Dr Ian Carney, from the group safety, health and environment department at ICI's headquarters in London, says: "Creeping categorisation of chemicals can lead to controls which ignore the individual characteristics of those chemicals."
Dr Carney, through the Chemicals Industry Association, has been lobbying Brussels to prevent chemicals being lumped together in certain categories, rather than being treated on a case-by-case basis as at present.
The CIA fears the implications for British industry could be enormous. Alongside worries about unjustifiable bans on trade in certain chemicals, with the consequent loss of jobs and profits, it says consumers will also suffer as a consequence.
The origin of its concern is the so-called precautionary principle, adopted at the Rio Summit in 1992, to which Britain was a signatory. This states: "In order to protect the environment ... where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation."
The first fruits of the principle have been seen, in the shape of a new grouping of chemicals labelled persistent organic pollutants (or Pops). A dozen chemicals have been placed in this group. Most of them are extremely toxic, but among them is the insecticide DDT.
Elizabeth Surkovic, at the CIA, said many Third World countries still relied on DDT as an effective means of controlling malaria, which is spread by mosquitoes.
The CIA believes the solution is to continue to apply the existing procedure and assess every chemical individually.
Ms Surkovic is worried that the new category of Pops will lead to the eventual banning of whole series of chemicals that, while potentially hazardous, can also bring significant benefits.
The United Nations Environmental Programme, which drafts and implements the rules, retorts that such concerns are exaggerated.
James Willis, director of chemicals at Unep, said there were effective alternatives to DDT that did not have the same level of toxicity.
He also rebuffed claims that the precautionary principle could lead to an overly rigid approach. "We are still working out the framework for applying the precautionary principle."
He said that UN meetings scheduled for February would consider the issue.
Environmental activists and campaigners believe that current proposals are inadequate.
Roger Lilley, of the industry and pollution group at Friends of the Earth, said: "Case-by-case analysis clearly favours the chemical industry and places the onus on the regulator to prove the toxicity of any chemical. We believe the chemical industry should take responsibility and prove the toxicity of chemicals."