"Our standards permit both types of alarms," said Chris Dubay, NFPA's Vice-President of Codes and Standards.
"What we do know is that a significant amount of fires start as flaming, which one type of technology is better at and a significant amount of fires start as smoldering which a different type of technology is better at," Dubay said. "The problem we have is that you can't always tell what kind of fire you're going to have."
newsnet5.com's investigation also found U.S. smoke alarm standards are not safe enough for others.
David Isaacs helped write Australian smoke alarm standards and said, "We determined that the only detectors that would give a measured, high probability of warning in time for the egress paths to remain safe were photoelectric."
Isaccs argues U.S. consumers are being left in the dark without sufficient information about both technologies that has been known for decades.
While experts disagree on types of technologies, fire victims point tragic results.
Dean Dennis lost his daughter and four of her friends in a 2003 house fire near the Ohio State campus.
Dennis says only ionization alarms were found in the home.
His daughter died of smoke inhalation.
As a result, Dennis has launched his own campaign to urge municipalities and state government to back only photoelectric alarms.
And in September of 2013, a father and six children died in a trailer fire in Tiffin, Ohio.
Reports indicated the alarm was sounding — but no one got out in time.
newsnet5.com's investigation found the alarm the family depended on was an ionization alarm - the very type that often responds more slowly to smoke.