HETA 96–0138–2691

Torch Operating Company

Santa Maria, California

Dino A. Mattorano

Timothy Merinar

This Health Hazard Evaluation (HHE) report and any recommendations made herein are for the specific facility evaluated and may not be universally

applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.

Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports

This Health Hazard Evaluation (HHE) report and any recommendations made herein are for the specific facility evaluated and may not be universally

applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.

Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports

This Health Hazard Evaluation (HHE) report and any recommendations made herein are for the specific facility evaluated and may not be universally

applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.

applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.

Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports
ii

PREFACE

The Hazard Evaluations and Technical Assistance Branch of NIOSH conducts field investigations of possible

health hazards in the workplace. These investigations are conducted under the authority of Section 20(a)(6)

of the Occupational Safety and Health Act of 1970, 29 U.S.C. 669(a)(6) which authorizes the Secretary of

Health and Human Services, following a written request from any employer or authorized representative of

employees, to determine whether any substance normally found in the place of employment has potentially

toxic effects in such concentrations as used or found.

The Hazard Evaluations and Technical Assistance Branch also provides, upon request, technical and

consultative assistance to Federal, State, and local agencies; labor; industry; and other groups or individuals

to control occupational health hazards and to prevent related trauma and disease. Mention of company names

or products does not constitute endorsement by the National Institute for Occupational Safety and Health.

ACKNOWLEDGMENTS AND AVAILABILITY OF REPORT

This report was prepared by Dino A. Mattorano, of the Hazard Evaluations and Technical Assistance Branch,

Division of Surveillance, Hazard Evaluations and Field Studies (DSHEFS). Field assistance was provided

by Timothy Merinar, of the Certification and Quality Assurance Branch, Division of Respiratory Disease

Studies. Desktop publishing by Nichole Herbert. Review and preparation for printing was performed by

Penny Arthur.

Copies of this report have been sent to the Mineral Management Services and the OSHA Regional Office.

This report is not copyrighted and may be freely reproduced. Single copies of this report will be available

for a period of three years from the date of this report. To expedite your request, include a self–addressed

mailing label along with your written request to:

NIOSH Publications Office

4676 Columbia Parkway

Cincinnati, Ohio 45226

800–356–4674

After this time, copies may be purchased from the National Technical Information Service (NTIS) at

5825 Port Royal Road, Springfield, Virginia 22161. Information regarding the NTIS stock number may be

obtained from the NIOSH Publications Office at the Cincinnati address.

For the purpose of informing affected employees, copies of this report shall be

posted by the employer in a prominent place accessible to the employees for a

period of 30 calendar days.
iii

Health Hazard Evaluation Report 96–0138–2691

Torch Operating Company

Santa Maria, California

May 1998

Dino A. Mattorano

Timothy Merinar

SUMMARY

The National Institute for Occupational Safety and Health (NIOSH) received a request for technical assistance

from the Department of the Interior, Mineral Management Services (MMS), located in Santa Maria, California.

According to the request, inspectors of Offshore Operations and Safety were concerned about respiratory

protection against hydrogen sulfide (H2S). Specific concerns were with the Robertshaw (air capsule) 5–minute,

hooded, continuous–flow, escape self-contained breathing apparatus (ESCBA) and the general use of hooded

ESCBAs. 

 On August 11 and 12, 1996, NIOSH investigators conducted a site visit on platform “Irene,” an offshore drilling

rig owned and operated by Torch Operating Company (TOC). Platform Irene is located on the Outer Continental

Shelf of the Pacific Ocean, 5–7 miles off the coast of Santa Maria, California. It is designed to support both drilling

and production operations. At the time of the NIOSH site visit, platform Irene was in the production phase and

accommodated 15 workers.

The site visit began with a walk–through inspection of the platform to become familiar with the layout, to identify

respirator equipment locations and safe briefing areas, and to observe various job tasks and locations. On the

second day, the Whittaker escape pods were observed and a drill was simulated so NIOSH investigators could

observe platform workers don respirator equipment and escape to a safe briefing area. 

Based on the information obtained during the NIOSH site visit, hooded, continuous flow, ESCBAs should

not be used on offshore platforms; they can be over–breathed, do not have airline capabilities, and the

user’s vision can be impaired. Although a respiratory protection program was in place, deficiencies (lack

of a written program and respirator fit testing) were identified. Recommendations are made to replace

hooded, continuous flow, ESCBAs with pressure demand, full facepiece, SCBAs, and to improve the

respiratory protection program by designing a comprehensive written program which includes quantitative

respirator fit testing.

