Hydrogen sulfide, or H2S, is a hazard that can creep up on you. You cannot see it, and if the concentration is high enough, you will not even be able to smell it. This toxic gas is colorless and collects in low-lying areas. H2S is so powerful that it can kill you with one breath. It is known as “The Silent Killer.” In this chapter, we will review the safe work practices designed to protect you from hazardous exposure to H2S.

1. 1
INTRODUCTION TO
HYDROGEN SULFIDE

2. 2
Hydrogen sulfide, or H2S, is a hazard that can creep up
on you. You cannot see it, and if the concentration is high
enough, you will not even be able to smell it. This toxic
gas is colorless and collects in low-lying areas. H2S is so
powerful that it can kill you with one breath. It is known
as “The Silent Killer.” In this chapter, we will review
the safe work practices designed to protect you from
hazardous exposure to H2S.
GEAR UP

3. 3
Regulations and Responsibilities

4. Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
4
Several government agencies regulate H2S
exposure
APIANSI
NIOSH
and
ACGIH
OSHA

5. Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
5
Worker
responsibilities
Attending H2S education and training
Using controls and following safe work
practices
Using required PPE and personal
monitors
Reporting exposure incidents
Using SWA when necessary

6. Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
6
All workers must receive appropriate training
according to their level of potential exposure to
H2S

7. 7
Sources of Hydrogen Sulfide

8. 8
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
H2S is produced in nature, mainly through the
decomposition of organic material by bacteria
Natural H2S can develop within low-oxygen
environments
Bogs
Swamps
Polluted water

9. 9
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Sulfur springs
Natural gas
Petroleum and
crude oil
Sulfur depositsVolcanic gases
H2S forms
part of

10. 10
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Environments laced with H2S are known as “sour”
environments

11. 11
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Industrial Sources
At the shale
shaker area
At the
circulation
fluid
treatment
areas
During
tripping
procedures
At the
wellhead
At the cellar
Onto the
drilling floor
During oil and gas well-drilling operations, H2S can
be released
Water
injection
operations
Enhanced
recovery
operations

12. 12
Physical and Chemical Properties

13. 13
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
H2S
can be
called
Rotten egg gas
Devil’s breath
Meadow gas
Sour gas
Swamp gas Stink damp

14. 14
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Refer to the Hydrogen Sulfide Physical and
Chemical Properties table in your student
workbook for a more detailed breakdown of H2S

15. 15
Exposure

16. 16
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
You can be
exposed to
H2S through
Inhalation
Skin contact
Greatest
danger to
workers

17. 17
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
OSHA, NIOSH, and ACGIH have set exposure
limits for H2S to protect workers
Exposure limits are for air levels only
OSHA ACC: 20 ppm
NIOSH
(followed by API and ANSI)
REL: 10 ppm
IDLH: 100 ppm
ACGIH
TLV-TWA: 1 ppm
STEL: 5 ppm

18. 18
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
10 ppm is the industry accepted exposure level
Companies must notify workers of their accepted
exposure level
If the H2S concentration is at or above 100 ppm
It is IDLH
You need special PPE

19. 19
Health Effects

20. 20
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Body mass
Overall physical condition
Age
Personal biochemistry
Wearing contact lenses
You may be more
at risk or
sensitive to the
effects of H2S
because of your

21. 21
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
You may also be more sensitive to the effects
of H2S if you
These substances are toxins that your liver normally
filters out of your body
Smoke cigarettes, drink alcohol, or take
prescription medication or illicit drugs

22. 22
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Your liver has to work harder to
clean your blood
Allows toxins to
linger
Worsens the effects
of H2S

23. 23
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Other factors that affect your reaction to H2S
include the exposure
DurationFrequencyConcentration

24. 24
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
When you inhale H2S, the
chemical affects your
Eyes
Nose
Brain
Lungs
Nerve pathways
Optic nerve
Olfactory
nerve
Vagus
nerve

25. 25
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
At high concentrations, H2S impairs and even
temporarily eliminates your sense of smell
Do not rely on odor as your only
warning to the presence of H2S

