DEPARTMENT OF HEALTH AND HUMAN SERVICES Public Health Service

National Institute for Occupational 

 Safety and Health 

Robert A. Taft Laboratories 

4676 Columbia Parkway 

Cincinnati OH 45226-1998 

11 August 2010

HETA 2010‐0115

Fred Tremmel

Deepwater Horizon ICP

1597 Highway 311

Houma, LA 70395

Dear Mr. Tremmel:

On May 28, 2010, the National Institute for Occupational Safety and Health (NIOSH) received a

request from BP for a health hazard evaluation (HHE). The request asked NIOSH to evaluate

potential exposures and health effects among workers involved in Deepwater Horizon

Response activities. NIOSH sent an initial team of HHE investigators on June 2, 2010, to begin

the assessment of off‐shore activities. To date, more than three dozen HHE investigators have

been on‐scene.  

This letter is the fourth in a series of interim reports. As this information is cleared for posting,

we will make it available on the NIOSH website (www.cdc.gov/niosh/hhe). When all field

activity and data analyses are complete we will compile the interim reports into a final report.  

This report (Interim Report #4) includes several discrete components of our investigation. For

each, we provide background, describe our methods, report the findings, and provide

conclusions and, where appropriate, interim recommendations. The components included in

this report are as follows:

• 4A – Evaluation of Vessels of Opportunity (VoOs) June 10–20, 2010  

• 4B –  Evaluation of Health Effects in Workers Performing Oil Skimming from Floating

City #1, June 19–23, 2010

• 4C – Evaluation of Source Control Vessels Development Driller II and Discoverer

Enterprise, June 21‐23, 2010
Thank you for your cooperation with this evaluation. If you have any questions, please do not

hesitate to contact me at 513.841.4382 or atepper@cdc.gov.

Sincerely yours,

Allison Tepper, PhD

Chief

Hazard Evaluations and Technical

   Assistance Branch

Division of Surveillance, Hazard

   Evaluations and Field Studies

3 Enclosures

cc:   

Mr. David Dutton, BP

Dr. Richard Heron, BP

Dr. Kevin O’Shea, BP

Mr. Joe Gallucci, BP  

Ms. Ursula Gouner, Transocean  

CDR Laura Weems, USCG

Mr. Clint Guidry, LA Shrimp Association

Ms. Cindy Coe, OSHA

Dr. Raoul Ratard, LA DHHS

Mr. Brock Lamont, CDC
4A‐1

Centers for Disease Control and Prevention 

National Institute for Occupational Safety and Health 

Health Hazard Evaluation of Deepwater Horizon Response Workers

HETA 2010­0115

Interim Report #4A

Evaluation of Vessels of Opportunity (VoOs) June 10–20, 2010  

Introduction

The Vessels of Opportunity (VoO) program was established by BP in response to the April 20, 2010,

Deepwater Horizon explosion and resultant oil spill in the Gulf of Mexico. As part of this program, local

vessel owners contracted their boats to conduct a variety of oil spill response activities including

booming and skimming operations, supporting on‐site burning of surface oil, tar ball recovery, and

providing transportation of supplies and personnel [BP 2010]. During June 10–20, 2010, NIOSH industrial

hygienists conducted industrial hygiene assessments on six fishing and shrimping trawlers in the VoO

program that were contracted by BP to remove surface oil by booming and skimming. These trawlers

typically ranged in size from 20 feet to more than 65 feet in length. On days when oil was not present on

the water surface in the areas to which these vessels were assigned, the vessel captains often directed

their vessels through patches of foam (described by the crew as “dispersant foam”) found on the sea

surface to break them up. The vessels were typically staffed by a captain and 1–2 deckhands who stayed

on the boat and 1–2 responders responsible for doing oil clean‐up work on the VoOs. These responders

were contract employees and were transported to the VoOs by crew boats on a daily basis.  

The VoOs evaluated were assigned under Group 1 Command which was divided into five task forces,

each of which was composed of five strike teams. Each strike team had five VoOs with a designated

strike team leader. The five task forces in Group 1 Command were located across a large geographic

area of the Gulf of Mexico, specifically from Breton Sound, Louisiana to the east of the southwest pass

of the Mississippi River. The VoOs were required to be out to sea from 6:00 a.m.to 6:00 p.m. scouting

for oil and conducting clean‐up work when oil was discovered. The vessels typically traveled at speeds of

less than 3.5 knots when scouting oil and traveled even slower (1–1.5 knots) when booms were used to

skim oil. Because of their size, most VoOs stayed within a three nautical mile zone from shore. VoOs

greater than 65 feet in length could travel beyond this three nautical mile zone. The VoOs docked

overnight in safe harbors near the shore.  

In addition to the VoOs, each task force had an Off Shore Vessel (OSV) that stayed anchored out at sea.

The OSVs are greater than 150 feet in length and have large open decks. The OSVs stored the clean‐up

supplies used by the VoOs including personal protective equipment (PPE), fuel, and water and were

responsible for distributing these items to the VoOs. They also stored on their decks the used absorbent

booms and other contaminated materials used by VoO workers during oil clean‐up work.   

Group 1 Command was based at Floating City #1 and was responsible for providing the VoOs with the

responders, food, and other supplies as needed. Floating City #1 was located at the north tip of Baptiste
4A‐2

Collette Bayou and had the capability of housing 225 personnel. On a typical morning, the responders

met at 5:30 a.m. to discuss safety issues of importance, followed by transport to their respective VoOs

by a number of crew boats. Upon completion of the work shift, the responders were brought back by

crew boats to the Floating City #1. The total time the responders spent traveling on the crew boats to

and from their assigned VoOs typically ranged from 4–6 hours per day.  

Responders and VoO personnel who conducted oil clean‐up work were provided and required to wear

yellow POSIWEAR®UBTM chemical protective suits, disposable nitrile gloves, 12” PIP ProCoat® PVC dipped

chemical resistant gloves, steel toe rubber boots, safety glasses, hard hats, and personal flotation

devices. In addition, nitrile gloves were required when cleaning the hard booms with diluted chemical

cleaners.

Six different VoOs were evaluated by NIOSH industrial hygienists from June 10–20, 2010. General area

(GA) and personal breathing zone (PBZ) air sampling was conducted on June 10, 2010 on board the Miss

Brandy; on June 15, 2010 on board the Talibah II and the Pelican; on June 16, 2010 on board the North

Star and the St. Martin; and on June 20, 2010 on board the Miss Carmen. Specifications for each VoO are

shown below in Table 1. The determinations on which strike teams and VoOs to which the NIOSH

industrial hygienists would be directed was made by Group 1 Command staff based on oil collection

reports from the previous few days.

Table 1. Specifications of VoOs on which air sampling was conducted from June 10–20, 2010

Sampling

Date VoO

Task

Force/

Strike

Team

Dimensions

(feet) Personnel Fuel

Smoking

Inside/Outside

Cabin

6/10/2010 Miss

Brandy TF‐5/ST‐5 72’ x 24’

Captain, 2

deckhands, 2

responders

Diesel Yes/Yes

6/15/2010 Talibah II TF‐5/ST‐1 38.5’ x 16’

Captain,

deckhand,

responder

Diesel No/No

6/15/2010 Pelican TF‐5/ST‐4 47’ x 18’

Captain, 2

deckhands,

responder

Diesel Yes/Yes

6/16/2010 North

Star TF‐5/ST‐3 62.7’ x 20’ Captain, 2deckhands Diesel No/No

6/16/2010 St. Martin TF‐5/ST‐5 60’ x 20’ Captain, 2

deckhands Diesel Yes/Yes

6/20/2010 Miss

Carmen TF‐4/ST‐2 46’ x 19’

Captain,

deckhand,

responder

Diesel No/Yes

While coordinating and preparing for the evaluations on board the VoOs, the NIOSH industrial hygienists

were informed that VoOs encountered oil patches around the Gulf of Mexico in a sporadic manner due

to the oil movement caused by Gulf currents. During the evaluation on June 10, 2010, the captain of the

Miss Brandy informed the NIOSH industrial hygienists that they had not encountered oil in over a week

and half. The vessel was tasked to scout for oil in a specific grid location on the east side of the
4A‐3

southwest pass of the Mississippi River. On the day of the NIOSH evaluation, Miss Brandy did not

encounter oil. However, the vessel did encounter what was described by the personnel as “residual

dispersant foam” present on the sea surface. The vessel spent time breaking up the long foam patches

by driving through them. Other VoOs in the nearby area were also performing the same operation. The

captain, deckhands, and responders spent most of their work shift inside the air conditioned cabin.  

NIOSH industrial hygienists were transported to different VoOs on June 15, 16, and 20, 2010, to conduct

evaluations during oil booming and clean‐up activities on these vessels. However, similar to the

evaluation on the Miss Brandy, no oil was encountered by these VoOs during the times when NIOSH

industrial hygienists were on board. The vessels did encounter similar foam patches which were broken

up by driving the boats through it. During these evaluations, VoO personnel and responders on the

vessels spent most of their time in the air conditioned cabins.   

Evaluation  

NIOSH investigators conducted longer‐term PBZ and GA air sampling on six different VoOs from June

10–20, 2010. The sampling period for longer‐term air samples on each vessel was 4–6 hours because

NIOSH industrial hygienists were directed to specific VoOs later in the morning of the day of the

evaluation once coordinates of the VoOs were determined by Group 1 Command staff. Additionally, the

responders were picked up approximately 2–3 hours before the end of the work day to allow for

adequate time to travel back to Floating City #1. Although sampling times were less than the actual

twelve hour shift times, the air sampling data represents worker exposures during the time when the

responders were present on the VoOs. Shorter‐term air samples evaluating specific tasks were not

collected due to the lack of oil clean‐up work activities on the days of the NIOSH evaluations.

