French anti-smoking campaigners launched a legal case Friday against international tobacco giants claiming their cigarette filters have helped them falsely report the level of tar and nicotine in their products.
The National Anti-Smoking Committee (CNCT) says tiny holes in the sides of the filters stop authorities being able to tell if the legal limits for the toxic substances have been breached.
The group has filed a case against the French subsidiaries of Philip Morris, British American Tobacco, Japan Tobacco International and Imperial Brands for endangering lives.
Contacted by AFP, Philip Morris declined to comment, while the other three companies had yet to respond.
Such filter holes have been a part of cigarette design since the 1950s, initially marketed as making the smoke lighter and healthier by adding fresh air into each puff.
But the CNCT argues the holes lower the level of tar and nicotine inhaled much more when a cigarette is being tested by a machine.
When the cigarette is smoked by a human, their fingers and lips block the holes, stopping fresh air from getting in to dilute the smoke.
"The true amount of tar and nicotine inhaled by smokers is between two and 10 times higher for tar and five times higher for nicotine," the CNCT alleged, citing academic studies from 1998 and 2006.
"Smokers who think they are smoking a packet a day are in fact smoking the equivalent of two or ten."
The campaign group said anti-smoking campaigners in the Netherlands and Switzerland had launched similar cases.
The CNCT said tobacco giants had long acknowledged the design problem themselves, citing a legal case dating back to 1982 when Philip Morris and two other companies sued British American Tobacco.
The company had launched a new brand, Barclay, touted as 99 percent tar-free -- but its rivals argued in the suit that the holes did not work when blocked by the smoker's hand.
The French case was lodged with Paris prosecutors on January 18, the CNCT's lawyer Pierre Kopp told AFP.
Some 97 percent of cigarettes have ventilation holes in their filters, according to the CNCT.
Research published in the Journal of the National Cancer Institute in the United States last year said such filters could be linked to the rise in a specific kind of lung cancer.
The researchers believe rates of adenocarcinoma, the most common form of lung cancer, have been rising while others have been declining, because the holes allow smokers to take deeper drags.