26. 26
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Health Effects of Exposure to Hydrogen Sulfide
1 ppm Can smell H2S
10 ppm Headaches, dizziness, nausea and vomiting,
coughing, difficulty breathing
20 ppm Irritated, inflamed eyes and irritated
airways after 1 hour of exposure
50 ppm  Sense of smell eliminated after 15 minutes or more of exposure
100 ppm  Loss of sense of smell after 3
minutes
 Respiratory tract and eye
irritation
200 ppm  Sense of smell eliminated
almost instantly  Burning eyes and nose
500 ppm  Unconscious after brief
exposure
 Not able to breathe if not
treated quickly
700 ppm  Unconscious almost
instantly
 Breathing
stopped Will die if not rescued
1,000 ppm  Instant unconsciousness  Permanent brain damage or
death

27. 27
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Exposure to a high concentration over
a short period of time; the result of a
single dose or exposure to a
substance
Acute
effects
Exposure to low concentrations
over a long period of time
Chronic
effects

28. 28
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Chronic Toxicity
Low blood pressure
Loss of appetite
Weight loss
Chronic cough
Neurological symptoms, including
psychological disorders
Symptoms
of chronic
exposure can
include

29. 29
Communicating the Hazards of
Hydrogen Sulfide

30. 30
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
All well-drilling
sites should be
classified
according to
areas of
potential or
actual exposure
to H2S

31. 31
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Warning Signs and Alarms
API classifications for H2S areas
API Condition I – Low Hazard
No Hazard Condition
API Condition II – Medium Hazard
API Condition III – High Hazard
No amounts of
H2S
Less than 10
ppm
10-30 ppm
Greater than
30 ppm

32. 32
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Different alarms should be set to indicate
the levels of H2S
Warning Signs and Alarms
Alarms you can see and hear must be set up
around H2S areas

33. 33
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Warning Signs and Alarms
Alarm Settings
Alarm Level H2S Concentration Warning Signal
On Land
Low alarm 10 ppm Flashing amber light
High alarm 20 ppm Intermittent siren
Offshore
Low alarm 10 ppm Flashing amber light
High alarm 20 ppm
Intermittent siren and
flashing red light
Very high alarm 50 ppm
Continuous siren and
flashing amber and red light

34. 34
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Warning Signs and Alarms
When you see flashing lights or hear an alarm
Leave the area immediately unless you are trained
and authorized to deal with an H2S emergency

35. 35
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Engineering Controls
Keep H2S exposure as low as possible and
can include
Ventilation and monitoring equipment
Design, remodel, or enclose worksites
Metallurgical properties of equipment
Burning, flaring, and venting
Using intrinsically safe electrical systems
Containment and dispersion
Using non-sparking, corrosion-resistant ventilation systems

36. 36
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Burning and Flaring
May be used when H2S could
be present in concentrations
over 15 ppm
Burns off H2S to prevent it
from collecting in the work
area

37. 37
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Burning and Flaring
Produces SO2
Irritating toxic gas
Colorless
Has a burned match
odor

38. 38
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Burning and Flaring
Brain CNS Kidneys
SO2 affects your

39. 39
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Using SWA
Performing JSAs
Controlling ignition sources
Performing ventilation and air monitoring
Keeping non-essential workers away from the area
Making sure all required permits are used and are
compliant
Using non-sparking tools and approved explosion-
proof equipment
Administrative Controls
Your company should make sure all workers use safe
work practices such as

40. 40
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Administrative Controls
Use the buddy system when working in H2S
areas
Workers are paired off so they can look out for
one another
Make sure you maintain contact with your
buddy
Know where they are at all times

41. 41
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Administrative Controls
Wind conditions tell you which way H2S will
spread
Check the wind sock or streamer regularly
Stay aware of wind conditions at all times

42. 42
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Administrative Controls
Whenever possible, start on
the upwind side when working
on equipment
Make sure you are not
downwind of an H2S source
Have an escape route and know
where exits are in case you have
to get out immediately

43. 43
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Administrative Controls
If you notice
the smell of
H2S or hear
an alarm
1
2
3

44. Source of H2S Wind Direction
Concentration
decreases from
center
Concentration
decreases away
from source
YOU
GO CROSSWIND AND UPWIND!
Which way do you go?