To evaluate the presence of volatile organic compounds (VOCs), NIOSH investigators used integrated air

sampling with a variety of sampling media, including multi‐sorbent thermal desorption tubes followed

by thermal desorption/gas chromatography‐mass spectrometry (NIOSH Method 2549) and activated

charcoal tubes [NIOSH 2010]. Results of the thermal desorption tube air samples were used to select

specific VOCs for quantitation on PBZ and GA air samples collected using charcoal tubes. Other

chemicals measured in PBZ or GA air samples using integrated air sampling techniques included

propylene glycol (a component of the dispersant), diesel exhaust, mercury (a possible component of

crude oil), and the benzene soluble fraction of total particulate samples. Direct reading measurements

were made for carbon monoxide (CO) and hydrogen sulfide (H2S). The sampling and analytical methods

used are provided in Table 2.  

Results

Table 3 contains a summary of the relevant occupational exposure limits (OELs) to which results were

compared. Table 4 presents temperature and relative humidity (RH) measurements collected during the

days when air sampling was conducted by the NIOSH industrial hygienists. The deck temperatures for

the six VoOs ranged from 67–106 ̊F and the RH ranged from 30%–87%. The temperature inside the

vessels’ cabins ranged from 66–89 ̊F and the RH ranged from 29%–72%.  

Volatile Organic Compounds

Seven thermal desorption tube area air samples were collected to screen for VOCs on five of the six

VoOs. The screening samples collected during these sampling visits contained a variety of substances.
4A‐4

The major compounds detected on all vessels were C9 to C15 aliphatic hydrocarbons (straight and

branched alkanes). Additional compounds detected included benzene, toluene, xylenes, napthalenes,

and other substances. Limonene was also found on screening samples collected on board the Pelican

and the North Star.

Based on the results of the thermal desorption tube screening samples, 19 PBZ and GA charcoal tube air

samples were quantitated for benzene, ethyl benzene, limonene, naphthalene, toluene, total

hydrocarbons (THC) (as hexane), and xylenes. Results are shown in Tables 5–10. Air concentrations of

chemicals for which the air samples were analyzed were all well below their applicable OELs. Of the six

PBZ samples (collected on a deckhand and a responder on the Pelican and on a deckhand on the St.

Martin), limonene, THC, toluene, xylenes, and ethyl benzene were present above the minimum

quantifiable concentrations (MQC) (see Tables 7 and 9). Personnel on both VoOs spent time inside the

cabin as well as outdoors but did not engage in oil clean‐up related tasks. The highest THC PBZ

concentration was 6.0 milligrams per cubic meter (mg/m3

) and was collected on a deckhand on board

the Pelican. The highest THC GA concentration on any of the six vessels was 6.5 mg/m3 and was

collected inside the cabin of the Pelican. The THC GA concentrations were greater inside the cabins of

North Star and St. Martin when compared to the outside concentrations. Although there is no OEL

specifically for THCs, OELs for petroleum distillates and kerosene (two mixtures containing a similar

range of hydrocarbons as was found on the initial thermal tube air samples) are 350 mg/m3 as a work‐

shift time weighted average as shown in Table 2. Limonene is one of the ingredients in cleaning agents,

which might explain its presence in the air samples. Even on an additive basis, for any given exposure

period, the mixtures of chemicals measured in the air are a fraction (<10%) of the acceptable levels.

One GA air sample collected on Miss Carmen was quantitated for 2‐butoxyethanol, dipropylene glycol

butyl ether, and dipropylene glycol methyl ether (potential components in cleaners and oil dispersant).

None of the analytes were present in concentrations greater than their respective minimum detectable

concentrations (MDC) (Table 10).  

Propylene Glycol

The NIOSH industrial hygienists collected seven GA air samples for propylene glycol, a component of

Corexit 9500A (Nalco Company, Sugar Land, Texas), the dispersant in use at the time of the NIOSH

evaluation. One GA air sample was collected on the deck of each VoO. In addition, a NIOSH industrial

hygienist collected one GA air sample inside the cabin of the North Star. Propylene glycol was not

detected in six of the air samples and was present below the MQC in one air sample (Tables 5–10).

Diesel Exhaust

Emissions from diesel engines used to power the vessels are complex mixtures of gases and particulates.

NIOSH uses elemental carbon (EC) as a surrogate index of exposure because the sampling and analytical

method for EC is very sensitive, and a high percentage of diesel particulate (80‐90%) is EC. In

comparison, tobacco smoke particulate (a potential interference when measuring diesel exhaust) is

composed primarily of organic carbon (OC). Although OSHA and NIOSH have established OELs for some

of the individual components of diesel exhaust (i.e., nitrogen dioxide, CO), neither agency has

established an OEL for EC. However, the California Department of Health Services’ Hazard Evaluation

System & Information Service (HESIS) guideline for diesel exhaust particles (measured as EC) is

20 micrograms per cubic meter (μg/m3

) for an 8‐hour TWA. One air sample for diesel exhaust was

collected on the deck of each of the VoOs. As shown in Tables 5–10, EC concentrations ranged from 1.4–

9.1 μg/m3

, below the HESIS guideline. The OC concentrations ranged from less than 10–31 μg/m3.
4A‐5

Furthermore, diesel exhaust was not a substantial part of these sample results because the ratio of EC to

total carbon (the sum of EC + OC) ranged from 4.3%–48%, which is below the expected 60%–80% of EC

to total carbon typically reported in diesel exhaust.  

Mercury

The NIOSH industrial hygienists collected five GA air samples for mercury of which four were collected

on the decks of different VoOs and one was collected inside the cabin of North Star. Mercury air samples

were not collected on the Miss Carmen. No mercury was detected in the five area air samples. The

MDCs ranged up to 0.00005 mg/m3

, well below the most protective OEL of 0.025 mg/m3.

Benzene Soluble Total Particulate Fraction

Two PBZ air samples (collected on deckhands on the Pelican and the St. Martin) and eight GA air

samples (collected on all six VoOs) were collected for total particulates with the particulate fraction

analyzed for benzene soluble components (to separate out contributions from substances like salts from

the sea water) as an indicator of oil mist exposures (see Tables 5–10). Three of these eight GA air

samples were collected inside the cabins of the Pelican, the North Star, and the St. Martin. None of the

air samples contained detectable concentrations of benzene soluble particulates and none of the air

samples returned results above the MQC for total particulates.

Carbon Monoxide and Hydrogen Sulfide

Tables 5–10 include a summary of the direct reading measurements for CO and H2S. Carbon monoxide, a

component of incomplete combustion, possibly from the diesel engines, was monitored on the deck and

inside the cabins of various VoOs. Peak concentrations of CO ranged up to 15 parts per million (ppm),

with the highest TWA of 6 ppm, well below OELs. Hydrogen sulfide was not detected on six area samples

collected on the VoOs.  

Summary

During this evaluation, the VoOs on which the NIOSH industrial hygienists were present spent most of

their time scouting for oil and breaking up foam patches. Since no oil was encountered by these VoOs on

these days, NIOSH investigators did not observe any oil clean‐up work. The PBZ and area air

concentrations of the measured compounds were all well below OELs.  

Recommendations

The NIOSH industrial hygienists noted that employees were provided adequate PPE necessary to

conduct their jobs. However, the potential for dermal contact with the weathered oil and cleaning

agents exists when performing booming and skimming tasks. Due to this potential, it is recommended

that all personnel conducting oil clean‐up work on the VoOs ensure that the provided PPE is correctly

worn during such work to prevent possible dermal exposures.

While respiratory protection was not a required component of PPE for the deckhands or responders

conducting this oil clean‐up work, a NIOSH industrial hygienist on one of the VoOs was shown a 3MTM

half‐mask respirator with organic vapor/acid gas P100 cartridges by one of the deckhands. The

deckhand described the respirator as a part of the supplies provided to the boat. However, it was the

only respirator provided to the vessel which had three permanent workers stationed on it. The

deckhand noted that they were told that more respirators would be provided but were not delivered. It
4A‐6

is recommended that any PPE determined to be needed by the oil spill command staff be provided in

sufficient quantities for all workers present on the vessels. If respiratory protection is ever determined

to be required as part of the PPE ensemble, all the elements of the OSHA Respiratory Protection

Standard (29 CFR 1910.134), including fit testing, medical clearance, and proper training in the use of

the respirators should be followed.

While on one of the VoOs, a NIOSH industrial hygienist inquired about the use of cleaners provided to

the VoOs to clean their boats and booms. The deckhand responded that instructions had been provided

to him for the proper dilution and application of the cleaner. NIOSH industrial hygienists recommend

that proper training and instructions in the use of chemical cleaners be continued and that all VoO

personnel working with such chemicals follow these instructions throughout the course of their work.

The NIOSH industrial hygienists observed widespread use of tobacco products, particularly cigarettes

among the worker populations on most of the VoOs evaluated. Cigarette use by workers outside on the

decks of vessels as well as inside cabins was observed. Smoking is the single most preventable cause of

disease, disability, and death in the United States; an estimated 443,000 people die prematurely from

smoking or exposure to secondhand smoke, and another 8.6 million have a serious illness caused by

smoking [CDC 2010]. Eliminating cigarette smoking among Deepwater Horizon response workers on the

VoOs would be the most desirable recommendation. From all the research on cigarette smoking, we

know that quitting smoking has immediate as well as long‐term benefits for smokers and those around

them.   

References

ACGIH [2010]. 2010 TLVs® and BEIs®: threshold limit values for chemical substances and physical agents

and biological exposure indices. Cincinnati, OH: American Conference of Governmental Industrial

Hygienists.

