June 3, 2008
"Published condom breakage studies typically report the percentage of failures but rarely provide any evidence on the mechanism of failure," explained the study authors.
Over a seven-year period, broken condoms returned to a supplier (SSL, Durex) via consumer complaints were examined to determine the cause of failure. In addition, some customers who reported breakage but did not return condoms were sent a questionnaire on the causes of breakage. Theories proposed for the mechanism of breakage were then investigated on a laboratory coital model.
A total of 972 returned condoms made from natural rubber and polyurethane were examined, with visible features on those that were broken classified. Evidence gathered from examining returns, questionnaire response, and the coital model strongly suggest a single predominant failure mechanism the authors termed "blunt puncture," where the tip of the thrusting penis progressively stretches one part of the intact condom wall until it eventually breaks.
"Blunt puncture appears to be the mechanism of breakage responsible for more than 90 percent of condom breakage not attributable to misuse," the authors concluded. "Knowledge of the main mechanism of breakage should help develop better user instructions, better test methods, and, ultimately, better condoms."