COMPARISON OF ODOR THRESHOLDS AND PEL'S/TLV'S OF SOME SUBSTANCES

Concentrations expressed in ppm, unless otherwise stated

1. Odor Threshold < 0.5 X PEL or TLV Absence of odor suggests safe concentratio

SUBSTANCE

ODOR THRESHOLD

PEL

STEL TWA

TLV

STEL TWA

IDLH

Acetone

100

1000 750

1000 750

20,000

Ammonia

0.3-0.5

35 -

35 25

500

sec Amyl Acetate

0.002-0.08

- 125

- 125

9,000

Carbon Disulfide

0.001-1

12 4

- 10

500

Diphenyl (biphenyl)

0.01-0.06

- 0.2

- 0.2

60

Hydrogen Cyanide

0.0003-1

4.7 -

10(C) -

50

Hydrogen sulfide

0.0005-0.2

15 10

15 10

300

Sulfur Dioxide

0.5

5 2

5 2

100

Trichloroethylene

0.2

200 50

200 50

Ca

Xylene

0.1-0.3

150 100

150 100

1,000

2. Odor Threshold 0.5- 2X PEL or TLV Odor indicates possible hazard

Substance Odor Threshold PEL

STEL TWA

TLV

STEL TWA

IDLH
Acetonitrile 40 60 40 60 40 4,000
Aldrin (mg/m3) 0.25-0.4 - 0.25 - 0.25 Ca
Ethyl bromide 200 250 200 250 200 3,500
Fluorine 0.035-3 - 0.1 2 1 25
Formaldehyde 0.8-1 2 1 2* 1* Ca
Methyl chloroform 20-500 450 350 450 350 1,000
Nitrogen dioxide 1-5 1 - 5 3 50
Ozone 0.0005-0.5 0.3 0.1 - 0.1C 10
Phenol 0.05-5 - - - 5 250
Sulfuric acid 0.6-2.5 - - - 1 25

Key : PEL= OSHA Permissible Exposure Limit TLV= ACGIH Threshold Limit Value STEL= Short Term (15-30 min) Exposure Limit

TWA= 8-hr Time-weighted avg. IDLH= Immediately Dangerous to Life or Health Ca, * = Suspect Human Carcinogen C= Ceiling Value

3. Odor Threshold > 2 X PEL or TLV Odor indicates significant hazard

Substance Odor Threshold PEL

STEL TWA

TLV

STEL TWA

IDLH
Acrylonitrile 20 10 (C) 2 - 2* Ca
Arsine 0.2-0.6 - 0.05 - 0.05 Ca
Benzene 1.5-8.5 5 1 - 10** Ca
Bromoform 530 - 0.5 - 0.5 NA
Carbon tetrachloride 20-100 - 2 - 5* Ca
Lindane (mg/m3) 4 - 0.5 - 0.5 1000
Mercury vapor (mg/m3) None (?) - 0.05 - 0.05 30
Parathion 0.5 - 0.1 - 0.1 20
Phosgene 0.1-1 - 0.1 - 0.1 2
Toluene diisocyanate 0.2-2 0.02 0.005 0.02 0.005 10

Key : PEL= OSHA Permissible Exposure Limit TLV= ACGIH Threshold Limit Value STEL= Short Term (15-30 min) Exposure Limit

TWA= 8-hr Time-weighted avg. IDLH= Immediately Dangerous to Life or Health Ca, * = Suspect Human Carcinogen C= Ceiling Value