Back in December, Andrew Schneider reported in the Seattle PI that the use of diacetyl-containing cooking oils could be putting professional cooks at risk for the same severe lung disease that’s struck workers in microwave-popcorn and flavor factories. After his article came out, the Unite-Here union requested an investigation from NIOSH (the National Institute for Occupational Safety and Health), and the union’s local Seattle chapter requested one from Washington state’s Safety and Health Assessment and Research for Prevention.

Schneider now reports that both of these investigations are underway – and he also highlights two new animal studies by federal scientists documenting that low-level exposure to diacetyl can cause damage. (These are in addition to the many existing studies about the harmful effects of the butter-flavoring chemical.)

Dr. Kathleen Kreiss, chief of NIOSH’s Respiratory Diseases Field Studies Branch, is one of the NIOSH investigators who’ve been studying conditions in the kitchens of the financial offices of JPMorgan Chase and Goldman Sachs. They’re taking samples of the cooking oils and sprays the workers use, and the air that they’re inhaling:

[Kreiss] and her colleagues were looking for signs of the disease in New York when they questioned the workers on their health and work habits. Other occupational health experts attached personal air monitors to the uniforms of the cooks to sample the air they were breathing as they prepared the food. The researchers checked for ventilation systems, and checked their effectiveness. Large vacuum monitors tested the air throughout the kitchen and samples of the oils and sprays were collected. The analysis of all the samples could take weeks, Kreiss said.

But Aramark said NIOSH gave it a clean bill of health in an exit interview Thursday.

“They see no risk to our employees and say they have no concerns about diacetyl exposure,” Kristine Grow, who heads the company’s corporate communications.

However, Fred Blosser, NIOSH’s chief of public affairs, said no conclusions were reached.

“We don’t know at this time whether the cooks in these Aramark facilities have or do not have increased risk of respiratory disease. The investigators hope to learn more through medical testing, which has been scheduled for the end of the month.”

Meanwhile, Aramark has “completely eliminated butter-flavored spray oils from our entire system and we’re working to find an alternative to other oils,” Grow said.

SHARP will be doing similar work at the Washington State Convention Center and Key Arena, two Aramark-run operations in Seattle. Schneider points out that these operations are different from typical restaurant kitchens in important ways:

While NIOSH and SHARP are eager to get into commercial kitchens where diacetyl may be present, it is puzzling to some why the unions asked for the evaluation of Aramark operations. In New York, the kitchens operated just one shift and were opened to only select diners.

Even more difficult to understand is the selection of the Seattle sites.

Both the convention center and arena have bare-bone kitchens, open only when there is an event and then serving a very limited menu, prepared by cooks who switch job locations frequently. For public health investigators trying to ascertain or characterize the potential hazard to the country’s 3 million professional cooks, these kitchens selected by the unions present a very limited opportunity.

Schneider also points out that Kreiss and her NIOSH colleagues have been studying diacetyl-exposed workers since 2000, when several Missouri popcorn-plant workers were diagnosed with severe lung disease.

OSHA, on the other hand, refused to address the issue of diacetyl exposure for several years. They’ve since announced that they’ve initiated rulemaking on the chemical, and we’re eagerly awaiting news of their progress.