WASHINGTON — Robb MacKie, president and chief executive officer of the American Bakers Association, said the A.B.A. has cleared a major hurdle in its effort to limit flour dust threshold limit values (T.L.V.) with the announcement that the Occupational Safety & Health Administration (O.S.H.A.) has excluded the American Conference of Governmental Industrial Hygienists (A.C.G.I.H.) threshold limit values as part of its revamping of the Hazard Communication Standard (H.C.S.). Mr. MacKie said O.S.H.A.’s new H.C.S. proposal removes all A.C.G.I.H. T.L.V. mandates, a step the A.B.A. has pushed for during the pre-proposal stage of the rulemaking. "A.C.G.I.H. is not a consensus organization and lacks an open and transparent standard-setting process, nor does it perform scientifically-based risk assessments or independent scientifically-based peer review of its exposure limits," Mr. MacKie said. "As both A.B.A. witnesses testified, the unnecessary cost of complying with the flour dust T.L.V. would have exceeded $350,000 per bakery."