Keywords: SIC 1311 (Crude Petroleum and Natural Gas) offshore drilling rig, offshore platform, hydrogen

sulfide, oil and gas production, escape self-contained breathing apparatus (ESCBA), self contained breathing

apparatus (SCBA), Whittaker escape pod, mineral management services. 
TABLE OF CONTENTS

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii

Acknowledgments and Availability of Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

Introduction ......................................................................... 2

Background ......................................................................... 2

Evaluation Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Respiratory Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Discussion/Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Page 2 Health Hazard Evaluation Report No. 96–0138

INTRODUCTION

The National Institute for Occupational Safety and

Health (NIOSH) received a request for technical

assistance from the Department of the Interior,

Mineral Management Services (MMS), located in

Santa Maria, California. According to the request,

inspectors of offshore operations and safety were

concerned about appropriate respiratory protection

against hydrogen sulfide (H2S). Specific concerns

were with the adequacy of Robertshaw (air capsule)

5–minute, hooded, continuous–flow, escape

self–contained breathing apparatus (ESCBA) and the

general use of hooded ESCBAs.

On August 11 and 12, 1996, NIOSH investigators

conducted a site visit on platform “Irene,” an

offshore drilling rig owned and operated by Torch

Operating Company (TOC). Prior to the site visit,

NIOSH investigators were given mandatory H2S

training and experience with respirator donning

procedures. The training was provided by Secorp

Industrials, a contract company which also

maintained the respirator equipment, respiratory

protection program, and the H2S monitoring

equipment. Upon completing H2S training, NIOSH

investigators, accompanied by representatives from

TOC, Secorp, and MMS, conducted a walk–through

survey of the platform to become familiar with the

layout, to identify respirator equipment locations and

safe briefing areas, and to observe various job tasks

and locations. 

BACKGROUND

Platform Irene is located on the Outer Continental

Shelf of the Pacific Ocean, 5–7 miles off the coast of

Santa Maria, California. The platform is

approximately 400 feet high (250 feet below water

and 150 above water) and has three decks above

water: the drilling deck (83 feet above the water with

dimensions of 150 feet by 150 feet), the production

deck (56 feet above the water and similar dimensions

to the drilling deck), and the sub deck (41 feet above

the water and much smaller than the other decks).

The platform produces an average of 70,000 barrels

of emulsion (20% oil and 80% water) per day and

4.3 million cubic feet of gas per day. The oil portion

is sour crude oil which contains high levels of H2S.

The average H2S concentration in the pipeline is

approximately 8500 parts per million (ppm).

Offshore drilling rigs operate in various phases

including exploration, drilling, and production.

Platform Irene is designed to support both drilling

and production operations. During simultaneous

operations, platform Irene employees 50–60 workers

(30–40 on the drilling deck and 15–20 on the

production deck). During the production phase,

there are 15–20 workers on the production deck. At

the time of the NIOSH site visit, platform Irene was

in the production phase. During production, crude

oil and gas, along with contaminants (i.e., H2S and

saltwater) are produced from the oil reserve below

the surface of the ocean floor and processed on the

platform (separate gas and oil/water). The crude oil,

along with production water, is then piped to shore

for further processing. Gas is compressed for

transportation (through pipe) to the shore for

processing. 

According to representatives from MMS and TOC,

an H2S release on the production deck is mostly from

maintenance work on piping, storage tanks,

compressors, etc., or leaks in the compressors, well

heads (well room), and production/storage tanks. On

the drilling deck, an H2S release can be from the mud

pit, shaker pit, drilling platform (bell and nipple), or

a blow–out, which occurs when the bottom hole

pressure (from oil and gas reserve) is greater than the

column pressure (from drilling mud and/or gas) and

the drilling mud, oil, and gas are forced upward

toward the platform under tremendous pressure. In

most cases, blow–out preventers will stop the

fluid/gas mixture from reaching the platform. 

On platform Irene, ambient H2S concentrations are

monitored with continuous direct–reading

instruments. The fixed H2S sensors are strategically

placed throughout the platform with emphasis in

those areas where an H2S release is most likely to

occur. In the event of an H2S release that results in
Health Hazard Evaluation Report No. 96–0138 Page 3

an ambient air concentration of 10 ppm or more at

any given H2S sensor, an audible alarm will sound

throughout the platform and a visual alarm (amber

light) will flash at the specific activated H2S sensor.

A person in the control room will inform all

personnel, via PA system, of the location of the

alarm. At that point, all personnel are to note the

nearest ESCBA. If ambient air concentrations reach

or exceed 20 ppm, the audible alarm will sound

platform–wide, but the visual alarm will change to a

flashing red light. A person in the control room will

inform all personnel of the location of the H2S alarm,

to what safe briefing area they should go (usually

safe briefing area upwind of H2S release), and what

route should be taken. At that point, all essential

personnel designated to address the H2S release are

to assemble at the production deck fire locker, don

the appropriate personal protective equipment, and

wait for instructions from the supervisor in charge.

All other personnel are to secure ESCBAs, proceed

to the designated safe briefing area, and await

instructions. Portable direct reading H2S monitors

are located at each safe briefing area to monitor

ambient air concentrations. 

