If you find you have to dispose of garden chemicals, follow these guidelines:
Avoid making excess solution
When making up solutions from concentrates fill a watering can or jug rather than diluting in the sink or with the use of a hose pipe. Make up less solution than you believe is required, as it is far easier to mix up more than it is to find additional areas to apply excess spray to.
If you do find you have left over solution after spraying, you will have to find a patch of permitted plants or weeds to spray the excess onto. Excess solution should never be poured down the drain or onto bare soil, as it will contribute to the build up of chemical residues in the ground water.
Disposing of empty containers
Empty pesticide and weedkiller containers which have held concentrated liquids (ie: those requiring dilution before use), should be rinsed three times, adding the washings to the final spray solution. The empty container can then be placed in the household waste.
Empty pesticide and weedkiller containers that have held Ready-to-Use products can now be recycled, following the findings of a Defra research project and report on the recycling of home gardener pesticide containers. Note this does not apply to containers containing concentrate (see above).
Disposing of surplus chemicals
Never dispose of surplus pesticide or weedkiller down drains or in watercourses. If disposal is unavoidable, small quantities should be diluted and sprayed onto permitted plants according to the label instructions, avoiding ponds, watercourses and ditches, and following label recommendations for avoiding harm to wildlife.
With the recent withdrawal of many garden chemicals, gardeners may possess surplus stocks of pesticides that they are legally not allowed to use. When pesticides are withdrawn from the market for economic reasons there is usually a two-year grace period in which to use up remaining stocks. More information on which products are withdrawn or approved can be found on the Health and Safety Executive website.
Contact your local authority's waste disposal section for disposal of larger quantities of out-of-date, surplus, or withdrawn pesticides, as they can advise on which household sites will accept chemicals. Locate your nearest local authority chemical disposal facility on Crop Protection Association website.
When taking surplus, withdrawn, or out-of-date chemicals to a waste disposal facility, ensure that containers are carefully sealed and clearly labelled with the name and active ingredient of the product. Do not mix different chemicals.
If you come across old pesticides or unlabelled containers (when purchasing a new property, for example) again contact your local authority's waste disposal section.