The Ultimate Guide to Buffer Zones

Spray buffer zone regulations are getting increasingly complex, so to stay on the right side of the law all growers, operators and advisors must be clear of the rules before venturing out with the sprayer.

Sprayer BZ

Bayer’s applications & stewardship coordinator Alice Johnston highlights the main areas to be aware of.

What are aquatic buffer zones?

Buffer zones are an area of cropped land adjacent to watercourses (including ditches and dry ditches) that cannot be sprayed.

They are designed to protect aquatic organisms (including plants, fish, and insects) from potential toxicity caused by some plant protection products, where a risk has been identified during the approval process.

Many, but not all, products have a minimum buffer zone that must be adhered to when used next to a watercourse.

Measured from the top of the bank, distances vary from 1m for dry ditches up to 30m, but in some cases this can be reduced by following certain conditions.

What’s changing?

Since the introduction of buffer zones in the 1990s, the rules have evolved and there are now three main schemes, as outlined below:

  1. LERAP scheme
  2. Interim scheme
  3. Drift Reducing Technology (DRT)

 There is also a fourth scheme specifically to protect insects and wildlife on uncropped land (see Non-Target Arthropod Buffer Zones).

Buffer zones have historically been specific to the product rather than the crop, but this is changing and all products are likely to have crop-specific buffer zones in future.

 1.       LERAP scheme

  • Local Environment Risk Assessment for Pesticides
  • Introduced in 1999
  • Allows for buffer zones to be reduced to as little as 1m when certain technology (e.g. low drift nozzles) or lower application rate is used – only applies to products classed as “category B”
  • Operators must complete a LERAP reduction assessment prior to application and keep records for three years
  • Some products are not eligible for buffer zone reduction under LERAP – applies to any “category A” products
  • The LERAP scheme is likely to be phased out at some point, but timescales are unclear so existing arrangements remain in place for the foreseeable future
  • The LERAP assessment process will probably remain in place when the LERAP scheme is phased out.

 2.       Interim scheme

  • Introduced in late-2011 to help address difficulties getting new products authorised, to aid the re-registration of older chemistry and to give the UK similar flexibility as other EU members
  • Offers more flexibility than the LERAP scheme by setting crop-specific buffer zones for individual products
  • The size of buffer required for all approved crops is clearly shown on the label
  • Buffer zones <5m can be reduced by following the LERAP reduction assessment process
  • Buffer zones >5m cannot be reduced
  • The interim scheme is likely to replace LERAP “A” & “B” categories as products come up for re-registration by the Chemicals Regulation Directorate (CRD) and is already on many newly-approved products.

 3.       Drift Reducing Technology (DRT)

  • This is the most stringent buffer zone scheme and gives users access to certain products that would have otherwise struggled to gain regulatory approval under the LERAP or interim schemes by making use of the latest low-drift technology
  • Crop-specific buffer zones are fixed, regardless of watercourse size or application rate used, so cannot be reduced
  • Label specifies three-star low-drift equipment and operating conditions must be used (e.g. 3* nozzles, operating pressure, etc.) up to 30m from any watercourse
  • Within that 30m, compulsory no-spray zones of 6, 12 or 18m may also apply, depending on crop
  • A list of accredited low drift equipment can be found at

How do I know which scheme applies?

Many product labels still show the older LERAP categories, but newly approved chemicals (including those that have been re-registered) could have either the LERAP, interim or DRT scheme on the label.

Only one buffer zone scheme applies to any product and details will be clearly shown on the label.

Because the interim and DRT schemes set crop-specific buffer zones, it is possible any one product will have several different buffer zones outlined, so check the label carefully before spraying.

What if I mix products requiring different buffer zones?

Whenever tank mixes contain two or more products with different buffer zone rules always abide by the most restrictive label conditions.

The rules are legally binding for the use of most products so breaching the regulations could result in enforcement action, including prosecution, against the operator or employer.

Non-target arthropod buffer zones

  • This additional scheme aims to protect insects and wildlife in uncropped land, such as permanent grass margins, field boundaries and hedgerows
  • Product-specific
  • The zones are non-reducible and measured from the edge of cropped land
  • Temporary stewardship margins (e.g. wild flower mix) are classed as ‘cropped land’ so could count towards the arthropod buffer zone. Precautions should be taken to reduce drift onto margins though
  • Details are explained in the “Directions for use” section of the label
  • Arthropod buffers are advisory for some products but compulsory conditions of use for others, so check the label carefully.