The platform is equipped with two blowers which

can be used to create air movement if the wind is

calm. If the platform should be abandoned because

H2S concentrations in the safe briefing area and

living quarters reach or exceed 10 ppm, all

non–essential personnel will board the platform

escape pod (Whittaker capsule) and await

instructions. If H2S concentrations around the

Whittaker reach or exceed 10 ppm, the Whittaker is

sealed and its cascade air system activated. The

Whittaker is then lowered to the ocean and moved

upwind of the platform. Essential personnel not only

address the H2S release, but also deploy visual signs

to alert helicopter and water craft in the immediate

vicinity of the platform, and notify various agencies

(MMS, United States Coast Guard, and medical

facilities) of the H2S release. If essential personnel

must abandon the platform, a second Whittaker

capsule is available. It should be noted that the

activities described above regarding an H2S release

are very general and do not include all duties that

essential and non–essential personnel may perform.

Only information pertinent to the NIOSH

investigation is discussed. 

Minor localized H2S releases that require workers to

escape to safe briefing areas generally occur one to

two times per year. The last H2S release on platform

Irene occurred approximately 18 months prior to the

NIOSH site visit. Platform workers were

repairing/replacing a section of pipe. After purging

the pipe of airborne contaminants (i.e., H2S), workers

began cutting the pipe. Because the pipe was

partially obstructed, all contaminants were not

purged, which resulted in a localized H2S release.

Major H2S releases or blow–outs are events that

occur infrequently. To date, no major H2S releases

or blow–outs have occurred on platform Irene. The

last major H2S release in the MMS Santa Maria

District occurred several years ago. During the

beginning stage of drilling a new well, the operator

drilled into an existing closed well, containing

compressed gas, about 1000 feet below the surface of

the ocean. Because the new well was so shallow, the

blow–out preventer did not have time to respond

resulting in a release of gas, water, drilling mud, and

H2S. However, workers were not exposed to H2S

because the mixture was diverted overboard and

downwind of the platform. Prior to this, the last

blow–out in the Pacific Outer Continental Shelf

Region was in 1969. 

EVALUATION CRITERIA

H2S is a colorless, flammable gas with a strong odor

of rotten eggs. It can be encountered in the

production and processing of gas and crude oil.

Acute exposure to H2S at airborne concentrations

above 10 ppm has been associated with the

development of conjunctivitis and keratitis.1

 One

hour exposure to H2S concentrations between 50 and

100 ppm can produce mild eye and respiratory

irritation which becomes markedly worse when the

concentrations are in the 200 to 300 ppm range. At

H2S concentrations between 500 and 700 ppm,

exposures for 0.5– to 1–hour can result in

unconsciousness and death, and between 1000 to

2000 ppm or more, unconsciousness and death can
Page 4 Health Hazard Evaluation Report No. 96–0138

occur within minutes. Conclusive evidence of

adverse health effects from chronic exposure to H2S

at concentrations below 20 ppm is lacking.1,2,3,4

However, there is some evidence that H2S alone at

low concentrations, or in combination with other

chemical substances (e.g. petroleum products or

carbon disulfide), is associated with the development

of nervous system, cardiovascular, and

gastrointestinal disorders, and it affects the eyes.

Repeated exposure to H2S results in increased

susceptibility, so that eye irritation, cough, and

systemic effects may result from concentrations

previously tolerated without effect. H2S has an odor

threshold between 0.002 and 0.003 ppm for humans.3

The smell is faint, but easily perceptible at 0.77 ppm

and offensive at 3 to 5 ppm. Up to about 30 ppm,

H2S smells of rotten eggs, but at about 30 ppm the

smell is described as sweet or sickening sweet. At

150 ppm, H2S causes olfactory–nerve paralysis and

the smell is no longer perceptible. The smell of H2S

therefore is not a reliable warning of its presence,

especially at high concentrations. 

In a recent study, Bhambhani, et al.5

 compared the

effects of inhalation of 5 ppm H2S on the

physiological and hematological responses of

healthy men and women during exercise. Subjects

included in the study completed two 30–minute

exercise tests on a cycle ergometer at 50% of their

predetermined maximal aerobic power while

breathing medical air or 5 ppm H2S from a specially

designed flow system. The results indicated that

there were no significant differences between the

two exposures for the metabolic (oxygen uptake,

carbon dioxide production, respiratory exchange

ratio), cardiovascular (heart rate, blood pressure, rate

pressure production), arterial blood (oxygen and

carbon dioxide tensions, pH), or perceptual (rating of

perceived exertion) responses in either sex. None of

the subjects reported any adverse health effects

subsequent to the H2S exposure. These results

suggest that healthy men and women can safely

perform moderate intensity work in environments

contaminated with 5 ppm H2S or lower. The device

used to deliver H2S to the subjects fits in their

mouths and did not result in exposure to the subjects'

eyes. This is important since adverse effects on the

eyes are what NIOSH and the Occupational Safety

and Health Administration (OSHA) exposure limits

are based on.

