Herbicide 2,4,5-T (Hansard, 20 June 1980)

§ Mr. Peter Walker

This information, which related to usage rather than sales of these products, was not the responsibility of the advisory committee. Usage estimates prepared by my Department were given to the committee in December 1978 and published in its March 1979 report. They were later quoted by the Royal Commission on Environmental Pollution in its seventh report (Cmnd 7644).

Annual usage of active ingredient was estimated at about 1 ton each for forestry, agriculture and other purposes, i.e. some three tons in all. It is now clear that far more was being used in the late 1970s, and my inquiries suggest three main reasons why the estimates were deficient.

First, in those days there seems to have been a general assumption, as illustrated by a weed research organisation study published in 1977, that almost all 2,4,5-T sold in Britain was used for woody plant control" ; and again that the use of the herbicides in Britain is small and almost confined to forestry". This may have been so in the late 1960s when the Forestry Commission was using upwards of 40 tons a year, mainly to clear derelict woodlands ; but the Commission's usage, temporarily suspended in the early 1970s, had declined to about 1 ton by 1977.

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Similarly, local authority returns of usage, e.g. in parks and gardens, showed a decline of over 40 per cent. to less than 0.3 tons, between 1973 and 1978. However, there are now indications that this decline in use of 2,4,5-T as a brush-killer, notably in forestry, may have been either accompanied or followed by an increase in its use on farms, alone or in mixtures, and especially for general or spot treatment of permanent grassland.

Secondly, Departmental pesticide usage surveys had not then extended to permanent grassland. Since 1965, these small sample surveys had been concentrated on arable and horticultural crops in England and Wales and the results, most of which have already been published, showed very little use of 2,4,5-T e.g. in orchards and hop gardens, with an estimated total of about 1¼ tons a year.

The results of the 1978–79 first-ever permanent grassland survey of England and Wales, which will incorporate data from Scotland, have still to be processed ; and spot treatments are being further studied because of the margin for error—for example, 9 tonnes would be needed to give spot treatment to 1 per cent. of permanent grassland in England and Wales.

Finally, the estimates were based only upon available returns rendered by public authorities, and available data from surveys at the point of use; and in either case these differed over both space and time. For example Northern Ireland was not included in any of the returns and surveys. Again, at one extreme permanent grassland survey data had still to be collected whilst, at the other, the main data on non-agricultural uses related to 1972–73 as published in the Department of Environment's Pollution Paper No. 3 (where 2,4,5-T herbicides are mentioned among pesticides used by British Rail and the CEGB, and where NCB usage was quoted at 0.9 tonnes).

I accept that there will always be difficulties in obtaining precise figures for overall United Kingdom usage of any pesticide at any given time; but if we are to make the best possible estimates I consider that, as the Royal Commission on environmental pollution has since recommended, other organisations concerned should be involved ; and in particular manufacturers' and suppliers' 709W organisations should be approached for marketing data.

This is contrary to past practice, but I have insisted on it for the new survey of current usage announced in the reply given to my hon Friend on 22 May; and for which the starting point will be figures which the industry obtained for me last month, i.e. that 46, 51 and 58 tonnes were put on the market in the three years 1977–79 for eventual use in the United Kingdom. Figures for United Kingdom usage of these herbicides have to be distinguished from figures for imports of commercial 2,4,5-T for formulating ; all 2,4,5-T used in this country is imported, but over 60 per cent. of all the imported material is re-exported in formulated products.