Guidance on Hazard Determination: Health Effects: Manufacturers and importers of hazardous chemicals must consider the available human and animal data when determining hazards and should convey that information on the MSDS ( 29 CFR 1910.1200(d)(2) and Appendix B of the HCS). Many current MSDSs do not reflect any new information regarding health effects and respiratory hazards associated with diacetyl or FFCD. The following provides guidance on additional information that must be included in the health effects section of MSDSs for these substances. All chemical manufacturers and importers of diacetyl are required under the HCS to report on the label and MSDS any new significant information they become aware of regarding the hazards of a chemical (29 CFR 1910.1200(g)(5)). Many diacetyl MSDSs currently reflect skin, eye, and respiratory tract irritation hazards associated with diacetyl, but do not provide any new information regarding all potential respiratory hazards. In addition, many MSDSs do not provide any recommendations on appropriate control measures, such as personal protective equipment. For purposes of the MSDS, the updated health hazard information noted in the above studies must be reported in the health effects section, including any signs and symptoms of exposure and recommended protective measures (29 CFR 1910.1200(g)(2)(iv) & 1200(2)(viii)). Specifically, chemical manufacturers and importers must convey information that animals exposed to diacetyl experienced damage to the nose and upper airways, including severe damage to cells lining the respiratory tract. Chemical manufacturers and importers of food flavorings containing one percent or more diacetyl must convey information in the health effects section of an FFCD MSDS regarding the human health effects; i.e., that NIOSH has reported that employees exposed to butter flavorings containing diacetyl are at risk of developing occupational lung diseases and that in one instance, similar illnesses have been found among employees producing butter and vanilla flavorings containing diacetyl. Finally, these MSDSs must convey that contact with liquid or vapors can cause irritation to the skin, eyes, nose, and throat. Chemical manufacturers and importers of any food flavoring containing one percent or more diacetyl must convey in the health effects section of the FFCD MSDS the hazard information regarding diacetyl from the animal studies previously discussed. They must also consider other available health effects information for all components greater than one percent, convey that information on the FFCD MSDS, and include appropriate hazard warnings on the labels. While the HCS does not require that mixtures be tested to determine health hazards, chemical manufacturers and importers of mixtures (such as FFCD) may choose to conduct such testing (29 CFR 1910.1200(d)(5)(i)). Where a mixture has not been tested as a whole, it is assumed to present the same health hazards as do components which comprise one percent or greater of the mixture (0.1 percent or greater for carcinogens) (29 CFR 1910.1200(d)(5)). Manufacturers of mixtures, such as FFCD, may rely on the upstream chemical manufacturers hazard determination for constituent substances (29 CFR 1910.1200(d)(5)(ii)). Mixtures are also assumed to present the same health hazards as components present in quantities less than one percent (less than 0.1 percent for carcinogens) if there is evidence that the component still poses a health risk to employees in those concentrations [29 CFR 1910.1200(d)(5)(iv)]. Physical Hazards: Manufacturers and importers of FFCD may use whatever scientifically valid data are available to evaluate the physical hazard potential of the mixture (29 CFR 1910.1200(d)(5)(iii)). For FFCD and diacetyl, the primary physical hazard of concern is expected to be flammability. A flammable liquid is any liquid having a flashpoint below 100 degrees Fahrenheit as determined by the Tagliabue Closed Tester, Pensky-Martens Closed Tester, or Setaflash Closed Tester for liquids (29 CFR 1910.1200(c)). Diacetyl has a flashpoint of 47 degrees Fahrenheit and is, therefore, a flammable liquid. Manufacturers, importers, and employers who manufacture, import, or use diacetyl must include this information on the MSDS. For FFCD, a determination must be made as to whether the mixture itself is flammable based on the flammability of its components or on a flammability test of the mixture. See more from topic source: https://www.osha.gov/html/a-z-index.html