The NIOSH REL for H2S is a 10–minute ceiling

concentration of 10 ppm.6

 When there is a potential

for exposure to H2S at a concentration of 50 ppm or

higher, continuous monitoring is recommended by

NIOSH. The OSHA standard for H2S is a 10–minute

ceiling concentration of 20 ppm or a maximum

allowable peak of 50 ppm for 10–minutes once, if no

other measurable exposures occur.7

 The American

Conference of Governmental Industrial Hygienists

(ACGIH®) recommends a threshold limit value

(TLV®) of 10 ppm as a 8–hour time–weighted

average (TWA) and a short–term exposure limit

(STEL) of 15 ppm.8

RESPIRATORY

PROTECTION

Under Code of Federal Regulation (CFR) 30 part

250.67 (Hydrogen sulfide),9

 the MMS requires that

when exploring or developing zones classified as

H2S present or H2S unknown:

all personnel, including contractors and visitors on

a facility, must be provided with immediate access to

pressure–demand–type (PD) respirators with

hoseline capability and breathing time of at least

15 minutes. Design, select, use, and maintain

respirators to conform to American National

Standard Institute (ANSI) Z88.2, Practices for

Respiratory Protection. 

The American Petroleum Institute (API) has written

a standard with respect to oil and/or gas producing

and gas processing facilities. Recommended practice

number 55 (RP55), Recommended Practices for Oil

and Gas Producing and Gas Processing Plant

Operations Involving Hydrogen Sulfide,10 requires:

site specific contingency plans shall be prepared to

specify the quantity and location of breathing

equipment to be available. Respirators shall meet
Health Hazard Evaluation Report No. 96–0138 Page 5

the requirements of the Occupational Safety and

Health Administration’s Respiratory Protection

Standard (29 CFR Part 1910.134) and be approved

under procedures outlined in ANSI Z88.2. The

following types of breathing equipment with full

facepiece meet these requirements and should be

used where the work area atmospheric concentration

exceeds 10 parts per million (ppm) for hydrogen

sulfide or 2 ppm for sulfur dioxide: 

A. Self–contained, positive-pressure/pressuredemand breathing equipment that provides

respiratory protection in any atmospheric

concentration of hydrogen sulfide or sulfur dioxide.

B. Positive–pressure/pressure–demand air–line

breathing equipment coupled with a self contained

breathing apparatus (SCBA) equipped with a low

pressure warning alarm and rated for 15 minutes

(minimum). This equipment permits the wearer to

move from one work area to another.

C. Positive–pressure/pressure–demand, air–line

breathing equipment, with auxiliary self–contained

air supply (rated for a minimum of 5 minutes). This

type of unit can be used for entry as long as the air

line is connected to a source of breathing air. The

auxiliary self–contained air supply (rated for less

than 15 minutes) is suitable only for escape or

self–rescue use.

In addition to the required PD–type SCBAs, MMS

has allowed offshore platforms to use hooded

ESCBA respirators for emergency escape to safe

briefing areas. In the event of an H2S release, all

personnel considered essential (address H2S release)

must don personal protective equipment required to

enter into H2S contaminated areas, i.e., PD–type

SCBAs with airline capability. On platform Irene,

like many large Outer Continental Shelf facilities, the

workforce includes personnel that are employed

temporarily under contract. In the event of an H2S

release, only a portion of the personnel are

considered essential when addressing an H2S release.

The remaining non–essential personnel are to

proceed directly to the designated safe briefing area.

Because of the increased size of the platforms, the

increased number of non– essential personnel, and

the fact that personnel do not work in one specific

area, MMS feels that one respirator per person may

not be protective enough and allows the use of

hooded ESCBAs to escape to safe briefing areas.

Furthermore, contract workers may only be on the

platform for a few days and the simplicity of the

hooded ESCBAs is advantageous. By allowing

companies to utilize hooded ESCBAs, the

distribution of respirator protection on the platform

is increased. Lastly, hooded ESCBAs can be used on

a platform as long as the quantity, location, and

specific use of all breathing equipment are described

in the H2S Contingency Plan and approved by MMS.

RESULTS

On the day of the NIOSH site visit, there were

15 workers on platform Irene. Most job tasks and

activities were performed on the production deck

since the platform was in production phase.

Platform operations continue 24 hours a day with

work shifts consisting of seven consecutive 12–hour

workdays (stay on platform) followed by seven days

off (flown to shore via helicopter). 

Concerns expressed in the request were with the use

of the air capsule (coil reservoirs) 5–minute, hooded,

continuous–flow, ESCBAs on platform Irene and the

general use of hooded ESCBAs on offshore drilling

rigs. According to MMS inspectors, deficiencies

identified with the air capsule respirators included a

low air flow rate (breathing air supplied to the hood)

ranging from 17 to 25 liters per minute (Lpm),

various leaks in the air capsule coils, no airline

hookup, and a service life of 5–minutes or less (due

to leaks). At the time of the NIOSH site visit, TOC

was in the process of removing these ESCBAs from

the drill and production decks and replacing them

with other hooded continuous flow ESCBAs (with a

flow rate of 40 Lpm) and PD–type ESCBAs. Since

the air capsule ESCBAs were no longer in use on

platform Irene, NIOSH did not evaluate them. 