AIHA [2009]. AIHA 2009 Emergency response planning guidelines (ERPG) & workplace environmental

exposure levels (WEEL) handbook. Fairfax, VA: American Industrial Hygiene Association.

BP [2010]. BP Gulf of Mexico response: vessels of opportunity. [http://www.bp.com/genericarticle

.do?categoryId=9034429&contentId=7062004]. Date accessed: July 2010.

CDC [2010]. Tobacco use, targeting the nation’s leading killer: at a glance 2010.

[http://www.cdc.gov/chronicdisease/resources/publications/AAG/osh.htm]. Date accessed: July 2010.

CDHS [2002]. Health hazard advisory: diesel engine exhaust. Oakland, CA:

California Department of Health Services, Hazard Evaluation System & Information Service.

[http://www.cdph.ca.gov/programs/hesis/Documents/diesel.pdf] Date accessed: July 2010.

CFR. Code of Federal Regulations. Washington, DC: U.S. Government Printing Office, Office of the

Federal Register.  

EPA [1999]. Compendium method TO‐15: determination of volatile organic compounds (VOCs) in air

collected in specially‐prepared canisters and analyzed by gas chromatography/mass spectrometry

(GC/MS), Second Edition. Center for Environmental Research Information, Office of Research and
4A‐7

Development, U.S. Environmental Protection Agency Cincinnati, OH.

[http://www.epa.gov/ttnamti1/files/ambient/airtox/to‐15r.pdf]. Date accessed: July 2010.

NIOSH [2005]. NIOSH pocket guide to chemical hazards. Cincinnati, OH: U.S. Department of Health and

Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety

and Health, DHHS (NIOSH) Publication No. 2005‐149. [www.cdc.gov/niosh/npg/]. Date accessed: July

2010.

NIOSH [2010]. NIOSH manual of analytical methods. 4th ed. Schlecht PC, O’Connor PF, eds. Cincinnati,

OH: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention,

National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 94‐113 (August

1994); 1st Supplement Publication 96‐135, 2nd Supplement Publication 98‐119, 3rd Supplement

Publication 2003‐154. [http://www.cdc.gov/niosh/nmam].
Table 2. Analytical methods used for substances evaluated during the June 10–20, 2010 VoOs

evaluation

Analyte Method

Benzene NMAM 1501*†

Benzene‐soluble fraction of total

particulates NMAM 5042

2‐Butoxyethanol NMAM1403‡

Carbon monoxide

Direct reading—GasAlert CO Extreme, BW Technologies Ltd.,

Calgary, Canada

Diesel exhaust (elemental carbon,

organic carbon, total carbon) NMAM 5040

Dipropylene glycol butyl ether NMAM1403‡

Dipropylene glycol methyl ether NMAM1403‡

Ethyl benzene NMAM 1501†

Hydrogen sulfide

Direct reading—GasAlert H2S Extreme, BW Technologies Ltd.,

Calgary, Canada

Limonene NMAM 1501†

Mercury NMAM 6009

Naphthalene NMAM 1501†

Propylene glycol NMAM 5523

Direct reading—HOBO® H8 ProSeries, Onset Computer Corporation,

Relative humidity Bourne, Massachusetts

Direct reading—HOBO® H8 ProSeries, Onset Computer Corporation,

Temperature Bourne, Massachusetts

Toluene NMAM 1501†

Total Hydrocarbons NMAM 1501†

Volatile organic compounds

(Screening) NMAM 2549 and EPA TO‐15§

Xylenes (Total) NMAM 1501†

*National Institute for Occupational Safety and Health (NIOSH) Manual of Analytical Methods [NIOSH 2010]

†Analysis for selected volatile organic compounds by an adaptation of the method

‡Analysis by an adaptation of the method

§Environmental Protection Agency [EPA 1999]

   

4B‐8  
Table 3. Occupational exposure limits for substances evaluated during the June 10–20, 2010 VoOs

evaluation

Chemical NIOSH RELa OSHA PELb ACGIH TLVc AIHA WEELd

Benzene 0.1 ppm TWAe

1 ppm STELg

1 ppm TWA

5 ppm STEL

0.5 ppm Action

Level

0.5 ppm TWA

2.5 ppm STEL

N/Af

Benzene‐soluble fraction of total

particulate

N/A N/A 0.5 mg/m3

TWAh

N/A

2‐Butoxyethanol 5 ppm TWA 50 ppm TWA 20 ppm TWA N/A

Carbon monoxide 35 ppm TWA

200 ppm

Ceiling

50 ppm TWA 25 ppm TWA N/A

Diesel exhaust (as elemental

carbon)i

N/A N/A N/A N/A

Dipropylene glycol butyl ether N/A N/A N/A N/A

Dipropylene glycol methyl ether 100 ppm TWA

150 ppm STEL

100 ppm TWA 100 ppm TWA

150 ppm STEL

N/A

Ethyl benzene 100 ppm TWA

125 ppm STEL

100 ppm TWA 100 ppm TWAj

125 ppm STEL

N/A

Hydrogen sulfide 10 ppm Ceiling

(10 min)

20 ppm

Ceilingk

1 ppm TWA

5 ppm STEL

N/A

Limonene N/A N/A N/A 30 ppm

Mercury 0.05 mg/m3

TWAl

0.1 mg/m3

TWAm

0.025 mg/m3

TWAm

N/A

Naphthalene 10 ppm TWA

15 ppm STEL

10 ppm TWA 10 ppm TWA

15 ppm STEL

N/A

10 mg/m3 Propylene glycol N/A N/A N/A

Toluene 100 ppm TWA

150 ppm STEL

200 ppm TWA

300 ppm

Ceiling

500 ppm Peak

(10 min max.)

20 ppm TWA N/A

Total hydrocarbons 350 mg/m3

TWA

1800 mg/m3

Ceiling  

(15 min)

(Petroleum

distillates)

2000 mg/m3

TWA

(Petroleum

distillates as

naphtha)

200 mg/m3

TWA

(Kerosene as

total

hydrocarbon

vapor)

N/A

   

4B‐9  
Table 3. Occupational exposure limits for substances evaluated during the June 10–20, 2010 VoOs

evaluation (continued)

Chemical NIOSH RELa OSHA PELb ACGIH TLVc AIHA WEELd

Xylenes 100 ppm TWA

150 ppm STEL

100 ppm TWA 100 ppm TWA

150 ppm STEL

N/A

a

National Institute for Occupational Safety and Health (NIOSH) recommended exposure limit (REL) [NIOSH 2005] b

Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) [29 CFR 1910] c

American Conference of Governmental Industrial Hygienists® (ACGIH) threshold limit value® (TLV) [ACGIH 2010] d

American Industrial Hygiene Association (AIHA) Workplace Environmental Exposure Level (WEEL) [AIHA 2009] e TWA = time weighted average f

N/A = not applicable g

STEL = short term exposure limit h

This OEL is for asphalt (bitumen) fume as benzene‐soluble aerosol but was considered appropriate because this

sampling was intended to differentiate between petroleum associated particulate and background particulate. i

California Department of Health Services’ Hazard Evaluation System & Information Service (HESIS) guideline for diesel

exhaust particles (measured as elemental carbon [EC]) is 20 μg/m3 for an 8‐hour TWA [CDHS 2002]

j

Proposed to be changed to 20 ppm TWA and STEL eliminated [ACGIH 2010] k

Exposures shall not exceed with the following exception: if no other measurable exposure occurs during the 8‐hour

work shift, exposures may exceed 20 ppm, but not more than 50 ppm (peak), for a single time period up to 10 minutes l

Elemental form  

mElemental and inorganic forms

   

4B‐10  
Table 4. Environmental conditions* during the June 10–20, 2010 VoOs evaluation

Vessel Temperature (°F)* Relative Humidity (%)*

June 10,2010 

Miss Brandy (Captain’s Cabin) 71 54–55;54

Miss Brandy (Dining Area) 71 55

Miss Brandy (M

pulley)

iddeck above 70 56–57;56

June 15, 2010 

Talibah II (Rear deck center) 87–91;89 55–71;64

Talibah II (Captain’s cabin) 87–89;88 62–66;63

Pelican (In Cabin) 83–89;85 29–61;39

Pelican (On deck) 89–95;93 48–65;55

June 16, 2010 

North Star (Inside cabin) 66–77;68 43–70;55

St. Martin (On deck)   80–106;94 30–72;52

St. Martin (In cabin) 77–81;81 37–72;45

June 20, 2010 

Miss Carmen (Rear deck center) 67–92;89 61–87;69

*Reported as range; average

Hours of monitoring: approximately 9:00 AM – 4:00 PM  

   

4B‐11  
Table 5. Area air concentrations for substances measured on June 10, 2010 on the Miss Brandy

Activity/Location Substance

Sampling

Information* Sample Concentration†‡ Time

(min)

Volume

(Liters)

Area Air Samples 

Starboard side deck Benzene 341 67.9 <0.001 ppm

Starboard side deck Benzene 340 68.7 <0.001 ppm

<0.04 mg/m3

Starboard side deck Benzene soluble

fraction

338 671

Captain’s Cabin Carbon Monoxide 406 N/A Range: 0–0 ppm; Avg: 0 ppm

Dining Area Carbon Monoxide 412 N/A Range: 0–0 ppm; Avg: 0 ppm

Middeck above pulley Carbon Monoxide 401 N/A Range: 0–0 ppm; Avg: 0 ppm

EC: (2.5 μg/m3); OC: (31 μg/m3 Portside of deck Diesel exhaust 338 670 )

Starboard side deck Ethyl benzene 341 67.9 <0.0007 ppm

Starboard side deck Ethyl benzene 340 68.7 <0.0007 ppm

Dining Area Hydrogen sulfide 412 N/A 0 ppm

Middeck above pulley Hydrogen sulfide 401 N/A 0 ppm

<0.00002 mg/m3 Portside of deck Mercury 529 105

Starboard side deck Naphthalene 341 67.9 (0.0034 ppm)

