2010 TLV changes

                                          Citral                          5 PPM

                                          Cotton Dust                 0.1 MG/M3

                                          Cresol                         20 MG/M3

                                          Dieldrin                        0.1 MG/M3 as Inhalable fraction and vapor

                                          Hydrogen Sulfide           1 PPM TWA 5 PPM STEL

                                          MIBK                            20 PPM TWA 75 PPM STEL

                                          Alpha-Methyl Styrene      10 PPM

                                          Mineral Oil (pure)           5 MG/M3 as Inhalable fraction

                                          Mineral Oil (Poorly or mildly refined)  As low as feasible

                                          Portland Cement            1 MG/M3

                                          Thallium                        0.02 MG/M3 Inhalable

                                          Thionyl Chloride             0.2 PPM STEL

                The Threshold Limit Values (TLV's) are published annually by the American Conference of Governmental Industrial Hygienists (ACGIH)  www.acgih.org