The idea of limiting the cadmium content of phosphate fertilisers appeared in a Commission strategy on cadmium in 1987.
The concern underlying the strategy was the need to reduce direct human exposures to the metal and limit its accumulation in soils where it is available for uptake by crops. Cadmium accumulates in human kidneys and can cause renal dysfunction in vulnerable groups, and the margin of safety between current exposures and concentrations at which health effects can occur is relatively small.
The goal of the Commission's draft proposals is to stop the gradual accumulation in soils of cadmium from fertiliser applications and prevent agricultural land becoming unfit for food production.
Launching an eight-week internet consultation on the proposals on 1 August, Enterprise Commissioner Erkki Liikanen said: 'This draft proposal strikes a balance between the need to protect the environment on the one hand and to ensure the supply of phosphate fertiliser to EU farmers on the other.'
The Commission has suggested a lengthy phased introduction of its proposals. An initial limit of 60mg of cadmium per kilogram of phosphorus pentoxide would take effect after five years. This would be cut to 40mg/kg after a further five years, and finally to 20mg/kg after another five.
Nine Member States reported in the late 1990s that average national values for the cadmium content of phosphate fertilisers ranged between 1mg/kg in Finland - which has indigenous supplies of low-cadmium phosphate rock - and 58mg/kg in Ireland.
The limits proposed by the Commission are certainly open to dispute. Risk assessments carried out by the nine Member States came up with a wide range of predictions of the likely rate of accumulation in similar soils at similar levels of fertiliser cadmium.
However, the Commission's Scientific Committee on Toxicity, Ecotoxicity and the Environment endorsed the view that, at fertiliser cadmium concentrations of 60mg/kg or more, the metal would continue accumulating in most soils, whereas at levels of 20mg/kg or less it would at worst accumulate very slowly.
Meeting the first-stage limit of 60mg/kg is unlikely to pose problems to fertiliser manufacturers - indeed, it was proposed as the end-point of a ten-year programme which the European Fertiliser Manufacturers Association offered to the Commission by way of a voluntary agreement in 1996.
However, EFMA is deeply unhappy about the ultimate EU-wide limit of 20mg/kg proposed by the Commission, and wants it to consider a regional approach which takes account of the variability of soils and climate which has a significant influence on the rate of cadmium accumulation in soils. However, the Commission has already rejected this as unduly cumbersome.
As an alternative, EFMA wants decisions on the second and third stages postponed pending further risk assessment and the development of technologies for removing cadmium from phosphate rock or phosphoric acid before they are made into fertiliser.
The Commission, in contrast, believes that such decadmiation technologies will not be developed without the strong signal which its proposed 20mg/kg limit would send.
It is now several years since the Commission sponsored the development of a pilot-scale decadmiation process in Morocco, which supplies 40% of the EU's phosphate fertiliser from high-cadmium ores. The process has yet to be demonstrated at commercial scale - 'because of a reluctance by producers to invest in a technology for which there is currently no demand,' according to the Commission.
The proposals have sensitive trade implications. Without a breakthrough in decadmiation technology, they would make the EU heavily dependent on imports from Russia, South Africa and Jordan, which are the only countries with low-cadmium ores.
Meanwhile, Morocco and Tunisia would lose out badly, along with the Spanish and French fertiliser manufacturers who use their high-cadmium products. The Commission says it is exploring the possibility of providing further financial assistance to those countries for development of decadmiation processes.
The Commission appears confident that such technologies can be brought successfully to commercial scale, and would not impose heavy costs on farmers. It estimates that, in the UK, the use of decadmiated products would add 5.5% to farmers' phosphate fertiliser costs.