Home garden products: Environmental fate considerations for pesticide registration in Great Britain and Northern Ireland

When you are applying for pesticide registration in Great Britain or Northern Ireland for home garden products, the exposure assessment can differ to that required for a professional use product. Home garden plant protection products are for use in private gardens, homes or allotments. They are often for use on ornamental plants or lawns, or to control unwanted vegetation in gardens or on hard surfaces such as drives and patios.  They may also be used on house plants grown indoors.

Please also refer to Garden home.

Environmental fate and behaviour assessment for home garden products

Most home garden products are based on active substances with existing authorisations in professional products used in similar situations, doses and timings.  Use a risk envelope to a professional use when possible. Further information is provided in Risk envelope suitability for pesticide registration in Great Britain and Northern Ireland. If a risk envelope is not available, you must provide additional information.

The typically localised nature of home garden applications means an exposure assessment for groundwater is unlikely to be required. 

PECsoil values are required for overall spray applications and for a soil drench, but not for localised spot treatments. Further information on methods is included in Soil assessment for pesticide registration in Great Britain and Northern Ireland.

The risk to surface water from spray drift can be addressed by reference to an existing authorisation for a professional product via a risk envelope approach, as explained above. In the absence of an acceptable risk envelope a spray drift assessment will be required using standard assumptions to enable consideration of the acceptability of the proposed home garden use. Further information on the approaches to be taken are included in our guidance on the risk assessment of pesticides for amateur/home garden use.

An assessment of surface water exposures via drainflow is not required for home garden product use.

If the product is intended for direct use on hard surfaces a surface water assessment using HARDSPEC will need to be provided. Use the HardSPEC model to determine exposure, following the guidance in HardSPEC: Surface and Ground water exposure model for pesticide registration in Great Britain and Northern Ireland.

Standard assumptions

For regulatory purposes, when assessing environmental exposure resulting from use of home garden products, the following size areas are assumed for a typical large garden (and can be expressed as a proportion of a hectare):

Lawn   200 square metres

350 square metres

Ornamentals 50 square metres  
Fruit and vegetables 50 square metres  
Patio and paths   50 square metres  

[Source: Regulatory updates 04/2005 and 26/2009- Garden Pesticides: Guidance on Pack Size Limits]

Where application rate is not specified and instead the label states product should be applied to run-off, this is assumed to equate to an application of 1000 L of diluted product/ha.

If you require further guidance please contact HSE.


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Updated 2021-10-18