The respirator distribution points on platform Irene

are identified in Figures 1 and 2. On the production
Page 6 Health Hazard Evaluation Report No. 96–0138

deck, there were 45 SCBAs including 12 full

facepiece (FF), PD–type, ESCBAs with airline

capabilities and a service life of five minutes

(5–min., FF, PD, ESCBAs); 8 full facepiece,

PD–type, SCBAs with airline capabilities and a

service life of thirty minutes (30–min. FF, PD,

SCBAs); and 25 hooded (HH), continuous–flow

(CF), ESCBAs with a service life of ten minutes

(10–min. HH, CF, ESCBAs). The distribution of

respirators was such that the 10–min. hooded

ESCBAs were placed throughout the production

deck and immediately available for workers to don

and escape to the designated safe briefing area in the

event of an H2S release. Most 5–min. ESCBAs were

centrally located at safe briefing area # 2 and were

available for those workers who did not secure a

10–min. hooded ESCBA while escaping to the safe

briefing area or who ran out of air with the 10–min.

hooded ESCBA. It should be noted that hooded

ESCBAs (approved by NIOSH) do not have airline

capabilities; therefore, if a worker runs out of

breathing air with a hooded ESCBA, then the worker

must don another respirator or board the Whittaker

escape capsule. Most 30–min. SCBAs were located

in the fire locker, near change room, where essential

personnel assemble in the event of an H2S release.

Other 30–min. SCBAs were located in the control

room. On the drill deck, there were 41 SCBAs

including 27 – 5 min., FF, PD, ESCBAs; 10 – 30

min. FF, PD, SCBAs; and 4 – 10 min. HH, CF,

ESCBAs. Most respirators on the drill deck were

located in the living quarters and safe briefing area

#1. All respirators were stored in either a hard

plastic case or a sealed plastic bag.

The cascade air system, breathing air manifolds,

air–supply lines, and detachable couplings were

inspected during the NIOSH site visit. There were

five cascade air systems on platform Irene which

served a total of 16 breathing air manifolds. Each

cascade air system had eight cylinders with a total air

volume of 2400 cubic feet (300 cubic feet per

cylinder). Breathing air manifolds were located at

various sites throughout the platform (Figures 1 and

2). Each manifold was able to support five airlines.

During the walk–through survey, NIOSH

investigators found that most manifolds on the

production floor had at least two airlines except in

the safe briefing areas where the manifolds had five

air–lines. It should be noted that each safe briefing

area had only one breathing air manifold and,

therefore, only five workers would be able to hookup

to the breathing air manifold. Two high pressure

breathing air compressors, one at each safe briefing

area, were used to fill all cascade air systems,

including those in the Whittakers, and to refill all

SCBAs and ESCBAs.

Respiratory protection on the platform was

manufactured by several different companies.

Airlines and detachable couplings were the same

throughout the platform and compatible with SCBAs

and ESCBAs that had airline capabilities. However,

the airlines and detachable couplings were not

manufactured by the same company as the

respirators. 

On the platform, two escape Whittakers, one at each

safe briefing area, were used to evacuate the

platform. Each Whittaker was capable of

accommodating 50 individuals. According to TOC,

breathing air was supplied to the Whittaker by two

different air systems. As long as the Whittaker

remained attached to the platform and was not

lowered from the boarding deck, a cascade system on

the platform was used to purge the Whittaker of air

contaminates and supply approximately 30 minutes

of breathing air for 50 individuals. If the Whittaker

was lowered from the boarding deck, the cascade

system in the Whittaker was manually activated and

would provide enough air to maintain positive

pressure inside the escape pod and ensure

approximately 10 minutes of engine operation while

sustaining personnel breathing requirements. Once

launched, the Whittaker captain would maneuver the

escape pod upwind or crosswind of the platform to

insure reaching an uncontaminated atmosphere.

Currently, there are no design specifications for

breathing air systems or minimum standards for

breathing air supply for the Whittaker escape pods.

NIOSH investigators observed a simulated drill

where workers escaped to a safe briefing area. Two

individuals (platform worker and safety coordinator)
Health Hazard Evaluation Report No. 96–0138 Page 7

volunteered to perform the simulation. Both men

were between 35–45 years old, approximately

six feet tall and weighed over 200 pounds. The

simulation consisted of donning an ESCBA near the

gas skid (southeast corner of production deck) and

escaping to safe briefing area #1 (northwest corner of

the drill deck) via the center corridor of the

production deck and finally up the northwest stairs.

This route was chosen because it is most likely the

longest distance non–essential personnel would have

to travel to reach a safe briefing area. During the

simulation, the platform worker donned a 5–min.,

FF, PD, ESCBA, and the safety coordinator donned

a 10–min. HH, CF, ESCBA. 

