TLV^®/BEI^® Resources

ACGIH^® has a procedure that provides the public with an indication of where those chemical substances and physical agents under study fall in the development process. Tier 1 indicates which chemical substances or physical agents may move forward as an NIC in the upcoming year. Tier 2 indicates which chemical substances or physical agents will not move forward in the upcoming year. For more information, please see the ACGIH^® TLV^®/BEI^® Development Process.

Tier 1 (may move forward with an NIC proposal in 2009)

Chemical Substances

Acetaldehyde Acetophenone Benz [a] anthracene Benzidine (added 2/3/2008) Benzo [b] fluoranthene Benzo [a] pyrene Bisphenol A Bromodichloromethane Chlorobromomethane (added 2/3/2008) Chrysene Citral Coal tar pitch volatiles Cotton dust, raw, untreated 2,4-D Diacetyl (added 2/3/2008) Dibutyl phthalate 3,3'-Dichlorobenzidine Dieldrin Diethylhydroxylamine (DEHA) Dimethylformamide

Dipropyl ketone Ethyl benzene Ethyl formate Glycerin, mist Maleic anhydride Manganese and inorganic compounds Methanol Methomyl Methyl acetate Methylacrylonitrile Methyl isopropyl ketone 2,4-Pentanedione (added 5/3/2008) m-Phthalodinitrile Piperazine dihydrochloride Polycyclic aromatic hydrocarbons (PAHs) Tantalum and tantalum oxide Thallium and soluble compounds Triethanolamine Triphenyl amine Wood dusts

Tier 2 (will not move forward with an NIC proposal in 2009)

Chemical Substances

Acetic anhydride Allyl bromide (added 5/3/2008) Allyl chloride (added 5/3/2008) Atrazine (and related symmetrical triazines) Barium sulfate Boron tribromide Boron trifluoride 1-Bromopropane (added 5/3/2008) sec-Butyl acetate Butylated hydroxytoluene (BHT) tert-Butyl hydroperoxide Calcium silicate Carbon black Chlorine (added 5/3/2008) Clopidol Creosote 1,3-Dichloro-5,5-dimethyl hydantoin Dicyclopentadiene Diethylene glycol monobutyl ether Diisobutyl ketone N,N-Dimethyl acetamide Ethyl cyanoacrylate Ethylidene norbornene Gasoline, all formulations Hexamethylene diisocyanate Iodoform (added 5/3/2008)

Isobutane Isophorone diisocyanate Methylene bis (4-cyclohexylisocyanate) Methylene bisphenyl isocyanate (MDI) Methyl formate Methyl isoamyl ketone Naphthalene β-Naphthylamine (added 2/3/2008) Nickel carbonyl Nitrogen dioxide (added 5/3/2008) Nonane Paraquat Pentachlorophenol Phthalic anhydride o-Phthalodinitrile (added 5/3/2008) p-Phthalodinitrile (added 5/3/2008) Polymeric MDI Simazine Stearates Stoddard solvent Thioglycolic acid Titanium dioxide Tributyl phosphate (added 5/3/2008) Trichloroacetic acid 1,2,3-Trichloropropane Vinyl acetate 5-Vinyl-2-norbornene

Other Issues

1. Definition of various notations.