DG Colorimetric Indicators

The DG Colorimetric Indicators are available for wide variety of toxic gases and vapors in air. These indicators are suitable for OSHA Time Weight Average (TWA) measurements and Short-Term Exposure Limit (STEL) measurements. Uniformly coating for reproducibility and accuracy.


  • Irreversible color change
  • Real-time and direct read
  • Detection limit at or below OSHA permissible exposure limits
  • Accurate and reproducible (overall accuracy, better than ±25% at the 95% confidence level)
  • Selective to target chemical
  • long service life and shelf life
Item No.Chemical NamePart No.Minimum Detectable


Service Life


Shelf Life (Years)Cross Interferences
1Acetone (Methyl ketones Indicator)53359 months1a
2Acids5110.0714 months1b
3Ammonia5171022None known
4Allyl bromide551511h
5Aniline5130.248 hours1c
6Aromatic diisocyanates5150.00511None known
7Arsine5160.028 hours1d
8Basic vapors5120.0514 months1e
9Chlorine (Halogens Indicator)5190.29 months1Other halogens
10Chlorine dioxide (HS)5200.311Strong Oxidants
11Chlorine dioxide (LS)5441011Strong Oxidants
12Dimethyl hydrazine (-1,1) (UDMH)5220.00424 hours1f
13Ethyl chloroformates5230.0272 hours1g
14Fluorine (Halogens Indicator)5190.29 months1Other halogens
18Hydrazine (LS) Waterproof5450.1522None known
19Hydrazine (LS) Waterproof, two sides5260.1522None known
20Hydrogen chloride5270.511None known
21Hydrogen fluoride5280.511None known
22Hydrogen sulfide5290.0522None known
23Hydrogen sulfide Waterproof5460.522None known
24Hydrogen sulfide Waterproof, two sides5480.522None known
25Iodine (Halogens Indicator)5190.29 months1Other halogens
27Mercaptans553111None known
28Methyl chloroformate5320.272 hours1k
29Methyl ethyl ketone53359 months1a
30Monomethyl hydrazine5340.00448 hours1l
31Nitrogen dioxide HS5350.00511m
32Organic Vapors536n11n
33Ozone5370.0058 hours1o
34Phosgene5380.01572 hours1p
35Phosphine5390.028 hours1q
36Sulfur dioxide HS5410.28 hours1None known
37UV Light ink (irreversible)547rrrr

HS = High Sensitivity, LS = Low Sensitivity

a. Other methyl ketones

b. Basic vapors impair the acid indicator

c. Other aromatic amines react with approximately the same sensitivity. Hydrazine and monomethyl hydrazine show color formation at 8.5ppb·hr. Unsymmetrical dimethyl hydrazine shows color formation at 60ppb·hr. No other interferences are known.

d. Mercury, stibine and other hydrides.

e. Acids impair the basic vapors indicator.

f. Mono methyl hydrazine, hydrazine and aromatic amines.

g. Benzoyl chloride, carbonyl bromide, cyanuric chloride, methyl chloroformate and phosgene are known interferences. No other interferences are known.

h. Acrolein and aldehydes found in cigarette smoke react with approximately the same sensitivity. No other interferences are known.

i. Mono methyl hydrazine, dimethyl hydrazine (-1,1) (UDMH) and aromatic amines

j. Hydrides and strong oxidizers.

k. Benzoyl chloride, carbonyl bromide, cyanuric chloride, ethyl chloroformate and phosgene are known interferences. No other interferences are known.

l. Hydrazine, dimethyl hydrazine (-1,1) (UDMH) and aromatic amines.

m. Other nitrogen oxides and strong oxidizers.

m. Please contact us at info@chemteq.net

o. Hydrogen peroxide and nitrogen oxides.

p. Benzoyl chloride, carbonyl bromide, cyanuric chloride, ethyl chloroformate and methyl chloroformate are known interferences. No other interferences are known.

q. Mercury, stilbene and other hydrides.

r. Irreversible quantification of ultra violet exposure.

If you require an application not listed, please contact us at info@chemteq.net or call us at 877-CHEMTEQ

Useful Links
OSHA Permissible Exposure Limits
NIOSH Pocket Guide to Chemical Hazards

The Colorimetric Indicators are inside:

  1. Area monitors
  2. Breakthrough Indicators
  3. Breakthrough Indicator Stickers

Most of these devices are available for:

  1. Acids
  2. Allyl bromide
  3. Ammonia
  4. Ammonia & hydrogen sulfide
  5. Aromatic diisocyanates
  6. Basic vapors
  7. Chlorine dioxide
  8. Formaldehyde
  9. Glutaraldehyde
  10. Halogens
  11. Mercury & mercury II compounds
  12. Hydrazines
  13. Hydrogen sulfide
  14. Hydrogen sulfide (waterproof)
  15. Mercaptans
  16. Methyl ketones
  17. Nitrogen dioxide
  18. Organic vapors
  19. Sulfur dioxide.
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