During the simulation several noteworthy conditions

were observed. To don the respirators and escape to

the primary safe briefing area, it took the workers

approximately 48 seconds. Workers did not run

during the simulation but moved at a pace between a

brisk walk and a jog. When both men reached the

safe briefing area, NIOSH investigators observed the

safety coordinator’s hooded ESCBA slightly

inflating/deflating with each breath. This was likely

a result of over–breathing (air consumption rate

greater than the ESCBA air supply rate of 40 Lpm)

in the hooded respirator. Also, vision, which was

already distorted because of the polyurethane hood,

was further distorted because of fogging (moisture in

exhaled breath) and the continuous

inflation/deflation of the hood. The 5–min., FF, PD,

ESCBA donned by the platform workers appeared to

perform well during the simulation but, as with the

hooded respirator, the full facepiece was slightly

fogged. 

Initial observations of the ESCBAs revealed that the

platform worker used approximately 50% of the

breathing air in the 5 min., FF, PD, ESCBA and the

safety coordinator used approximately 25% of the

breathing air in the 10 min. HH, CF, ESCBA during

the 48 second drill. However, when reviewing the

video tape, it was found that, although the H2S

simulation lasted 48 seconds, the workers kept the

respirators donned for one minute and thirty seconds.

Based on this information and the assumption that

the ESCBAs air pressure gauges were accurate (both

gauges indicated that the air tanks were full), the

10–min. HH, CF, ESCBAs would have lasted

approximately six minutes and the 5 min., FF, PD,

ESCBA would have lasted approximately three

minutes (assuming same air consumption rate).

Inspection of the respiratory protection program

revealed strengths and weaknesses. Strengths of the

program included initial worker/visitor orientation

(video tapes and written materials) and training of

respiratory protection equipment (donning

procedures and respirator use) and refresher training

(weekly simulated drills). Another important

strength of the respirator program was the inspection

and maintenance of all respirator equipment and

cascade air systems were conducted by a contractor

that specialized in respiratory protection devices.

Weaknesses included the lack of a written program

and the absence of qualitative or quantitative

respirator fit testing other than a respirator fit check.

DISCUSSION/CONCLUSION

It is important to choose the proper respiratory

protection and instruct the worker in the correct

donning and maintenance procedures to prevent

health effects associated with exposure to the air

contaminate of concern. Because of the potential

adverse health effects of H2S exposures, only the

most protective respiratory protection should be

used. This includes any SCBA with a full facepiece

and operated in a PD mode or any supplied–air

respirator equipped with a full facepiece operated in

a PD mode in combination with an auxiliary SCBA

operated in a PD mode. Although MMS regulations

require offshore rigs to provide personnel with this

level of respiratory protection, MMS also allows

offshore facilities to use hooded, continuous flow

ESCBAs to increase the distribution of respirators on

the platforms.

Based on the information obtained during the

NIOSH site visit, it is recommended that the hooded,

continuous flow, ESCBAs should not be used

on offshore platforms. The ESCBA can be

over–breathed which can result in serious adverse
Page 8 Health Hazard Evaluation Report No. 96–0138

health effects. The wearer’s vision, which is slightly

distorted because of the polyurethane hood, can be

further distorted because of fogging of the hood

(moisture in exhaled breath) and the continuous

inflation/deflation of the hood (from

over–breathing). Lastly, NIOSH–approved hooded,

ESCBAs do not have airline capabilities. Therefore,

if a worker dons a 10–min. HH, CF, ESCBA during

an H2S release and cannot escape to a safe briefing

area for any reason (i.e., injury, blocked escape route,

etc.), then the worker will have to don another

respirator when the breathing air runs out. Also, if

the worker reaches the safe briefing area but does not

board the Whittaker, then the worker will have to

don another respirator when the breathing air runs

out. Changing respiratory protection for any reason

during an H2S release is not advised and should be

discouraged. In the event of an H2S release, platform

workers should don only one respirator which will

provide the highest level of protection and function

as a airline respirator. 

The only instance where hooded, continuous flow,

ESCBAs may be appropriate is when there are

visitors on the platform for less than 24 hours.

Visitor orientation and training of these respirators

require a minimal amount of time; and the simplicity

of donning these respirators can be advantageous in

an emergency situation because visitors likely do not

have advanced respirator training.

The air capsule respirators have several deficiencies

that were identified by MMS inspectors. Those

deficiencies include a limited air flow rate (breathing

air supplied to the hood) ranging from 17 to 25 Lpm,

air leaks in the air capsule coils, no airline hookup,

and a limited service life of 5–minutes or less (due to

leaks). Based on these deficiencies and the

deficiencies of other hooded ESCBAs identified by

NIOSH, the air capsule HH, CF, ESCBAs should not

be used on platform Irene (or any other platform) for

respiratory protection. 

