NEWS


• 07/29/2020 - OARS WEEL documentation for n-Methyl-2-pyrrolidone (NMP). The OARS WEEL committee has reviewed the OARS WEEL value for n-Methyl-2-pyrrolidone (NMP). The document is available for a 45-day public comment period. If you would like a copy of the public comment draft so as to submit comments, please send a request to Dr. Patricia McGinnis at mcginnis@tera.org. Comments are due by September 14, 2020 to mcginnis@tera.org.

• OARS WEEL 2020 Roster has been added below. Click Here.


NEWS ARCHIVES (pdf) Click Here



The OARS-WEEL Committee consists of volunteer experts dedicated to the science of setting occupational exposure levels. The Committee strives for a balance of toxicology and industrial hygiene professionals with a broad base of experience from industry, government, academia, and consulting services. Each member serves on the Committee solely in his/her individual capacity and not as a representative of his/her employer, organization and/or agency.

OARS-WEEL 2020 Executive Committee


Chair: Janet Gould, PhD, DABT, CIH
Vice Chair: Ann Parker, MS
Secretary: Leslie Beyer, MS, DABT, CIH
Past Chair: Dan E. Arrieta, MS, PhD, DABT

OARS-WEEL 2020 Committee Members


Stacy Barnett, MS, CIH
Joel Bercu, PhD, MPH, DABT
Bill Brock, Ph.D., DABT, Fellow ATS
Courtney M. Callis, MPH, DABT
David Clapin, PhD, MPA, DABT, ERT
Patrick Coin, PhD
Michelle Deveau, MSc (A), ROH, CRSP
Christine Glatt, PhD, DABT
Jessica Graham, PhD, DABT
Andrew A. “Tony” Havics, MS, CIH, PE
Sophie Jia, MD, PhD, DABT
Mark Korchinski, MSc (Tox), ERT, DABT
Emily Lent, PhD
Tom Lewandowski, PhD, DABT, ERT, ATS

Andrew Maier, PhD, CIH, DABT
Bob Nocco, MS, CIH
Patrick Owens, MS, CIH
James C. Rock, PhD, PE, CIH
Robert Roy, PhD., DABT, Fellow ATS
Karuna Sachdeva, PhD, DABT
Lawrence M. Segal, PhD, ERT
Robert Sloglund, PhD, DABT, CIH
Andrew Soiefer, PhD, DABT
Kenneth R. Still, PhD, FATS, CIH, CSP, CHMM
Henry J. Trochimowicz, ScD, DABT
Ann Tveit, PhD, DABT
Brittany Weldon, PhD



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Workplace Environmental Exposure Levels (WEELs)™ are health-based guide values for chemical stressors. The WEELs provide air concentrations intended to protect most workers from adverse health effects related to occupational chemical exposures.

Click here for the WEEL's table of values

OARS WEEL TABLE


Occupational exposure limits (OELs) are developed for protection of healthy workers; they are not intended for the general public, which includes sensitive populations such as infants, the elderly, or the infirm. OELs are based on repeated daily exposures over a working lifetime. They are normally averaged over an 8-hour workday and serve to protect against acute and chronic health effects.


Click Here to download the PDF version of the table


Substance
CAS
Source
8-Hour TWA
Ceiling or Short-
Term TWA
Last Revised
Acetone Cyanohydrin 75-86-5
AIHA
2 ppm (skin) 5 ppm (15 min, skin)
1992
Acetophenone 98-86-2
AIHA
10 ppm  
2007
Aldicarb 116-06-3
AIHA
0.01 mg/m3 (skin)
2009
Allyl lsothiocyanate 57-06-7
AIHA
1 ppm (15-min, skin,
DSEN)
1993
Aminobenzoic Acid, para- 150-13-0
AIHA
5 mg/m3  
2001
Aminotri (Methylenephosphonic Acid) 6419-19-8
AIHA
10 mg/m3  
2004
Amyl Alcohol, n- 71-41-0
AIHA
100 ppm  
2001
Benzaldehyde 100-52-7
AIHA
2 ppm 4 ppm (15-min,
DSEN)
1998
Benzenesulfonicacid, 5-chloro-2((2-Hydroxy-1
napthalenyl)-azo)-4-methyl, barium salt (2:1)
5160-02-1
AIHA
1 mg/m3  
2008
Benzophenone 119-61-9
AIHA
0.5 mg/m3  
2003
Benzoyl Chloride 98-88-4
AIHA
5 ppm (ceiling, skin,
DSEN)
2008
Benzyl Alcohol 100-51-6
AIHA
10 ppm  
2008
Butylcatechol, 4-tert- 98-29-3
AIHA
2 mg/m3 (ceiling,
skin, DSEN)
2001
Butyraldehyde 123-72-8
OARS
25 ppm (75 mg/m3)
2016
Chloramphenicol 56-75-7
AIHA
0.5 mg/m3  
2008
ChIoroisopropyI)Ether, bis-(2- 39638-92-9
AIHA
3 ppm  
2009
Chloropropane, 2- 75-29-6
OARS
50 ppm (161 mg/m3)
2016
Chlorosulfonic Acid 7790-94-5
OARS
   