Starboard side deck Naphthalene 340 68.7 (0.0033 ppm)

<0.001 mg/m3 Portside of deck Propylene glycol 338 670

Starboard side deck Toluene 341 67.9 <0.0008 ppm

Starboard side deck Toluene 340 68.7 <0.0008 ppm

0.37 mg/m3 Starboard side deck Total hydrocarbons 341 67.9

0.37 mg/m3 Starboard side deck Total hydrocarbons 340 68.7

<0.06 mg/m3 Starboard side deck Total particulates 338 671

Starboard side deck Xylenes 341 67.9 (0.0014 ppm)

Starboard side deck Xylenes 340 68.7 (0.0014 ppm)

*N/A = not applicable

†Concentrations reported as “<” were not detected; the given value is the minimum detectable concentration

‡Concentrations in parentheses were between the minimum detectable concentration and the minimum quantifiable

concentration (parentheses are used to point out there is more uncertainty associated with these values than values above the

minimum quantifiable concentration)

   

4B‐12  
Table 6. Area air concentrations for substances measured on June 15, 2010 on the Talibah II

Activity/Location Substance

Sampling

Information* Sample Concentration†‡ Time

(min)

Volume

(Liters)

Area Air Samples 

Rear deck center Benzene 221 44.6 <0.002 ppm

Rear deck center Benzene 219 43.3 <0.002 ppm

<0.2 mg/m3

Rear deck center

Benzene soluble

fraction

219 435

Captain’s cabin Carbon Monoxide 234 N/A Range: 0‐6 ppm; Avg: 1 ppm

Rear deck end Carbon Monoxide 228 N/A Range: 0‐15 ppm; Avg: 2 ppm

EC: (1.6 μg/m3); OC: <20μg/m3 Rear deck center Diesel exhaust 224 446

Rear deck center Ethyl benzene 221 44.6 <0.001 ppm

Rear deck center Ethyl benzene 219 43.3 <0.001 ppm

Rear deck end Hydrogen sulfide 228 N/A 0 ppm

Rear deck center Limonene 221 44.6 <0.0008 ppm

Rear deck center Limonene 219 43.3 <0.0008 ppm

<0.00005 mg/m3 Rear deck center Mercury 220 43.2

Rear deck center Naphthalene 221 44.6 <0.0009 ppm

Rear deck center Naphthalene 219 43.3 <0.0009 ppm

<0.004 mg/m3 Rear deck center Propylene glycol 114 224

Rear deck center Toluene 221 44.6 <0.001 ppm

Rear deck center Toluene 219 43.3 <0.001 ppm

(0.0099 mg/m3 Rear deck center Total hydrocarbons 221 44.6 )

(0.014 mg/m3 Rear deck center Total hydrocarbons 219 43.3 )

<0.09 mg/m3 Rear deck center Total particulates 219 435

Rear deck center Xylenes 221 44.6 <0.002 ppm

Rear deck center Xylenes 219 43.3 <0.002 ppm

*N/A = not applicable

†Concentrations reported as “<” were not detected; the given value is the minimum detectable concentration

‡Concentrations in parentheses were between the minimum detectable concentration and the minimum quantifiable

concentration (parentheses are used to point out there is more uncertainty associated with these values than values above the

minimum quantifiable concentration)

   

4B‐13  
Table 7. Personal breathing zone and area air concentrations for substances measured on June 15,

2010 on the Pelican

Activity/Location Substance

Sampling

Information* Sample Concentration†‡ Time

(min)

Volume

(Liters)

Personal Breathing Zone Air Samples—Worker A§

<0.2 mg/m3

Deckhand   Benzene soluble 247 480

fraction

Deckhand Total particulates 247 480 (0.18 mg/m3

)

Personal Breathing Zone Air Samples—Worker B§

Responder Benzene 215 42.5 <0.002 ppm

Responder Benzene 214 42.1 <0.002 ppm

Responder Ethyl benzene 215 42.5 <0.001 ppm

Responder Ethyl benzene 214 42.1 <0.001 ppm

Responder Limonene 215 42.5 0.013 ppm

Responder Limonene 214 42.1 0.0077 ppm

Responder Naphthalene 215 42.5 <0.0009 ppm

Responder Naphthalene 214 42.1 <0.0009 ppm

Responder Toluene 215 42.5 <0.001 ppm

Responder Toluene 214 42.1 <0.001 ppm

0.092 mg/m3 Responder Total hydrocarbons 215 42.5

0.059 mg/m3 Responder Total hydrocarbons 214 42.1

Responder Xylenes 215 42.5 <0.002 ppm

Responder Xylenes 214 42.1 <0.002 ppm

Personal Breathing Zone Air Samples—Worker C§

Deckhand Benzene 234 46.7 (0.0027 ppm)

Deckhand Benzene 232 46.0 (0.0025 ppm)

Deckhand Ethyl benzene 234 46.7 0.0084 ppm

Deckhand Ethyl benzene 232 46.0 0.0085 ppm

Deckhand Limonene 234 46.7 0.085 ppm

Deckhand Limonene 232 46.0 0.085 ppm

Deckhand Naphthalene 234 46.7 (0.013 ppm)

Deckhand Naphthalene 232 46.0 (0.012 ppm)

Deckhand Toluene 234 46.7 0.015 ppm

Deckhand Toluene 232 46.0 0.016 ppm

5.8 mg/m3 Deckhand Total hydrocarbons 234 46.7

6.0 mg/m3 Deckhand Total hydrocarbons 232 46.0

Deckhand Xylenes 234 46.7 0.035 ppm

Deckhand Xylenes 232 46.0 0.035 ppm

   

4B‐14  
Table 7. Personal breathing zone and area air concentrations for substances measured on June 15,

2010 on the Pelican (continued)

Activity/Location Substance

Sampling

Information* Sample Concentration†‡ Time

(min)

Volume

(Liters)

Area Air Samples 

In Cabin Benzene 236 46.0 (0.0031 ppm)

<0.2 mg/m3 On deck Benzene soluble

fraction

249 497

<0.2 mg/m3 In Cabin Benzene soluble

fraction

249 490

On deck Carbon Monoxide 255 N/A Range: 0–13 ppm; Avg: 3 ppm

EC: (2.8 μg/m3); OC: <20 μg/m3 On deck Diesel exhaust 255 502

In Cabin Ethyl benzene 236 46.0 0.0095 ppm

On deck Hydrogen sulfide 256 N/A 0 ppm

In Cabin Limonene 236 46.0 0.082 ppm

On deck Mercury 236 46.2 <0.00004 ppm

In Cabin Naphthalene 236 46.0 (0.012 ppm)

<0.002 mg/m3 On deck Propylene glycol 251 490

In Cabin Toluene 236 46.0 0.017 ppm

6.5 mg/m3 In Cabin Total hydrocarbons 236 46.0

<0.08 mg/m3 On deck Total particulates 249 497

<0.08 mg/m3 In Cabin Total particulates 249 490

In Cabin Xylenes 236 46.0 0.039 ppm

*N/A = not applicable

†Concentrations reported as “<” were not detected; the given value is the minimum detectable concentration

‡Concentrations in parentheses were between the minimum detectable concentration and the minimum quantifiable

concentration (parentheses are used to point out there is more uncertainty associated with these values than values above the

minimum quantifiable concentration)

§Worker smoked

   

4B‐15  
Table 8. Area air concentrations for substances measured on June 16, 2010 on the North Star

Activity/Location Substance

Sampling

Information* Sample Concentration†‡ Time

(min)

Volume

(Liters)

Area Air Samples 

Inside Cabin Benzene 218 43.3 <0.002 ppm

Inside Cabin Benzene 217 44.1 <0.002 ppm

Outside rear center Benzene 207 41.5 <0.002 ppm

Outside rear center Benzene 208 40.6 <0.002 ppm

<0.2 mg/m3 Inside Cabin Benzene soluble

fraction

223 442

Outside rear center Carbon Monoxide 209 N/A Range: 0‐9 ppm; Avg: 6 ppm

Inside Cabin Carbon Monoxide 214 N/A Range: 0‐0 ppm; Avg: 0 ppm

EC: (1.5 μg/m3); OC: <20μg/m3 Outside rear center Diesel exhaust 207 416

Inside Cabin Ethyl benzene 218 43.3 <0.001 ppm

Inside Cabin Ethyl benzene 217 44.1 <0.001 ppm

Outside rear center Ethyl benzene 207 41.5 <0.001 ppm

Outside rear center Ethyl benzene 208 40.6 <0.001 ppm

Outside rear center Hydrogen sulfide 209 N/A 0 ppm

Inside Cabin Limonene 218 43.3 0.011 ppm

Inside Cabin Limonene 217 44.1 0.011 ppm

Outside rear center Limonene 207 41.5 (0.0010 ppm)

Outside rear center Limonene 208 40.6 (0.0019 ppm)

0.00005 mg/m3 Inside Cabin Mercury 219 44.2

Inside Cabin Naphthalene 218 43.3 <0.0009 ppm

Inside Cabin Naphthalene 217 44.1 <0.0009 ppm

Outside rear center Naphthalene 207 41.5 <0.0009 ppm

Outside rear center Naphthalene 208 40.6 <0.0009 ppm

<0.002 mg/m3 Inside Cabin Propylene glycol 222 440

(0.012 mg/m3 Outside rear center Propylene glycol 206 401 )

Inside Cabin Toluene 218 43.3 (0.0028 ppm)

Inside Cabin Toluene 217 44.1 (0.0029 ppm)

