde, and refers to a Metaldehyde Stewardship Group. That page is undated in the version cited, and it addresses farm crops rather than gardens, so it does not tell you the current legal position for a home gardener in Northern Ireland. If you garden there, check DAERA or the Health and Safety Executive for Northern Ireland before buying or using any slug product.
Reading product claims after a ban
Ban announcements often generate confusing marketing. Slug products sold today should not contain metaldehyde for outdoor use in Great Britain, so a pack that does is either old stock or should be treated with caution. Look at the active ingredient on the label, not the brand name, and be sceptical of claims that a product is “safe for wildlife” without saying what it contains. The government’s own statement compared ferric phosphate with metaldehyde; it did not endorse any particular brand, and it did not say that ferric phosphate products need no care in use, so keep pellets away from children and pets and follow the label.
If you use pest controllers for garden work, ask what active ingredient they use and how it is applied.
The bottom line
Outdoor use of metaldehyde slug pellets has been illegal to sell and use in Great Britain since 1 April 2022, following advice about risks to birds and mammals. Government guidance points to ferric phosphate products and cultural methods instead, and small quantities of old product should go to local authority waste facilities rather than being thrown away at home. Northern Ireland was not covered by the announcements checked here, so gardeners there should confirm the local position first.
Sources
- Defra, Health and Safety Executive, “Outdoor use of metaldehyde to be banned to protect wildlife (press release, 18 September 2020)”
- Defra in the media, “Ban on the use of metaldehyde announced (21 September 2020)”
- Department of Agriculture, Environment and Rural Affairs (Northern Ireland), “Slug control”