2016*
Chlorotrifluoroethylene 79-38-9
AIHA
5 ppm  
2010
Cumene Hydroperoxide 80-15-9
AIHA
1 ppm (skin)
2009
Decabromodiphenyl Oxide 1163-19-5
AIHA
5 mg/m3  
2009
Decafluoropentane, 1,1,1,2,3,4,4,5,5,5- (HFC- 4310mee) 138495-42-8
OARS
225 ppm (2320 mg/m3) 700 ppm (7217
mg/m3)
2020
Decamethylcyclopentasiloxane (D5) 541-02-6
OARS
10 ppm  
2015
Decene, 1- 872-05-9
AIHA
100 ppm
2000
Dehydrolinalool 29171-20-8
AIHA
2 ppm
2007
Diallylamine 124-02-7
AIHA
1 ppm (skin)  
2009
Dibromoneopentyl Glycol 3296-90-0
AIHA
0.2 mg/m3  
2010
Dibutylamine 111-92-2
AIHA
  5 ppm (ceiling, skin)
2003
Dichlorophenol, 2,4- 120-83-2
AIHA
1 ppm (skin*)
2004
Diethylbenzenes, mixed isomers 25340-17-4
AIHA
5 ppm  
2005
Diethylene Glycol 111-46-6
OARS
10 mg/m3  
2016
Diethylene Glycol Monoethyl Ether 111-90-0
AIHA
25 ppm  
1991
Difluoroethane, 1,1- 75-37-6
AIHA
1000 ppm  
2005
Difluoroethane, 1-ChIoro-1,1- 75-68-3
AIHA
1000 ppm
1994
Difluoromethane 75-10-5
AIHA
1000 ppm  
1997
Diisobutylene 25167-70-8
OARS
75 ppm (344 mg/m3 )  
2016
Dimethyl Ether 115-10-6
AIHA
1000 ppm  
2010
Dimethyl Sulfoxide 67-68-5
AIHA
250 ppm
2003
Dimethyl Terephthalate 120-61-6
AIHA
5 mg/m3 (total)
2000
Dimethyldichlorosilane 75-78-5
AIHA
  2 ppm (ceiling)
2001
Dimethylethylamine 598-56-1
AIHA
1 ppm 3 ppm
2011
Dimethyl-para-toluidine, n,n- 99-97-8
AIHA
0.5 ppm  
2009
Dinitroanisole, 2,4- (DNAN) 119-27-7
OARS
0.1 mg/m3 (0.01 ppm)  
2014
Dowtherm Q 612-00-0,
68987-42-8
AIHA
7.8 mg/m3  
2002
Epoxybutane, 1,2- 106-88-7
AIHA
2 ppm  
2003
Erythromycin 114-07-8
AIHA
3 mg/m3  
2007
Fluoroethane, 1,1-dichloro-1- 1717-00-6
AIHA
500 ppm 3000 ppm (5-min
STEL)
2008
Furan 110-00-9
AIHA
Worker exposure by all
routes should be minimalized to the fullest extent possible.
 