Outside rear center Toluene 207 41.5 <0.001 ppm

Outside rear center Toluene 208 40.6 <0.001 ppm

0.62 mg/m3 Inside Cabin Total hydrocarbons 218 43.3

0.63 mg/m3 Inside Cabin Total hydrocarbons 217 44.1

0.059 mg/m3 Outside rear center Total hydrocarbons 207 41.5

0.12 mg/m3 Outside rear center Total hydrocarbons 208 40.6

<0.09 mg/m3 Inside Cabin Total particulates 223 442

Inside Cabin Xylenes 218 43.3 (0.0027 ppm)

Inside Cabin Xylenes 217 44.1 (0.0028 ppm)

Outside rear center Xylenes 207 41.5 <0.002 ppm

Outside rear center Xylenes 208 40.6 <0.002 ppm

*N/A = not applicable

†Concentrations reported as “<” were not detected; the given value is the minimum detectable concentration

‡Concentrations in parentheses were between the minimum detectable concentration and the minimum quantifiable

concentration (parentheses are used to point out there is more uncertainty associated with these values than values above the

minimum quantifiable concentration)

   

4B‐16  
Table 9. Personal breathing zone and area air concentrations for substances measured on June 16,

2010 on the St. Martin

Activity/Location Substance

Sampling

Information* Sample Concentration†‡ Time

(min)

Volume

(Liters)

Personal Breathing Zone Air Samples—Worker A§

<0.2 mg/m3

Deckhand   Benzene soluble 224 434

fraction

Deckhand Total particulates 224 434 <0.09 mg/m3

Personal Breathing Zone Air Samples—Worker B§

Deckhand Benzene 221 44.3 <0.002 ppm

Deckhand Benzene 220 43.0 <0.002 ppm

Deckhand Ethyl benzene 221 44.3 <0.001 ppm

Deckhand Ethyl benzene 220 43.0 <0.001 ppm

Deckhand Limonene 221 44.3 0.011 ppm

Deckhand Limonene 220 43.0 0.011 ppm

Deckhand Naphthalene 221 44.3 <0.0009 ppm

Deckhand Naphthalene 220 43.0 <0.0009 ppm

Deckhand Toluene 221 44.3 (0.0041 ppm)

Deckhand Toluene 220 43.0 (0.0044 ppm)

0.59 mg/m3 Deckhand Total hydrocarbons 221 44.3

0.58 mg/m3 Deckhand Total hydrocarbons 220 43.0

Deckhand Xylenes 221 44.3 (0.0035 ppm)

Deckhand Xylenes 220 43.0 (0.0034 ppm)

Area Air Samples 

On deck Benzene 225 44.3 <0.002 ppm

On deck Benzene 224 43.8 <0.002 ppm

In cabin Benzene 217 43.6 <0.002 ppm

<0.2 mg/m3 On deck Benzene soluble

fraction

229 449

<0.2 mg/m3 In cabin Benzene soluble

fraction

215 429

On deck Carbon Monoxide 235 N/A Range: 0–4 ppm; Avg: 3 ppm

EC: (1.4  μg/m3); OC: (31 μg/m3 On deck Diesel exhaust 230 450 )

On deck Ethyl benzene 225 44.3 <0.001 ppm

On deck Ethyl benzene 224 43.8 <0.001 ppm

In cabin Ethyl benzene 217 43.6 (0.0011 ppm)

On deck Hydrogen sulfide 235 N/A 0 ppm

On deck Limonene 225 44.3 (0.0011 ppm)

On deck Limonene 224 43.8 (0.0013 ppm)

In cabin Limonene 217 43.6 0.017 ppm

On deck Mercury 214 41.6 <0.00005 ppm

On deck Naphthalene 225 44.3 <0.0009 ppm

On deck Naphthalene 224 43.8 (0.0010 ppm)

In cabin Naphthalene 217 43.6 (0.0021 ppm)

<0.002 mg/m3 On deck Propylene  glycol 225 440

On deck Toluene 225 44.3 (0.0022 ppm)

On deck Toluene 224 43.8 (0.0016 ppm)

In cabin Toluene 217 43.6 0.0057 ppm

   

4B‐17  
Table 9. Personal breathing zone and area air concentrations for substances measured on June 16,

2010 on the St. Martin (continued)

Activity/Location Substance

Sampling

Information* Sample Concentration†‡ Time

(min)

Volume

(Liters)

Area Air Samples 

0.27 mg/m3 On deck Total hydrocarbons 225 44.3

0.30 mg/m3 On deck Total hydrocarbons 224 43.8

0.85 mg/m3 In cabin Total hydrocarbons 217 43.6

<0.09 mg/m3 On deck Total particulates 229 449

<0.09 mg/m3 In cabin Total particulates 215 429

On deck Xylenes 225 44.3 (0.0029 ppm)

On deck Xylenes 224 43.8 (0.0032 ppm)

In cabin Xylenes 217 43.6 (0.0042 ppm)

*N/A = not applicable

†Concentrations reported as “<” were not detected; the given value is the minimum detectable concentration

‡Concentrations in parentheses were between the minimum detectable concentration and the minimum quantifiable

concentration (parentheses are used to point out there is more uncertainty associated with these values than values above the

minimum quantifiable concentration)

   

4B‐18  
4B‐19  

Table 10. Area air concentrations for substances measured on June 20, 2010 on the Miss Carmen

Activity/Location Substance

Sampling

Information* Sample Concentration†‡ Time

(min)

Volume

(Liters)

Area Air Samples 

Rear deck center Benzene 345 69.0 <0.001 ppm

Rear deck center Benzene soluble

fraction

343 711 <0.07 mg/m3

Rear deck center 2‐Butoxyethanol 304 61.1 < 0.0007 ppm

Rear deck center Carbon Monoxide 343 N/A Range: 0–6 ppm; Avg: 4 ppm

Inside cabin Carbon Monoxide 357 N/A Range: 0–4 ppm; Avg: 2 ppm

Rear deck center Diesel exhaust 342 706 EC: 9.1.4 μg/m3; OC: <10 μg/m3

Rear deck center Dipropylene glycol

butyl ether 304 61.1 (0.0060 ppm)

Rear deck center Dipropylene glycol

methyl ether 304 61.1 <0.001 ppm

Rear deck center Ethanol 345 69.0 <0.003 ppm

Rear deck center Ethyl benzene 345 69.0 <0.0007 ppm

Rear deck center Limonene 345 69.0 <0.0005 ppm

Rear deck center Naphthalene 345 69.0 <0.0006 ppm

Rear deck center Propylene glycol 338 670 <0.001 mg/m3

Rear deck center Toluene 345 69.0 <0.0008 ppm

Rear deck center Total hydrocarbons 345 69.0 (0.0086 mg/m3)

Rear deck center Total particulates 343 711 <0.04 mg/m3

Rear deck center Xylenes 345 69.0 <0.001 ppm

*N/A = not applicable

†Concentrations reported as “<” were not detected; the given value is the minimum detectable concentration

‡Concentrations in parentheses were between the minimum detectable concentration and the minimum quantifiable

concentration (parentheses are used to point out there is more uncertainty associated with these values than values above the

minimum quantifiable concentration)
Centers for Disease Control and Prevention 

National Institute for Occupational Safety and Health 

Health Hazard Evaluation of Deepwater Horizon Response Workers

HETA 2010­0115

Interim Report # 4B

Evaluation of Health Effects in Workers Performing Oil Skimming from Floating

City #1, Louisiana, June 19–23, 2010

Introduction

To better assess health symptoms among off‐shore response workers, NIOSH investigators traveled to

Floating City #1 on June 19–23, 2010 to collect self‐administered health symptom surveys from two

types of workers involved in off‐shore oil skimming: 130 contracted laborers (“responders”) who were

responsible for oil clean‐up work, and more than 300 shrimp boat captains and deck hands, who

operated the approximately 125 boats taking part in the operations. Each boat had a captain, one or

two deck hands, and one or two responders. The responders were temporarily housed on Floating City

#1 located 10 miles northeast of Venice, Louisiana, at the mouth of the Baptiste Collette channel. Each

morning and evening, responders were transported to and from the shrimp boats deployed southwest

of Floating City #1 by crew boats. Their 12‐hour work shifts included travel time as well as time spent on

the shrimp boats. Shrimp boat captains and deck hands did not return to Floating City #1 but remained

on their boats overnight.

  

Methods

Surveys, available in English and Spanish, were collected from responders at the end of their workday as

they gathered for dinner on the floating city. The following morning, surveys and sealable envelopes

were given to the designated leads of responder teams to distribute to captains and deck hands, collect

before leaving the work area, and return to NIOSH investigators at the floating city at the end of the day.

Workers were asked to report symptoms they experienced while working during response activities.

Results

One hundred and twenty‐one (93%) of 130 responders and 68 (18%) of 370 eligible captains and deck

hands completed the health symptom survey. Demographically, the age and sex distributions of the two

groups were similar to each other and to a comparison group of participants (who had been recruited

from the Venice Field Operations Branch and the Venice Commanders’ Camp and reported that they

had not worked on boats and had no exposures to oil, dispersant, cleaner, or other chemicals)  (See

Table 1.).

Reported symptoms, grouped by type, are presented in Table 2, which includes symptoms for   

responders, captains, and deck hands, and the comparison group of workers. Overall, the most

frequently reported symptoms by all groups were upper respiratory irritation and headaches. Scrapes

and cuts were the most frequently reported injuries among responders. Although the survey did not

have a question about smoking status, NIOSH investigators noted that a large number of the response

4B‐1  
workers on the floating city were smoking and reported that some ex‐smokers said they started smoking

again after beginning response work.

Summary

The types of symptoms reported among responders, captains, and deckhands were similar to those

reported by response workers who reported no exposures to oil, dispersant, cleaner, or other chemicals.

