Chemical Substances and Other Issues Under Study (TLV®-CS)

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 and physical agents may move forward as an NIC or NIE in the upcoming year, based on their status in the development process. Tier 2 consists of those chemical substances and physical agents that will not move forward, but will either remain on or be removed from the Under Study list for the next year. For more information, please see the ACGIH® TLV®/BEI® Development Process


Tier 1 (may move forward with an NIC proposal in 2021) 

Chemical Substances

Antimony hydride
Acetamiprid
Bensulfide (added 7/22/2020)
Benzene
Benzoic acid and Alkali
     Benzoates (added 7/22/2020)
Buprofezin
1,3-Butadiene
Carbon monoxide
Clothianidin
Copper
Cyclopentane
Cyromazine
Diazinon
Dicamba
1,2-Dichloropropane
Difluorodibromomethane
Dimethenamid-P (added 7/22/2020)
Dinotefuran
Enflurane
Epichlorohydrin
Ethyl benzene
Ethyl ether
Fenoxycarb (added 7/22/2020)
Fluorides
Furan
Furfural
Furfuryl alcohol
Glycidyl Methacrylate (added 7/22/2020)
Glyphosate
Halothane
Hexachloronaphthalene
Imidachloprid
Iodine and Iodides
Lead and inorganic compounds
Malathion

2-Methyl-2-butene
Neonicotinoids
Nitric acid
Nitroglycerin
n-Propyl nitrate
o-Toluidine
Parathion
Phenothiazine
Phosgene
Phosphoric acid
Phosphorus (red)
Phosphorus (white)
Phosphorus (yellow)
Prometryn
Propylene glycol dinitrate
Sevoflurane
Silicon carbide
Sodium silicate
Sodium sulfate
Subtilisins
Sulfur trioxide
Talc
Tetrachlorvinphos
Tetraethyl lead
Tetramethyl lead
Thiamethoxam
Tin, organic compounds
Titanium dioxide
Tolclofos-methyl (added 7/22/2020)
Triclopyr
Triclosan
Triethanolamine
Trimethylbenzene, mixed isomers
Welding fume
Xylene

Tier 2 (will not move forward with an NIC proposal in 2021) 


Chemical Substances

Acetyl salicylic acid
Alkyl acrylates
Antimony and compounds
Benzidine
Bifenazate
Carbon dioxide
Carbon nanotubes
Carfentrazone
Chlorodiphenyl, 42% Cl
Chlorodiphenyl, 54% Cl
Chloromethyl methyl ether
Clothianidin
Cobalt carbonyl
Cobalt hydrocarbonyl
Crotonaldehyde
Diacetyl
3,3ʹ-Dichlorobenzidine
1,3-Dichloro-5,5-dimethyl hydantoin
1,1-Dichloro-1-nitroethane
Diesel exhaust
Diiodomethyl p-tolyl sulfone
1,2-Dimethoxyethane
4,4-Dimethyloxazolidine
Ethyl acrylate
Ethylene oxide
2-Ethyl hexane-1-ol
Fluxioxonil
Formamide
Germanium tetrahydride
Hafnium and compounds
Hydrogen peroxide
Indium and compounds
Isoprene
4,4ʹ-Isopropylidene diphenol

Lindane
Manganese cyclopentadienyl tricarbonyl
Methyl acrylate
2-Methylcyclopentadienyl manganese
     tricarbonyl
Methyl Naphthalene mixture
     (added 7/22/2020)
Methyl n-butyl ketone
Methylene bisphenyl isocyanate
Metribuzin
n-Butyl isocyanate
1-Naphthylamine
2-Naphthylamine
Nickel and inorganic compounds,
     including Nickel subsulfide
Nitroglycerin
Octachloronaphthalene
Pentaborane
Phenylenediamine (o, m, p)
Propane sultone
Quinone
Resin acids
Silicic acid
Sodium hypochlorite
Stoddard solvent
Tetrachlorophthalic anhydride
1,2,3,6-Tetrahydrophthalic anhydride
Trichloronaphthalene
Trifloxystrobin
Trimethyl phosphite
Uranium and compounds
Vinylidene chloride
Vinylidene fluoride
Other Issues Under Study
Appendix H: Reciprocal Calculation Method for Certain Refined Hydrocarbon Solvent Mixtures


Chemical Substances Removed from Under Study Effective 7-22-2020 

Aluminum sodium dioxide
Dipropylene glycol methyl ether
     (previously listed as
     2-Methoxymethylethoxy propanol)
2,3-Epoxypropyl methacrylate
Ethylene glycol dinitrate
sec-Hexyl acetate
Imazosulfuran
Isopropylamine
Ketene
m-Methylcyclohexanone
o-Methylcyclohexanone
p-Methylcyclohexanone
Mica
Perchloryl fluoride
Prometon
Toluene
Trichlorfon
Triflumizole