45. 45
Detection and Monitoring
Methods

46. 46
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Here are the readings, in ppm, at which you
would detect the presence of H2S
H2S Concentration Odor
0.13 ppm Minimal perceptible odor
0.77 ppm Faint but perceptible odor
4.6 ppm Easily detectable, moderate odor
27 ppm Strong, unpleasant odor
28-100 ppm
Rotten egg odor or sweet, acetone-
like odor

47. 47
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Companies must test your work area regularly
for H2S
Air monitoring must be performed before each
job and continuously while workers are in the
area

48. 48
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Your company may use several different types
of monitors for air monitoring, including
Only workers who have been specifically trained
in how to use an H2S monitor can use one
Fixed monitors
Personal monitors
Portable monitors

49. 49
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Monitor Service and Calibration
All H2S monitors
must be
Serviced and tested
according to
manufacturer
recommendations
Kept clean and dry
Calibrated at least
every 3 months

50. 50
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Fixed Monitors
Continuously monitor H2S
concentrations in key areas
where
Workers are likely to be
present
H2S may be released or
accumulate

51. 51
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Fixed Monitors
On offshore sites
Monitors must be set up within 10 ft. of equipment that
could release H2S

52. 52
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Personal Monitors
Take in samples of the
air a worker is
breathing
Worn in areas where
the H2S concentration
could exceed 10 ppm

53. 53
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Personal Monitors
Position the air intake point in
your breathing zone
In front of your face and
shoulders
6-9 in. radius that centers on
your nose
Check with your company for its requirements on
wearing personal monitors

54. 54
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Portable Monitors
Portable
monitors, also
known as gas
detectors, are
designed to be
placed
Between workers and
the source of H2S
Inside a confined
space

55. 55
Using a Gas Detector

56. 56
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
It is your responsibility to monitor
potentially hazardous atmospheres
before you enter to determine if
there are hazardous gases present
As a
worker

57. 57
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Gas detectors are used to
identify atmospheric
hazards
Gas testing must be done
by someone knowledgeable
in the use of the instrument
and familiar with the space

58. 58
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
If a multi-gas detector is not being used, the
atmosphere must be tested in the following order
Suspected toxic gases – carbon monoxide
and H2S
Oxygen
Lower explosive limit (flammable and
combustible gases)
1
2
3

59. 59
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Compare your readings to the acceptable entry
conditions shown in the Monitoring for
Potentially Hazardous Atmospheres chart
Atmospheric Condition Acceptable Entry
Oxygen 19.5% to 23.5%
LEL (combustible gas) 0% to 10%
Carbon monoxide 0 ppm to 25 ppm
H2S 0 ppm to 10 ppm

60. 60
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
If you find hazardous atmospheric
conditions
Do not allow anyone to enter
the area until it has been
declared safe for entry

61. 61
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Gas Detector Operation
Be sure you are familiar
with the make and model
of the gas detector you
will use
Read the user manual
before you use a gas
detector

62. 62
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Gas Detector Operation
Because certain gases
rest at different levels
within the space, take
readings from various
locations
Bottom
Top
Middle

63. 63
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Gas Detector Operation
Gases will settle according
to their vapor density
How gases settle changes
with environmental
conditions like
Temperature
Pressure

64. 64
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Gas Detector Operation
Even if these tests are
successful
Conduct a bump test to verify that
each sensor is working correctly

65. 65
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Bump Testing
Makes sure a gas detector’s
alarms and sensors are working
properly
Exposes the gas detector to a set
concentration of gases that
exceeds the lowest alarm setting
for each sensor
Verifies that all sensors are in
good working condition

66. 66
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Bump Testing
Make sure you are in a clean environment when
performing a bump test
All bump tests must be performed according to
manufacturer instructions

67. 67
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Bump Testing
The basic steps to perform a bump test are
Attach the tubing to the calibration fitting
Attach the proper flow-per-minute regulator to the cylinder
Have an approved calibration gas cylinder
Turn on the gas detector using the normal startup procedure
1
2
4
3
Open the regulator to apply calibration gas to the gas
detector5

68. 68
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Bump Testing
They do not
confirm the
accuracy of
readings
While bump tests
confirm that sensors
and alarms are
working properly
Gas detectors must be
properly calibrated
to determine the
accuracy of readings

69. 69
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Calibration
Exposing a gas detector’s sensors to
known concentrations of calibration
gases to make sure the detector
readings are accurate
Calibration

70. 70
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Calibration
Replace the
sensors

