In December 2007, a study commissioned by the Seattle Post-Intelligencer determined that top-selling butter substitutes could release vapor from diacetyl, a chemical additive that may be hazardous when heated and inhaled over a long period of time. The dangers of diacetyl were exposed earlier this year when workers at a popcorn plant that used artificial butter with diacetyl became seriously ill. The new study may concern professional cooks who use large amounts of the butter substitutes.

“It is possible that the amount of diacetyl being released in commercial kitchens where these butter-flavored products are being used could equal or perhaps exceed what was found in the popcorn plants,” said Dr. Richard Kanwal.

In one test, the amount of diacetyl in vapor was measured at 234 parts per million. It was estimated that diacetyl levels of 2 or 6 parts per million entered worker’s “breathing zones” above the skillet.

There are only two cases of cooks becoming injured by inhaling vapor from cooking products, one of which occurred in the mid-1990s. The young cook had a severe lung disease, and used PAM cooking spray on the job.

“Nobody knew why this woman had terrible lung disease,” said Dr. Kathleen Kreiss. “It was known that she used PAM in her cooking but then no one thought to link it to diacetyl.”

PAM was one of the products tested in the study, which found a two-second spray into a heated pan released a high level of diacetyl.

Kreiss said she and others have been concerned about cookers’ health since three studies found food production workers have an unexplained high prevalence of obstructive lung disease, something diacetyl vapors may cause.

“I have been suggesting for several years now that this (use of flavorings and food production and service workers) needs to be examined,” she said.

The study tested 22 popular cooking products, and found the following results:

• Two real butters were analyzed and diacetyl was found in a range of 7 ppm to almost 16 ppm.
• In all the margarine and shortening products, levels of 7 ppm to almost 180 ppm were present.
• A butter-flavored cooking spray released more than 164 ppm of diacetyl.
• Butter-flavored cooking oils used by professional cooks ranged from 23 ppm to 234 ppm.
• Two brands of oil for popping corn came in at 1,062 ppm and 1,125 ppm.

Health specialists have previously reported that repeated exposure to diacetyl has led to three workers’ deaths, destruction of the lungs of many, and sickened hundreds of others.

Manufacturers of the products containing diacetyl, however, point out that the Food and Drug Administration (FDA) said diacetyl is safe.

“The FDA classifies diacetyl as ‘Generally Recognized as Safe’ for consumption,” said Lori Fligge, media relations director for the manufacturer one of the products tested, Cargill.

However, the FDA’s diacetyl safety studies were conducted in the 1980s. The tests conducted only examined the hazard from eating the additive, not inhaling its vapor.

“Diacetyl is just one of scores of substances that shouldn’t be allowed to carry what is in effect a government-sanctioned anti-warning giving the false impression that untested food additives are safe,” said Dr. David Egilman, a professor at Brown University and the head of Never Again Consulting, a research group that has investigated many worker safety issues, including diacetyl.

Source: Andrew Schneider, [“Flavoring additive puts professional cooks at risk,”’(http://seattlepi.nwsource.com/national/344277_diacetyl21.html) Seattle Post-Intelligencer, December 21, 2007.