1993
GlycidylMethacrylate 106-91-2
AIHA
0.5 ppm (skin, DSEN)
2000
Glyoxal 107-22-2
AIHA
0.1 mg/m3 (DSEN)  
2000
Hexadiene, 1,4- (mixed cis and trans) 592-45-0
AIHA
10 ppm
2009
Hexafluoro-2-butene, cis-1,1,1,4,4,4- (HFO
1336mzz-Z)
692-49-9
OARS
500 ppm (3350 mg/m3)
2014
Hexafluoro-2-butene, trans-1,1,1,4,4,4- (HFO
1336mzz-E)
66711-86-2
OARS
400 ppm (2680 mg/m3)
2018
Hexafluoropropane, 1,1,1,3,3,3- 690-39-1
AIHA
1000 ppm  
1998
Hexamethyldisilazane (HMDZ) 999-97-3
OARS
10 ppm 50 ppm
2018
Hexamethylene Glycol 629-11-8
AIHA
10 mg/m3  
2011
Hexanediamine, 1,6- 124-09-4
AIHA
1 ppm  
2004
Hexanediol Diacrylate 13048-33-4
AIHA
1 mg/m3 (DSEN)  
1998
Hexyl Alcohol, n- 111-27-3
AIHA
40 ppm (eye irritation)  
2011
HFE-7100 163702-07-6,
163702-08-7
AIHA
750 ppm  
1999
Hydroxybenzoic Acid, 4- 99-96-7
OARS
5 mg/m3  
2016
Isobutyraldehyde 78-84-2
AIHA
25 ppm
2002
Isocyanuric Acid 108-80-5
AIHA
10 mg/m3 (total);
5 mg/m3 (respirable)
 
