Widnes was founded in the 1950s as a new pesticide mixing and distribution centre for Imperial Chemicals Industries. The site consisted of a chemical tanker washing and storage area and a main shed of 160,250 sq ft (15,000 m2). On 18 April 1968 an aerial photograph recorded 27 chemical storage tanks on the site, of which 14 have been identified as containing Granox or the raw materials used to make it, including alpha and gamma HCH, Lindane, Pentachlorophenol, Dinitro-o-cresol, and Dinoseb.
In addition to manufacturing Granox, the Widnes site was used to prepare and load pesticides supplied by other manufacturers into tankers and bulk road vehicles for distribution in bulk in the UK. Some of the chemicals processed and/or stored at Widnes, including Granox, were used as pesticides in agriculture, while others were employed in the textile and paper industries, and in the provision of timber treatment and weed control.
Granox (short for Granulated Aldrin OXide) was a soil insecticide applied to crops such as wheat, oats and barley. The main pesticide in Granox was aldrin, a synthetic chlorinated hydrocarbon insecticide and chemical warfare agent of low acute toxicity but persistent in the environment. Aldrin was classified by the World Health Organization (WHO) as an extremely hazardous pesticide.
The Granox plant at Widnes was closed down in 1978 and in 2002, the whole of the ICI site at Widnes was vacated. The Granox Widnes site has since been acquired by chemical company INOVYN, which owns and operates a chlorine plant on the adjoining site.
Since 2011, the INOVYN site has been the subject of a long-running investigation into the discovery and clean-up of historic chemical contamination at the site, particularly in relation to Granox. In the final judgement at Chester Crown Court in December 2019, four Inovyn employees were convicted of contravening Regulation 11(1)(a) of the Environmental Permitting (England and Wales) Regulations 2016.
