The finding, by an independent expert group, should settle a row triggered by the Carlton Television programme The Cook Report which claimed in November 1994 that the antimony and phosphorus found in PVC mattresses could release toxic fumes that suffocated babies.
But a Carlton spokeswoman yesterday insisted that the "respected scientists" quoted in the programme "did not and do not agree with the findings of the Department of Health". However, she did not know whether they had seen the new findings.
The programme, produced by Barry Richardson, a research scientist, and New Zealand-based chemist Jim Sprott, claimed the effect was responsible for about one in ten cot deaths - about 400 - in the UK each year. The Tory government was accused of ignoring evidence that might have saved lives, and thousands of mattresses were withdrawn from sale.
As a result, the chief medical officer Sir Kenneth Calman drew together a panel of 12 experts,who published the new study; their interim report in 1995 also showed that there was no evidence to support the theory, as did research published last year into 148 babies at Great Ormond Street Hospital in London.
Joyce Epstein, secretary-general of the Foundation for the Study of Infant Deaths (FSID), said the finding "brings to a close a ghastly episode in public health scaremongering". She added: "We need serious research, not the TV kind".
The only clear evidence on the causes of Sudden Infant Death Syndrome (Sids) links it to parental smoking, and also to babies sleeping on their stomach rather than on their back.