Full facepiece, PD, SCBAs are designed so that as a

worker’s air consumption rate increases (platform

worker walking up steps to safe briefing area during

an H2S release), the air supply rate to the facepiece

also increases (maintaining positive pressure within

the facepiece). However, this could be viewed as a

disadvantage when using PD, SCBAs with a service

life of only five minutes. Since individual air

consumption rates are based on body dimensions,

age, sex, health, and fitness level and can differ from

person to person, respirator service life can differ

from person to person. The service time of an SCBA

is approved by NIOSH using a breathing machine

with 24 respirations per minute and a minute volume

of 40 liters.11 Therefore, if an individual’s air

consumption rate is greater than 40 Lpm, the service

life of the respirator will decrease. For example, the

estimated air consumption rate of an average

160 pound person walking up steps at a normal pace

(116 steps per minute) is approximately 60 Lpm.12, 13

A NIOSH–approved 5 min., FF, PD, SCBA contains

approximately 200 liters of breathing air

(40 Lpm X 5 min. = 200 Liters of air). Based on a

60 Lpm air consumption rate, the service life of the

5 min. ESCBA would be approximately three

minutes and twenty seconds, assuming a constant air

consumption rate (200 liters / 60 Lpm = 3.33 min.).

A 15 min. FF, PD, ESCBA contains approximately

600 liters of air. Based on a 60 Lpm air

consumption rate, the service life of the 15 min.

ESCBA would be approximately 10 minutes,

assuming a constant air consumption rate (600 liters

/ 60 Lpm = 10 min.). It should be noted that the

estimated air consumption rate described above is

only an approximation and is meant merely as a

general guide. A larger person moving at the same

rate will most likely have a greater air consumption

rate thus further decreasing the respirator service life

(assuming similar fitness levels, age, and sex).

Based on the above information and the fact that

individual air consumption rate vary from person to

person, the minimum service life of ESCBAs should

be 15 minutes. 

All respiratory protection used on offshore platforms

should be NIOSH–approved. Currently, NIOSH is

the only agency that approves/certifies the

performance of respiratory protection. MMS

regulation cites the ANSI standard Z 88.2 for

respiratory protection selection which requires that
Health Hazard Evaluation Report No. 96–0138 Page 9

all respiratory protection used should be

NIOSH–approved (or certified).

Although the airlines and detachable couplings were

compatible with SCBAs and ESCBAs that had

airline capabilities, they were not manufactured by

the same company as the respirators. When NIOSH

approves an SCBA (with airline capabilities), the

respirator is approved with the airline submitted by

the manufacturer. Therefore, the only airline used

for a specific SCBA should be from the same

manufacturer as the SCBA (i.e., MSA airline should

be used with MSA SCBA). If another airline or

couplings are used, then the NIOSH certification is

voided. 

During the survey, MMS inspectors expressed

concerns about the Whittaker and the ability of the

platform’s cascade system to maintain positive

pressure inside the escape pod when personnel

board. According to TOC, the current system

provides enough air so that the Whittaker is

maintained under positive pressure with the portal

both open and closed. Since this was not the focus of

the NIOSH site visit, investigators did not collect air

flow measurements or characterize air flow patterns

in the Whittaker. However, there may be a potential

for air (outside of Whittaker) to be entrained with

personnel into the Whittaker by various air currents

(eddy currents) created when entering the escape

pod. If air outside of the Whittaker is contaminated

with H2S, then it may be possible for H2S to migrate

inside the Whittaker. However, concentrations

would most likely be low because of the continuous

supply of air to the Whittaker. According to TOC,

H2S concentrations in the Whittaker are measured

with a portable monitor before personnel board. At

the current time, H2S has not been detected inside the

Whittaker during any H2S release. 

NIOSH investigators accompanied MMS inspectors

on a second platform that was owned and operated

by the Chevron Company to observe the Whittaker

breathing air systems and the respiratory protection

devices. The breathing air systems were similar with

the exception that the Whittaker cascade system on

the Chevron platform supplies breathing air to

personnel via airline, instead of into the general

environment of the Whittaker. This configuration

seems to be a safe and effective design that can be

used as a guide. Most respirator devices were PD,

FF, SCBAs and ESCBAs with service lives of

30 minutes and 5 minutes, respectively. A few HH,

CF, ESCBAs were utilized in remote locations on the

platform. 

In an attempt to gather more information on the use

of HH, CF, ESCBAs on offshore drilling rigs,

representatives from companies operating in the Gulf

of Mexico were contacted including Exxon and

Chevron. According to these companies, HH, CF,

ESCBAs are rarely used on offshore rig except in

remote locations were PD, FF, SCBAs are too large

to store and/or don.

RECOMMENDATIONS

The following recommendations are offered to

provide guidance in the development of a

comprehensive respiratory protection program and to

ensure that the highest level of respiratory protection

is provided to all personnel on platform Irene.

1. Only PD–type, FF, SCBAs with airline

capabilities and a service time of at least 15 minutes

should be used on platform Irene as well as other

platforms. Respirators should be distributed

throughout the platform in sufficient quantities to

ensure immediate access for all personnel.