Symptoms related to heat exposure and upper respiratory symptoms were the most frequently

reported in all groups.  These types of symptoms can be related to a combination of several factors,

including heat and humidity, sun exposure, psychosocial stress, and tobacco smoke.  We do not believe

that the symptoms reported are consistent with exposure to oil, oil constituents, or dispersants.

Although this report focuses on responders, captains, and deckhands involved in oil skimming, we would

be remiss not mentioning cigarette smoking.  Implementing a no‐smoking policy at this late date raises

ethical concerns and practical challenges; however, in the future it may be justified in light of the harms

resulting from exposure to tobacco smoke and the lack of other avenues of redress for nonsmoking

workers. The same legal, practical, and health issues that have driven successful efforts to make other

workplaces smoke‐free argue in favor of extending similar protection to emergency response workers.

4B‐2  
Table 1. Health symptom survey−demographics by group

BP Responders Captains and

Deck Hands

Unexposed*

Number of Participants 121 69 103

Age range 18‐63 18‐65 18‐70

Race

    White      

    Hispanic

    Asian

    Black

    Other

    Not specified

26%

28%

0  

37%

  5%

  3%

55%

  4%

26%

10%

  3%

  1%

40%

29%

  9%

19%

  3%

Male 98% 99% 96%

Days worked oil spill 1‐60 0‐60 0‐45

Days worked boat 0‐60 0‐56 0

*Participants were recruited from the Venice Field Operations Branch and the Venice Commanders’ Camp. Those who reported

that they had not worked on boats and had no exposures to oil, dispersant, cleaner, or other chemicals were included in this

group.

   

4B‐3  
4B‐4  

Table 2. Health symptom survey−reported injuries and symptoms  

BP

Responders

Captains

and

Deck Hands

Unexposed *

Number of participants 121 69 103

Injuries

Scrapes or cuts 12 (10%) 3 (4%) 11 (11%)

Burns by fire 0 0 1 (1%)

Chemical burns 0 0 0

Bad Sunburn 4 (3%) 1 (1%) 8 (8%)

Constitutional symptoms  

Headaches 13 (11%) 9 (13%) 5 (5%)

Feeling faint, dizziness, fatigue or exhaustion, or weakness 5 (4%) 5 (7%) 13 (13%)

Eye and upper respiratory symptoms

Itchy eyes 5 (4%) 0 5 (5%)

Nose irritation, sinus problems, or sore throat 11 (9%) 10 (14%) 16 (16%)

Metallic taste 0 1 (1%) 0

Lower respiratory symptoms

Coughing 8 (7%) 4 (6%) 8 (8%)

Trouble breathing, short of breath, chest tightness, wheezing 2 (2%) 2 (3%) 4 (4%)

Cardiovascular symptoms

Fast heart beat 0 0 1 (1%)

Chest pressure 0 1 (1%) 0

Gastrointestinal symptoms

Nausea or vomiting 3 (2%) 3 (4%) 3 (3%)

Stomach cramps or diarrhea 5 (4%) 2 (3%) 7 (7%)

Skin symptoms

Itchy skin, red skin, or rash 5 (4%) 0 8 (8%)

Musculoskeletal symptoms

Hand, shoulder, or back pain 3 (2%) 2 (3%) 6 (6%)

Psychosocial symptoms

Feeling worried or stressed 2 (2%) 4 (6%)        4 (4%)

Feeling pressured 1 (1%) 1 (1%)       2 (2%)

Feeling depressed or hopeless 1 (1%) 0       1 (1%)

Feeling short tempered 0 1 (1%)       4 (4%)

Frequent changes in mood 0 1 (1%)       3 (3%)

Heat stress symptoms†

Any 18 (15%) 12 (17%) 21 (20%)

4 or more symptoms 2 (2%) 1 (1%) 3 (3%)

* Participants were recruited from the Venice Field Operations Branch and the Venice Commanders’ Camp. Those who reported

that they had not worked on boats and had no exposures to oil, dispersant, cleaner, or other chemicals were included in this

group.  

† Headache, dizziness, feeling faint, fatigue or exhaustion, weakness, fast heart beat, nausea, red skin, or hot and dry skin.
Centers for Disease Control and Prevention 

National Institute for Occupational Safety and Health 

Health Hazard Evaluation of Deepwater Horizon Response Workers

HETA 2010­0115

Interim Report #4C

Evaluation of Source Control Vessels Development Driller II and Discoverer

Enterprise, June 21­23, 2010

Introduction

On June 21‐23, 2010, NIOSH investigators conducted industrial hygiene surveys and collected self‐

administered health symptom surveys aboard two vessels located at the site of the Deepwater Horizon

Mississippi Canyon (MC) 252 Well No. 1 oil release. This site visit was part of the NIOSH response to a

series of Health Hazard Evaluation (HHE) requests that were received from BP concerning workers

involved in the Deepwater Horizon response.  

Background

MC252 Well No. 1 is located approximately 50 miles southeast of Venice, Louisiana, at a depth of about

5,000 feet. On June 21‐23, 2010, the four primary vessels at the Deepwater Horizon MC252 location

were two semi‐submersible drilling rigs (Development Driller II (DD II) and Development Driller III (DD

III)), a drillship (Discoverer Enterprise), and a semi‐submersible multipurpose oil field construction and

intervention vessel (Q4000). The DD II, DD III, and Discoverer Enterprise are operated by Transocean;

the Q4000 is operated by Helix Energy Solutions Group. At the time of the NIOSH evaluation, DD II and

DD III were drilling relief wells for the purpose of pumping mud into the blown well to suppress the

release of crude oil, followed by concrete to seal the well [BP 2010a]. The Discoverer Enterprise, which

was located directly above the blown well, captured oil and gas from the damaged well through a lower

marine riser package cap [BP 2010b], which was placed on top of the failed Deepwater Horizon blowout

preventer (BOP). Captured oil and gas traveled through the riser insertion tube to the Discoverer

Enterprise where gas was separated from the oil, and was burned at the flare boom on the starboard

side of the vessel [Deepwater Horizon Unified Command 2010]. Captured oil was stored temporarily

aboard the Discoverer Enterprise until it was pumped into an oil tanker. The oil storage capacity of the

Discoverer Enterprise is 100,000 barrels [Net Resources International 2010]. The Q4000 draws oil and

gas from the choke and kill lines on the BOP. Approximately 9,000 barrels of oil were flared each day by

the Q4000. A visible plume of combustion products was generated by the Q4000 flare. The Discoverer

Enterprise and Q4000 were generally positioned so that the flare booms were perpendicular to wind

direction to carry combustion products away from the vessels.

  

Development Driller II  

The DD II is a semisubmersible drilling unit with an operating water depth of 7,500 feet (ft) and a drilling

depth of 37,500 ft (See Figure 1). The main deck width and length are both about 244 ft [Transocean

2010a]. The DD II went into service in 2004 [Transocean 2010b]. The rig contains all equipment and

4C‐1  
materials for drilling operations including cranes, drilling equipment, hoisting equipment, storage, drill

mud conditioning (mixing, cleaning, recirculating) and well‐control equipment. The DD II was not

involved with oil collection from the damaged BOP and at the time of the NIOSH evaluation was

operating in drilling mode, along with DD III. The water surface distance between the DD II and the

Discoverer Enterprise was about 2400 ft; the distance to the DD III was about 2500 ft. One hundred

sixty‐seven people were on board the DD II during the NIOSH evaluation. This included 95 Transocean

workers, 21 Transocean third party workers, and other personnel with the client (BP) or client third

party employers.  

Figure 1. GSF Development Driller II. Photo courtesy Transocean Ltd.

Personnel outside of living quarters, offices, and non‐hazardous interior work areas were required to

wear hard hats, coveralls, gloves, hearing protection, and safety glasses. Personal flotation devices were

required during activities presenting a potential for entry into the water. All personnel were required to

be fit tested and were equipped with 3M 6000 series half‐mask and full‐facepiece air purifying

respirators equipped with organic vapor/acid gas/P100 cartridges. No oil dispersion agent was used by

or stored aboard the DD II. Potential for exposure to crude oil from the MC252 Well No. 1 and dispersion

agent was limited to that on the water surrounding the DD II. No activities requiring contact by workers

aboard the DD II with crude oil or dispersion agent containing seawater were identified by NIOSH

investigators.

Discoverer Enterprise

The Discoverer Enterprise is a deepwater double‐hulled dynamically positioned drillship (see Figure 2).

The Discoverer Enterprise can perform a range of subsea operations including laying ultra deepwater

pipelines and providing extended well testing and storage capabilities. It has an operating water depth

of 10,000 ft. and a drilling depth of 35,000 ft. The vessel is 835 ft. long and 125 ft. wide with a height of

418 ft [Transocean 2010c]. The Discoverer Enterprise went into service in 1999 [Transocean 2010b]. The

vessel contains dual rotary tables operating under one massive derrick. In addition to containing all the

equipment and materials found on drilling rigs, the Discoverer Enterprise can collect and hold about

100,000 barrels of crude oil. At the time of the HHE, the Discoverer Enterprise was located over the

damaged MC252 Well BOP and was operating in a recovery and production mode, collecting about

25,000 barrels of oil per day. The vessel had a flare boom located on the starboard side which

continuously burned gases coming up with the oil captured from the lower marine riser package cap.

One hundred eighty‐six people were on board during the NIOSH evaluation. The largest numbers of

4C‐2  
workers were with Transocean (93 workers), Schlumberger (22), ART Catering – [quarters operation]

(19), Oceaneering – [Remotely Operated Vehicles on the ocean floor] (13), and BP (8).

Figure 2. Discoverer Enterprise. Photo courtesy of Transocean Ltd.

