When should a journal article be retracted?

The editor of the journal Food and Chemical Toxicology (FCT), Dr A. Wallace Hayes, has decided to retract the study by the team of Prof Gilles-Eric Séralini, which found that rats fed a Monsanto genetically modified (GM) maize NK603 and tiny amounts of the Roundup herbicide it is grown with suffered severe toxic effects, including kidney and liver damage and increased rates of tumours and mortality.

But as this article points out, the retraction goes beyond the guidelines of the Committee on Publication Ethics (COPE), of which FCT is a member.  The guidelines state that the a journal should consider retracting a paper if:

• they have clear evidence that the findings are unreliable, either as a result of misconduct (e.g. data fabri- cation) or honest error (e.g. miscalculation or experimental error)
• the findings have previously been published elsewhere without proper crossreferencing, permission or justification (i.e. cases of redundant publication)
• it constitutes plagiarism
• it reports unethical research

But none of these applied to the paper by Séralini et al. The journal found "no evidence of fraud or intentional misrepresentation of the data" but that there " is a legitimate cause for concern regarding both the number of animals in each study group and the particular strain selected."

Suppose, then, that the biggest flaw of this paper is that its results are inconclusive.  Does that mean it should be retracted?  Does it mean that it never should have been published?

This paper has been out for over a year and has been hotly debated. I don't think it serves science or the general public to retract it.

Morever, it is on a topic that involves human and other animal health and the actions of major corporations like Monsanto.  Even if inconclusive, it can serve as a spur for other research to either confirm or disconfirm.  Interested citizens can use this information to decide for themselves whether to take action in various campaigns concerning GMOs.

What is this retraction really about?  The first article I linked to offers some interesting speculations, which I leave as an exercise for the reader.