71. 71
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Document the calibration on the log
Follow the instructions on the screen to set calibration
dates and save the calibration
Apply the calibration gas
Allow the gas to cycle through the detector until it tells
you the calibration was successful
5
6
8
7
Calibration
The basic steps to calibrate a gas detector are
Connect the regulator and the calibration adapter using
the tubing
Connect the regulator to the calibration cylinder
Turn on the gas detector using the normal startup
procedure
Activate the gas detector’s calibration feature
1
2
4
3

72. 72
Respirator Use

73. 73
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Respirators must be
worn whenever H2S
levels are not kept below
exposure limits

74. 74
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
SARs must be worn
in work areas
contaminated with
H2S concentrations
over 10 ppm or
their company’s
action level

75. 75
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
In environments with more than 10 ppm of
H2S or more than 2 ppm of SO2, wear
one of the following
Positive-pressure, full-
facepiece hoseline/airline
SAR and carry an escape
pack
Positive-pressure SCBA

76. 76
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Offshore workers must
use at least two
voice-transmission
devices while wearing
a respirator

77. 77
Hydrogen Sulfide in Confined
Spaces

78. 78
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
A confined space is a space that
Is large enough
for a worker to
enter
Has limited or
restricted entry
or exit
Is not meant to
be occupied for
a long amount of
time

79. 79
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Safety measures for H2S in confined space
work include
Obtaining a confined space permit
Conducting air monitoring before entry
Ventilating the space before entry
Continuously monitoring the air while
workers are in the confined space
Being trained on procedures that relate to
H2S and confined spaces
Being trained on emergency rescue
procedures
Venting or purging lines on vessels before
beginning work

80. 80
Emergency Response

81. 81
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Workers should participate in drills that
simulate an H2S emergency so they can
Practice performing their duties
Enhance emergency planning
and readiness

82. 82
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Drills should be realistic simulations where
Equipment is
deployed
Communication
gear is tested
Workers role-
play as rescuers
and victims

83. 83
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Should be revised and retested
until those responsible for the plan
are confident it works
Contingency
plans

84. 84
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Contingency Plans
All workers must know the location of
Give workers a step-by-step
guide for handling emergencies
Company
contingency
plans
Contingency
plans
Assembly
points
(muster areas)
Emergency
equipment

85. 85
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Contingency Plans
You must know and follow
Rescue operations
Emergency shutdown procedures
Notification procedures

86. 86
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Immediate Action Plans
The immediate action plan for H2S is
Account for all workers
Go to your company’s emergency assembly point
Stop breathing; either purge then don your emergency-use
respirator or escape pack if it is available, or move away
from the source and get out of the affected area
Alert other potentially affected workers
1
2
4
3

87. 87
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Rescue
Only rescue a victim if
you have been trained
to do so and you have
the proper PPE
You must protect
yourself first before
you can rescue
someone else

88. 88
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Rescue
Companies must train
workers in site-specific
rescue techniques
If you are going to
perform a rescue, tell
your coworkers first so
they know what is going
on

89. 89
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
First Aid
EMS must be activated as quickly as possible for
a victim to survive
At least one worker must know
Rescue techniques
How to give first aid to H2S and SO2 victims

90. 90
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Post-exposure Medical Evaluation
Victims of H2S inhalation are in danger of
developing medical complications for some time after
rescue
Some delayed symptoms include
Pulmonary edema Dizziness
Photophobia Nausea

91. 91
Regulations and
Responsibilities
Sources of Hydrogen
Sulfide
Physical and
Chemical Properties
Exposure
Health Effects
Communicating the
Hazards of
Hydrogen Sulfide
Detection and
Monitoring Methods
Using a Gas
Detector
Respirator Use
Hydrogen Sulfide in
Confined Spaces
Emergency Response
Individuals who have recovered and wish to
return to work must first receive medical
clearance

92. 92
H2S is an invisible hazard. To work safely in areas of
potential exposure, you must be aware of your role,
understand the controls that are in place, and follow
any policies and procedures required by an operator or
your company. You must receive training on planning,
selecting equipment and materials, and operation and
emergency procedures. Commitment to H2S safety is
essential for the well-being of everyone on the worksite.
PROTECT YOURSELF

93. 233 General Patton Ave. Mandeville, LA 70471 | 1.800.892.8179 | www.pecsafety.com