Personnel outside of quarters or non‐hazardous work spaces were required to wear hard hats, flame

retardant coveralls, gloves, hearing protection, and safety glasses. Because of the high noise level

generated by the Discoverer Enterprise flare, double hearing protection (earplugs and ear muffs) was

required in designated areas. Personal flotation devices were required during activities presenting a

potential for entry into the water. All personnel were required to be fit tested and have in their

possession 3M 6000 series half‐mask and full‐facepiece air purifying respirators equipped with organic

vapor/acid gas/P100 cartridges. Workers on deck and in hazardous work spaces on the Discoverer

Enterprise were required to carry their respirators and double hearing protection with them. The

cartridges used for the air purifying respirators had been changed from organic vapor/P100 to cartridges

including acid gas. This modification was implemented after the Q4000 began flaring oil and gas on June

16 [BP 2010c].  

Operations aboard the Discoverer Enterprise included transfer of crude oil to oil tankers; operation of

remotely operated vehicles (ROVs) near the ocean floor; collection and storage of crude oil; separation

of gas from the oil; burning gas at the flare boom; and use of methanol as an anti‐freezing agent at

depth to reduce icing due to gas hydrate formation. NIOSH investigators were told that no dispersants

had been used or stored on the Discoverer Enterprise. Application of dispersion agent was performed on

an as‐needed basis by other vessels in the area. The dispersion agent had been applied either at the

surface or injected at depth. During the NIOSH evaluation on June 23, 2010, the Discoverer Enterprise

was transferring about 80,000 barrels of crude oil to the oil tanker Overseas Cascade.

Recovery and production operations aboard the Discoverer Enterprise deviated from routine activities

during the NIOSH evaluation on June 23, 2010. At approximately 8 a.m., an alarm was sounded

throughout the vessel implementing a muster. All nonessential personnel reported to the galley to be

accounted for and to gather in groups by lifeboat assignment. Rising seawater in the riser connecting

the Discoverer Enterprise to the damaged well, and through which oil was transported up to the vessel,

was occurring. This triggered concern because a decrease in the outflow of seawater from the annulus

of the riser at the sea floor may indicate the presence of gas accumulation in the riser and a potential

loss of control over the well. Personnel were required to remain at the vessel’s muster location until

4C‐3  
corrective actions were taken to address the immediate concern. Difficulty discerning the cause of rising

seawater in the riser prompted implementation of protective measures and an emergency disconnect of

the riser from the well. Further investigation disclosed that there was no gas in the riser. A discharge

valve on the riser near the collection point at the well had inadvertently been closed resulting in a

malfunction. Following the identification and correction of the malfunction, the Discoverer Enterprise

riser was reconnected to the well, and resumption of operations and oil collection occurred at

approximately 7:50 p.m.

BP Offshore Air Monitoring Activities for Source Control

Monitoring for personal and area airborne concentrations of various contaminants was conducted by

Total Safety air monitoring technicians. BP’s OFFSHORE Air Monitoring Plan for Source Control, June 11,

2010 revision, was used to direct monitoring activities on the DD II and the Discoverer Enterprise. Two

technicians were assigned to the DD II and six to the Discoverer Enterprise. The technicians worked with

the vessel operators to select real‐time monitoring locations in common work areas and inside crew

quarters. In addition, technicians could place additional monitors at other locations or areas of interest

(such as the edge of the vessel or by the moon pool [an opening in the hull of the vessel giving access to

the water below]) to gain early indications of rising lower explosive limit (LEL) levels [BP 2010d]. Pictures

of the moon pools for the DD II and the Discoverer Enterprise are shown in Figures 3 and 4.

Figure 3. DD II lower moon pool.           Figure 4. Discoverer Enterprise moon pool main deck.

Airborne contaminants and atmospheric hazards monitored on the vessels by BP were: volatile organic

compounds (VOCs), LEL (calibrated for methane), percent oxygen, hydrogen sulfide (H2S), carbon

monoxide (CO), benzene, sulfur dioxide (SO2), and particulate matter less than 10 micrometers (μm)

aerodynamic diameter (PM10). These latter two contaminants were measured for source control vessels

(Discoverer Enterprise and Q4000) that were burning gas or gas and oil as part of containment or

production activities. Air monitoring for VOCs was conducted using AreaRAE Steel (Rae Systems, San

Jose, California) photo‐ionization detectors (PID). An UltraRAE (RAE Systems, San Jose, California) PID

monitor, which was specific for benzene, was used when elevated VOC levels were detected. This unit

combines an ultraviolet lamp that is energy specific for benzene with a proprietary RAE‐SepTM benzene

tube [RAE Systems 2010]. PM10 levels were obtained using stationary or portable Thermo (Thermo

Environmental Instruments, Franklin, Massachusetts) or TSI (Shoreview, Minnesota) PM10 data logging

monitors. LEL was evaluated with a catalytic bead sensor; electrochemical sensors were used to monitor

percent oxygen, H2S, and CO [BP 2010d].

4C‐4  
Personal breathing zone (PBZ) air sampling for benzene and VOCs was conducted using passive organic

vapor monitors (OVMs) that were submitted for laboratory analyses. OVM badges were placed on

personnel identified as having the highest potential for exposure [BP 2010d]. The majority of

environmental and personal exposure measurements collected on the DD II and Discoverer Enterprise

and provided to NIOSH investigators were below the lowest of the stepped BP action levels triggering

corrective measures. The lowest action levels were 50 parts per million (ppm) for VOCs, 0.5 ppm for

benzene, 25 ppm for CO, 5 ppm for H2S, 1 ppm for SO2, and 0.35 milligrams per cubic meter of air

(mg/m3

)for PM10 [BP 2010e]. Readings at these action levels triggered corrective measures that

included using water cannons to break up sheen, relocating nonessential personnel within the vessel,

donning respirators, and re‐orienting the vessel into the wind. Higher readings that exceeded the top‐

tier action levels required additional measures, e.g., moving the vessel off location (VOCs ≥ 1000 ppm;

benzene ≥10 ppm in living quarters), immediate evacuation of work area (CO ≥ 25 ppm; H2S ≥ 5 ppm),

shutdown of flaring operations (SO2 ≥ 100 ppm), and donning full‐facepiece respirators fitted with

organic vapor/acid gas/P100 cartridges (PM10 ≥ 2.5 mg/m3

). Levels of VOCs, benzene, and SO2 aboard

the Discoverer Enterprise were negligible the afternoon of June 23. PM10 values were below the action

level except for the measurement at 4:00 p.m. which was recorded at 0.278 mg/m3 [Ahrenholz 2010a].  

Airborne concentration data collected by BP and made available to NIOSH indicated that the

contaminants identified in the previous paragraph were generally low compared to OELs. Worker

exposure monitoring by BP was obtained primarily through the use of passive dosimeters. Direct reading

instrumentation was used for most of the sampling on the vessels. The active integrated sampling

conducted by NIOSH investigators sought to evaluate the primary contaminants of concern as well as

allow for analysis of additional contaminants that might be present and were compatible with the

sampling and analytical methods. Findings from other NIOSH evaluations during the Deepwater Horizon

response were used to develop the exposure assessment for these two source vessels. Information

provided by BP classifies the oil from MC252 as “light sweet crude” indicating that it is a form of

petroleum that contains exceptionally high amounts of the chemicals needed to produce gasoline,

kerosene, and high quality crude oil. The “sweet” designation describes sulfur content and that this is a

low sulfur crude oil [BP 2010f].

Evaluation

NIOSH investigators conducted PBZ and area air sampling aboard the DD II on June 21 and aboard the

Discoverer Enterprise on June 23, 2010. A BP industrial hygienist and a Transocean health, safety, and

environment advisor accompanied NIOSH investigators and helped facilitate the NIOSH evaluation.

NIOSH investigators and the BP and Transocean representatives were quantitatively fit tested for and

issued respiratory protection (half‐mask and full facepiece respirators) by a BP contractor at the Houma,

Louisiana, heliport before they were permitted to travel out to the vessels. This provided an opportunity

to observe the respirator fit testing and individual issue processes in use for all employees and visitors to

the offshore vessels.  

Both vessels were in continuous operation 24 hours per day. Workers on both vessels worked 12‐hour

shifts, either 6:00 to 6:00 or 12:00 to 12:00, depending upon whether they were part of the Marine and

Maintenance Crews or the Drill and Deck Crews. The work rotation was 2 weeks on and 2 weeks off and

NIOSH investigators were informed that the rigs would be changing to a 3 week rotation.  NIOSH

investigators asked for assistance in identifying workers whose jobs required them to spend more time

out on the deck or working in areas of the vessel that had greater potential for exposure to volatile

compounds associated with the crude oil.

4C‐5  
NIOSH investigators conducted air sampling on these vessels to help characterize exposures of workers

who were nearest to the point‐of‐release where the VOC content of the oil was expected to be greatest.

Unlike crews and cleanup workers aboard the Vessels of Opportunity, and cleanup workers onshore, the

crews of the DD II and Discoverer Enterprise were performing operations that utilized their usual and

standard  work skills, PPE, training, and experience, i.e., well drilling aboard the DD II, and storage and

processing of crude oil aboard the Discoverer Enterprise. NIOSH investigators surmised that the only

source of non‐routine occupational exposures aboard these vessels to which the crews might have been

exposed was oil on the sea surface that had been released from the blown well.  

