SAFETY
▸ Limits recommended for worker exposure to butter-flavor chemicals Workers in the chemical and food industries should limit their exposures to the food flavoring chemicals diacetyl and 2,3-pentanedione to avoid irreversible lung damage, the National Institute for Occupational Safety & Health (NIOSH) recommended last week. Diacetyl was once widely used to give microwave popcorn a buttery flavor until factory workers exposed to the chemical reported in the O early 2000s that they had developed serious respiratory disorders. In some O cases, 2,3-pentanedione—a Diacetyl chemical that is structural(2,3-butanedione) ly similar to diacetyl—has been used as a substitute, O despite its potential to cause the same problems. NIOSH recommends keepO 2,3-Pentanedione ing exposures below 5 parts per billion for diacetyl and below 9.3 ppb for 2,3-pentanedione during an average 40-hour work week. Short-term exposures should be no more than 25 ppb for diacetyl and 31 ppb for 2,3-pentanedione over a 15-minute period, NIOSH suggests. “We know these flavoring compounds can pose a great risk for workers who may be exposed on the job, causing serious and irreversible damage to their lungs,” says NIOSH Director John Howard.—BRITT ERICKSON
INTELLECTUAL PROPERTY
CREDIT: SHUTTERSTOCK
▸ Hedge fund manager wins U.S. drug patent challenges Hedge fund manager J. Kyle Bass’s controversial campaign of challenging the validity of U.S. drug patents scored a pair of victories in late October. In the first, the federal Patent Trial & Appeal Board determined that most of Shire PLC’s claims for its short bowel syndrome drug Gattex are invalid. The tribunal then nullified two patents related to Celgene’s cancer drugs Thalomid, Revlimid, and Pomalyst. In both cases, the board ruled that the patent claims were invalid because they were obvious in light of earlier patents and scientific journal articles. The board, part of the U.S. Patent
EPA is proposing to allow the use of Dow’s Enlist Duo herbicide mixture of 2,4-D and glyphosate on cotton.
PESTICIDES
EPA green-lights Enlist Duo herbicide EPA has cleared the way for the herbicide Enlist Duo—a combination of 2,4-D and glyphosate—to be used on genetically engineered corn and soybeans in more than a dozen U.S. states. The agency is also proposing to allow the controversial mixture to be used on cotton and to expand the number of states where it can be used. U.S. regulators first approved Enlist Duo for use on corn and soybeans in 2014, but subsequently asked a federal court to overturn the approval. The agency claimed that the herbicide’s maker, Dow AgroSciences, withheld information suggesting synergistic toxicity effects between the two ingredients. EPA reviewed additional data submitted by Dow and announced on Nov. 1 that regulators found no such effects. Dow had reported synergistic effects in a patent application for Enlist Duo, but now says that the claim was based on limited information. Additional data confirm the two ingredients do not amplify each other’s toxicity, Dow says. Environmental groups that challenged EPA’s approval of Enlist Duo are outraged by the agency’s decision. “This proposal ignores the available data and will potentially harm our environment,” says Nathan Donley of the Center for Biological Diversity, one of the plaintiffs. EPA expects to make a final decision in early 2017.—BRITT ERICKSON
& Trademark Office, has agreed to review several other patents that Bass’s Coalition for Affordable Drugs has challenged. Its next decisions are due in February 2017. The victories mark the first time a nonplayer in the drug market has successfully challenged pharmaceutical patents. The board’s decisions are likely to be appealed in federal courts.—GLENN HESS, special to C&EN
GREENHOUSE GASES
▸ India adopts law to halt emissions of HFC-23 India has a new law that controls on emissions of hyrofluorocarbon-23, a highly potent greenhouse gas. HFC-23 is a by-prod-
uct of the manufacturing of the widely used refrigerant hydrochlorofluorocarbon-22. A recent order from India’s Ministry of Environment, Forest & Climate Change asks industries to “urgently and immediately” destroy HFC-23 rather than releasing it to the environment. The ministry has directed the five registered companies producing HFC-23 to destroy the gas via incineration using “an efficient and proven technology.” The order came after Indian Environment Minister Anil Madhav Dave announced at an international meeting in October that India will eliminate HFC-23 production as part of its commitment to combat the climate threat posed by HFCs. At that meeting, countries agreed to phase out the production and use of HFCs, a group of chemicals largely used as substitutes for stratospheric ozone depleting HCFCs and hydrochlorofluorocarbons.—K.V.
VENKATASUBRAMANIAN, special to C&EN NOVEMBER 7, 2016 | CEN.ACS.ORG | C&EN
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