2. Although a respiratory protection program was in

place on platform Irene, certain elements (e.g.,

writtern program and quantitative fit testing), were

deficient. A respiratory protection program should

include a written respiratory protection program,

regular worker training, airborne exposure

monitoring, routine procedures for maintenance,

proper storage of respirators, and quantitative fit

testing. It should also include a provision that

restricts workers from having any facial hair that

comes between the sealing surface of the facepiece

and the face. Furthermore, workers should not be

allowed to manipulate facial hair to create a good
Page 10 Health Hazard Evaluation Report No. 96–0138

1. NIOSH [1977]. Criteria for a Recommended

Standard. Occupational Exposure to Hydrogen

Sulfide. DHEW (NIOSH) Publication No.

77–158. Washington, DC: U.S. Government

Printing Office.

2. Beauchamp RO Jr. et al. [1984]. A critical

review of the literature on hydrogen sulfide

toxicity. CRC Crit Rev Toxicol 13:25–97.

3. Glass DC [1990]. A review of the health

effects of hydrogen sulfide exposure. Ann Occup

Hyg 34(3):323–327.

4. Schecter MT, Spitzer WO, Hutcheon ME

[1989]. Cancer downwind from sour gas

refineries: The perception and the reality of an

epidemic. Environ Health Perspect 79:283–290.

5. Bhamhani Y, Burnham R, Snydmiller G,

MacLean I, Martin T [1994]. Comparative

physiological responses of exercising men and

women to 5 ppm hydrogen sulfide exposure. Am

Ind Hyg Assoc J 55(11): 1030–1035.

6. NIOSH [1992]. Recommendations for

occupational safety and health: compendium of

policy documents and statements. Cincinnati,

OH: U.S. Department of Health and Human

Services, Public Health Service, Centers for

Disease Control and Prevention, National Institute

for Occupational Safety and Health, DHHS

(NIOSH) Publication No. 92–100.

7. Code of Federal Regulations [1993]. 29 CFR

1910.1000. Washington, DC: U.S . Government

Printing Office, Federal Register. 

8. ACGIH [1996]. 1996 threshold limit values

for chemical substances and physical agents and

biological exposure indices. Cincinnati, OH:

American Conference of Governmental Industrial

Hygienist.

9. Code of Federal Regulations [1997]. 30 CFR

Part 250: Hydrogen sulfide requirements for

operations in the outer continental shelf; final

rule. Washington, DC: U.S. Government Printing

Office, Federal Register.

10. American Petroleum Institute [1995]. API

Recommended Practices 55: Recommended

practices for oil and gas producing and gas

processing plant operations involving hydrogen

sulfide. 2nd ed. Washington, DC: American

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11. Code of Federal Regulation [1995]. 42 CFR

part 84. Respiratory protective devices.

Washington, DC: U.S. Government Printing

Office, Federal Register. 

12. Astrand P, Rodahl K. [1986]. Textbook of

work physiology. 3rd ed. New York, NY:

facepiece to face seal (i.e., folding a long mustache

while donning a respirator so a good seal can be

maintained). Publications developed by NIOSH and

OSHA can also be referenced when developing an

effective respirator program including the NIOSH

Respirator Decision Logic, the NIOSH Guide to

Industrial Respiratory Protection, and the OSHA

Respiratory Protection Standard (code of federal

regulation 1910.134).14, 15, 16

3. The number of breathing air manifolds (five

airlines per breathing air manifold) should be

increased at each safe briefing area. The quantity

should be determined by the number of non–essential

personnel who play an administrative role during

platform evacuation procedures. These roles may

include, and should not be limited to, director of

operations at safe briefing area, first aid setup,

communication and role call, H2S portable

monitoring equipment operator, and all Whittaker

operators. 

4. TOC should investigate the potential problem of

H2S being entrained with personnel into the

Whittaker when boarding the escape pod. If this is in

fact a problem, then an effective solution may be to

install airline hookups as was observed on the

Chevron platform. 

REFERENCES
Health Hazard Evaluation Report No. 96–0138 Page 11

McGraw–Hill Book Company, p. 491.

13. NIOSH [1984]. Personal protective

equipment for hazardous materials incidents: a

selection guide. Cincinnati, OH: U.S. Department

of Health and Human Services, Public Health

Service, Centers for Disease Control and

Prevention, National Institute for Occupational

Safety and Health, DHHS (NIOSH) Publication

No. 84–114.

14. NIOSH [1987]. NIOSH respirator decision

logic. Cincinnati, OH: U.S. Department of Health

and Human Services, Public Health Services,

Centers for Disease Control, National Institute for

Occupational Safety and Health, DHHS (NIOSH)

Publication No. 87–108.

15. NIOSH [1987]. NIOSH guide to industrial

respiratory protection. Cincinnati, OH: U.S.

Department of Health and Human Services, Public

Health Services, Centers for Disease Control,

National Institute for Occupational Safety and

Health, DHHS (NIOSH) Publication No. 87–116.

16. Code of Federal Regulations [1998]. 29 CFR

1910.134. Respiratory protection. Washington,

DC: U.S. Government Printing Office, Federal

Register.