Labor Secretary Initiates Peer Review of Diacetyl Health Risks
The U.S. Department of Labor (DOL) recently announced the availability of its semiannual regulatory agenda, which includes plans to conduct a peer review of the health effects and risks associated with diacetyl in the workplace. According to DOL, “emerging hazards such as food flavorings containing diacetyl and airborne infectious diseases place American workers at risk of serious disease and death.” Although DOL opted not to grant an emergency temporary standard petition filed by two workers’ unions in 2006, the department’s Occupational Safety and Health Administration (OSHA) has noted that “evidence from NIOSH [the National Institute for Occupational Safety and Health] and other sources indicated that employee exposure to diacetyl and food flavorings containing diacetyl is associated with bronchilitis obliterans, a debilitating and potentially fatal disease of the small airways in the lung.” As part of its intent to develop diacetyl regulations, OSHA in July 2009 completed a panel report on a draft standard in accordance with the Small Business Regulatory Enforcement Fairness Act (SBREFA) and has proposed to review the scientific data for diacetyl in October 2010. “Experimental evidence has shown that inhalation exposure to artificial butter flavoring vapors and diacetyl damaged tissue lining, the nose, and airways of rats and mice,” stated DOL in its December 7, 2009, Federal Register notice.
Members of Congress, public health activists and physicians are among those who have requested government action on diacetyl. In a November 25, 2009, letter to Solis, U.S. Senator Sherrod Brown (D-Ohio) urged that final rulemaking on diacetyl “proceed with the sense of urgency that this issue deserves” because “it has been ten years since the danger of diacetyl was first documented.”
In a related development, NIOSH has issued a November 2009 report claiming that some diacetyl substitutes, such as 2,3-pentanedione, 2,3-hexanedione and 2,3-heptanedione, “may also share diacetyl’s mechanism of toxicity.” In response to a confidential Health Hazard Evaluation request, NIOSH staff apparently conducted a medical survey of workers at a General Mills, Inc. bakery mix facility in Los Angeles, California. Although the facility had phased out a buttermilk flavoring that contained up to 20 percent diacetyl, it had reformulated its products using 2,3-pentanendione. After conducting spirometry on 24 (59 percent) of the current workers, NIOSH found that while study participants did not exhibit the “fixed airways obstruction as seen in flavoring-related bronchiolitis obliterans,” they nevertheless “had higher than expected rates of shortness of breath, physician-diagnosed asthma, and a restrictive pattern on spirometry, compared to U.S. adults.” In addition, researchers noted that the increasing carbon chain length of 2,3-pentanedione and other alpha-diketone compounds “would be predicted to reduce water solubility and result in deeper lung penetration and perhaps greater toxicity.” NIOSH has thus recommended that management “continue to limit exposures to flavorings through a combination of engineering controls, work practices, and respiratory protection.”