2005
Isophthalic Acid 121-91-5
AIHA
10 mg/m3 (total);
5 mg/m3 (respirable)
 
1991
Isoprene 78-79-5
AIHA
2 ppm  
2004
Limonene, d- 5989-27-5
AIHA
30 ppm  
1993
Lithium Hydroxide 1310-65-2
AIHA
  1 mg/m3 (ceiling)
1999
Lithium Oxide 12057-24-8
AIHA
  1 mg/m3 (ceiling)
1999
Mancozeb 8018-01-7
AIHA
1 mg/m3 (total, DSEN)  
2008
Melamine 108-78-1
OARS
3 mg/m3  
2016
Menthol 1490-04-6
OARS
1 ppm 3 ppm (15 min)
2014
Mercaptobenzothiazole, 2- 149-30-4
AIHA
5 mg/m3 (skin, DSEN)  
2010
Mercaptoethanol 60-24-2
AIHA
0.2 ppm (skin)  
2002
Methoxypropylamine, 3- 5332-73-0
AIHA
5 ppm 15 ppm (15 min)
2009
Methoxytridecafluoroheptene isomers (MPHE) Variable
OARS
200 ppm
2020
Methyl Ethyl Ketoxime 96-29-7
AIHA
10 ppm (DSEN)  
1990
Methyl-2-PyrroIidone, n- 872-50-4
AIHA
10 ppm (skin)  
2010
Methyltrichlorosilane 75-79-6
AIHA
  1 ppm (ceiling)
2001
Monochloroacetic Acid 79-11-8
AIHA
0.5 ppm (skin)  
2004
Nitro-1,2,4-TriazoI-5-One, 3- (NTO) 932-64-9
OARS
2 mg/m3  
2014
Nitroguanidine, 1- (NQ) 556-88-7
OARS
7 mg/m3
2016
Octamethylcyclotetrasiloxane (D4) 556-67-2
OARS
10 ppm  
2014
Octanol, 1- 111-87-5
AIHA
50 ppm  
2005
Octene, 1- 111-66-0
AIHA
75 ppm  
2000
Pentaerythritol Triacrylate 3524-68-3
AIHA
1 mg/m3 (DSEN)
1999
Pentafluoroethane, 1,1,1,2,2- 354-33-6
AIHA
1000 ppm  
2009
Pentafluoropropane, 1,1,1,3,3- 460-73-1
AIHA
300 ppm  
2001
Phosphono-1,2,4 butanetricarboxylic, 2-acid 37971-36-1
AIHA
10 mg/m3  
2006
Picolines 109-06-8, 108-
99-6, 108-89-4
AIHA
2 ppm (skin) 5 ppm (15-min,
skin)
1988
Piperidine 110-89-4
AIHA
1 ppm (skin)
1996
Polyethylene Glycols (MW > 200) 25322-68-3
AIHA
10 mg/m3
2009
Polypropylene Glycols 25322-69-4
AIHA
10 mg/m3  
1997
Potassium Bromate 7758-01-2
AIHA
0.1 mg/m3  
2004
Propargyl Bromide 106-96-7
AIHA
0.1 ppm (skin)
1997
Propenoic Acid, isooctyl ester, 2- 29590-42-9
AIHA
5 ppm  
2010
Propionaldehyde 123-38-6
AIHA
20 ppm  
2002
Propylene Glycol 57-55-6
AIHA
10 mg/m3  
2004
Propylene Glycol Monomethyl Ether Acetate 108-65-6
AIHA
50 ppm
2005
Quinoline 91-22-5
AIHA
0.001 ppm (skin)  
2006
Sodium Chloroacetate 3926-62-3
OARS
0.5 ppm (2.5 mg/m3 )  
2016
Sodium Hypochlorite 7681-52-9
AIHA
  2 mg/m3 (15 min)
2010
Tetrachloropyridine, 2,3,5,6- 2402-79-1
OARS
5 mg/m3  
2016
Tetrachlorosilane 10026-04-7
AIHA
  1 ppm (ceiling)
1999
Tetraethylene Glycol Diacrylate 17831-71-9
AIHA
1 mg/m3 (skin, DSEN)  
1981
TetraethylenePentamine 112-57-2
AIHA
5 mg/m3 (skin, DSEN)
2004
Tetrafluoroethane, 1,1,1,2- (HFC-134a) 811-97-2
AIHA
1000 ppm  
2003
Tetrafluoroethane, 1,1,2,2- (HFC-134) 359-35-3
OARS
1000 ppm  
2018
Tetrafluoroethane, 2-ChIoro-1,1,1,2- 2837-89-0
AIHA
1000 ppm
2005
Tetrafluoropropene, (Z)-1-ChIoro-2,3,3,3-
(HCFO-1224yd(Z))
111512-60-8
OARS
1000 ppm
2017
Tetrafluoropropene, 2,3,3,3,- (HFO-1234yf) 754-12-1
AIHA
500 ppm  
2009
Tetrafluoropropylene, 1,3,3,3- 1645-83-6
AIHA
800 ppm
2011
Tetrahydrofurfuryl Alcohol 97-99-4
AIHA
0.5 ppm (skin)  
1993
Titanium Tetrachloride 7550-45-0
AIHA
0.5 mg/m3  
2009
Toluene Diamine, 2,4- and mixed isomers 95-80-7; 25376-
45-8
AIHA
0.005 ppm (skin)  
2010
Toluenesulfonyl Chloride, para- 98-59-9
AIHA
  5 mg/m3 (ceiling)
2009
trans-1-Chloro-3,3,3-trifluoropropylene    (HCFO
1233zd(E))
102687-65-0
OARS
800 ppm  
2013
Trichlorosilane 10025-78-2
AIHA
  0.5 ppm (ceiling)
1998
Triethoxysilane 998-30-1
AIHA
0.05 ppm  
2000
Triethylene Glycol Diacrylate 1680-21-3
AIHA
1 mg/m3 (skin)  
1981
Triethylenetetramine 112-24-3
AIHA
1 ppm (skin)  
2009
Triethylphosphate 78-40-0
AIHA
7.45 mg/m3  
2010
TrifIuoro-2,2-Dichloroethane, 1,1,1- 306-83-2
AIHA
50 ppm  
2001
Trifluoroethane, 1,1,1- 420-46-2
AIHA
1000 ppm  
1996
Trifluoroethanol, 2,2,2- 75-89-8
OARS
0.3 ppm  
2016
Trifluoroiodomethane (CF3I) 2314-97-8
OARS
500 ppm 1500 ppm
2018
Trimethoxysilane 2487-90-3
AIHA
0.05 ppm  
2010
Trimethylamine 75-50-3
AIHA
1 ppm  
2005
Trimethylchlorosilane 75-77-4
AIHA
  5 ppm (ceiling)
2001
Trimethylolpropane Triacrylate 15625-89-5
AIHA
1 mg/m3 (skin)  
1981
Trimethylolpropane Trimethacrylate 3290-92-4
AIHA
1 mg/m3 (skin)  
1981
Trisodium Phosphate 7601-54-9
AIHA
  5 mg/m3 (15 min)
2009
Urea 57-13-6
AIHA
10 mg/m3  
2007
Vanillin 121-33-5
AIHA
10 mg/m3  
2009
Vinylcyclohexene 100-40-3
AIHA
1 ppm  
2009
Vinyltrichlorosilane 75-94-5
AIHA
1 ppm (ceiling)
2002

*Value withdrawn

Substances Considered But Determined to Have an Inadequate Minimum Data Set:

Chlorine Monoxide
Methylene Butanedioic Acid 
1,3-Pentadiene

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