To evaluate the presence of VOCs, NIOSH industrial hygienists conducted air sampling with (1)

multi‐sorbent thermal desorption tubes followed by thermal desorption/gas chromatography‐mass

spectrometry (NIOSH Method 2549), and (2) activated charcoal tubes (NIOSH method 1501 modified;

NIOSH method 1550). Thermal desorption tube results were used to select specific VOCs for

quantitation in PBZ and area air samples that were collected using charcoal tubes. Sulfinert®‐treated

thermal desorption tubes were used to assess the presence of sulfur compounds, e.g., sulfides. Other

compounds measured in PBZ and area air samples using integrated air sampling techniques included

propylene glycol ethers [NIOSH method 1403 modified] and polynuclear aromatic hydrocarbons (PAHs)

[NIOSH method 5506], a class of more than 100 compounds that generally occur as complex mixtures.

PAHs are formed during the incomplete combustion of coal, oil, gas, and other organic substances.  

All samples were kept cold while aboard the vessels and during shipment to the laboratory. All pumps

were calibrated before and after each sampling period.  

Direct‐reading measurements were obtained for CO and H2S. Two bulk samples of drilling mud from DD

II and four bulk samples of crude oil from the Discover Enterprise were obtained for headspace analysis

of VOCs. Initial bulk sample analyses were used to identify and confirm the presence of selected

contaminants chosen for exposure analyses prior to analyzing for specific compounds on air samples.

The bulk sample results will be included in the final NIOSH HHE report. Area sampling for diesel exhaust

particulate matter was planned; however, the sampling pump was damaged and could not be used. See

Table 1 for a complete listing of sampling and analytical methods used [NIOSH 2010a].  

All industrial hygiene equipment used on the vessels had to be certified as intrinsically safe by

Underwriters Laboratories, Inc. Because intrinsic safety certification could not be verified for the HOBO®

H8 ProSeries data logging temperature and relative humidity monitors typically used by NIOSH

investigators [Onset Computer Corporation, Bourne, Massachusetts], these instruments were not used

aboard the vessels. Weather data was obtained from the Discoverer Enterprise for June 21 and 23,

2010.

Because of concerns about possible acute health effects among workers, NIOSH industrial hygienists

distributed health symptom surveys to workers aboard both vessels. Surveys were provided to workers

who agreed to wear NIOSH air sampling equipment and take the survey. Additionally, surveys and

return envelopes were given to Transocean and BP management representatives for distribution to crew

members aboard both vessels.  Completed forms in sealed envelopes were collected by the NIOSH

industrial hygienists during the time they were present on each vessel.  

   

4C‐6  
Development Driller II

Sampling aboard DD II began at 3:00 p.m. on June 21, 2010, following mandatory in‐briefings and

orientation for the NIOSH investigators, and an opening conference with Transocean and BP

representatives. Individuals who worked outdoors on‐deck were identified and were asked to wear

sampling pumps and direct‐reading instruments. Job titles of sampled workers were roustabout (5),

floor hand (1), rotary floor foreman/lead floor hand (1), crane operator (1), and assistant driller (1). PBZ

samples were collected for the remainder of the 12:00 p.m. to 12:00 a.m. shift (437 to 491 minute

sampling period). Area samples were collected at the lower moon pool, wire line deck, well test, and at a

pipe manifold outside near the drill shack.  

  

Discoverer Enterprise  

Full‐shift PBZ air sampling was conducted throughout the 6:00 a.m. to 6:00 p.m. shift on June 23, 2010.

Individuals who worked outdoors were identified and asked to wear sampling pumps and direct‐reading

instruments. The job titles of sampled workers were well‐test field technician (1), floor hand (2), Chief

Mate (1), fire technician (2), Superintendent of ROVs (1), electrician (1), motorman (1), and air

monitoring technician (1). The full‐shift sample for the floor hand was collected on two individuals: one

was sampled from 6:00 a.m. until the end of the shift at 12:00 p.m., and the other was sampled from

12:00 p.m. on the following shift; thus, the floor hand results are reported in half‐shift segments for

each of the two floor hands. The duration of the PBZ samples was 304 to 771 minutes. Area samples

were collected at the moon pool and on the well test deck.

The normal work routine was interrupted at 8:00 a.m. due to indications that flammable gas might be

entering the riser from the blown well. Non‐essential personnel, including some sampled workers,

mustered in the galley for about 1 hour before being told to return to normal duties. The drillship was

disconnected from the blown well and was moved about 200 ft from its normal location directly above

the well, which caused flaring to cease on the Discoverer Enterprise. Transocean and BP representatives

noted that past experience indicated airborne VOC concentrations could increase approximately 3 hours

after disconnecting from the well when a larger volume of crude oil could reach the surface. The ship

was reconnected to the well, and resumed capturing oil and gas at approximately 7:50 p.m.

Results and Discussion

Table 2 contains a summary of the relevant occupational exposure limits (OELs) to which results were

compared. Note that OELs have not been established for some of the contaminants measured during

this HHE. The lack of an OEL does not necessarily mean that a substance does not have toxic properties

or interactive effects with other contaminants.

VOC screening samples were collected at the moon pools on both vessels using three‐bed thermal

desorption tubes and two‐bed Sulfinert‐treated thermal desorption tubes. Low concentrations of VOCs

were detected on both vessels. The most abundant compounds identified were C10‐C16 aliphatic

hydrocarbons. Other compounds detected in screening samples included ethylene glycol,  

2‐butoxyethanol, benzaldehyde, and phenol. Blank Sulfinert‐treated tubes contained trace amounts of

several contaminants. The ambient temperature and relative humidity (RH) was 84°F and 82% RH on

June 21, and 85°F and 82% RH on June 23, 2010.

   

4C‐7  
Development Driller II

Charcoal tube air samples obtained on DD II were quantitatively analyzed for benzene, ethyl benzene,

toluene, xylenes, limonene, naphthalene, dipropylene glycol butyl ether, dipropylene glycol methyl

ether, and total hydrocarbons (as n‐hexane). PBZ results are shown in Table 3 for four workers identified

by letters A through D. Area sample results are shown on the last page of Table 3. Airborne

concentrations of all sampled compounds were well below relevant OELs .  

Volatile Organic Compounds

Benzene, ethyl benzene, and naphthalene were not detected in PBZ or area air samples collected on

charcoal tubes on the DD II. Toluene was detected below the minimum quantifiable concentration

(MQC) in an area air sample on the wire line deck, but was not detected in any of the PBZ air samples.

Xylenes were present below the MQC in two PBZ air samples and in the area air sample on the wire line

deck. Limonene was detected below the MQC in two PBZ air samples and was not detected above the

minimum detectable concentration (MDC) in the other two PBZ air samples. Limonene was present in a

quantifiable concentration (0.032 ppm) on the wire line deck, but was not detected in the area air

sample at the pipe manifold. Limonene was below the MQC in two PBZ air samples, and not detected in

the other two PBZ air samples. Total hydrocarbons (THCs) were quantified in all PBZ and area air

samples. PBZ air samples for THCs ranged from 0.5 to 1.1 mg/m3

; the two area air samples had

concentrations of 0.16 and 9.3 mg/m3

. The highest THC concentration was measured on the wire line

deck where several other area samples found detectable or quantifiable concentrations of other

airborne compounds.

2‐Butoxyethanol and Dipropylene Glycol Ethers

NIOSH laboratory support analyzed for dipropylene glycol butyl ether, a component in COREXIT®

EC9500A [Nalco 2010], the dispersant that was injected consistently underwater near the point‐of‐

release by a nearby support vessel, Skandi Neptune, during the June 21‐23, 2010, period. Dispersant was

applied at the surface only on June 21, 2010, from 4:00 a.m. to 9:00 a.m. [Ahrenholz 2010b]. Some

disruptions in dispersant application occurred at 9:30 a.m., 1:00 p.m., and between 5:00 p.m. and 7:00

p.m. No dispersants were used or applied by workers aboard the DD II or the Discoverer Enterprise.  2‐

butoxyethanol was identified in the thermal desorption tube screening samples and was subsequently

quantified in some of the air samples.  

2‐butoxyethanol concentrations in PBZ air samples ranged from 0.029 to 0.28 ppm. The highest

concentration was quantified in the sample collected on the rotary foreman while working on the rig

floor. A review of drilling mud component material safety data sheets did not disclose any  

2‐butoxyethanol containing materials. The area air sample obtained on the wire line deck indicated 0.30

ppm; the area sample nearest to the ocean surface at the lower moon pool was below the MQC. Neither

dipropylene glycol butyl ether nor dipropylene glycol methyl ether were detected in any of the PBZ or

area air samples.

Polynuclear Aromatic Hydrocarbons

PBZ air samples were obtained for five workers (labeled as E through I in Table 3). No area air samples

were collected. Total PAHs were calculated as the sum of the peaks for the 17 individual compounds

shown in Table 3. Total PAHs values were field blank corrected. The total PAHs for each sample were

quantitated as naphthalene.

4C‐8  
Total PAHs in samples collected aboard DD II ranged from 0.0074 to 0.0096 mg/m3 of air. Naphthalene

(range: 0.00011‐0.00094 ppm), phenanthrene (range: 0.0037‐0.0074 mg/m3

), and pyrene (range:

0.00046‐0.001 mg/m3

), were quantified in all five PBZ samples.  

Fluoranthracene was quantified in the sample collected for worker G; fluorene was quantified in

samples collected for workers H and I. Acenaphthene, acenapthylene, and fluoranthracene were below

the MQC in samples collected for worker I; acenapthylene was detected below the MQC for worker F.

Fluorene was present below the MQC for worker G.  

Carbon Monoxide and Hydrogen Sulfide

The average CO concentration inside and outside the shack on the wire line deck was 1 ppm (range: 0‐6

ppm). Hydrogen sulfide was not detected in the breathing zones of the four workers who wore monitors

(workers E, F, G, and H), nor was hydrogen sulfide detected in the single area air sample collected at the

pipe manifold.  

Discoverer Enterprise

Charcoal tube air samples obtained on the Discoverer Enterprise were quantitatively analyzed for the

same compounds as described above for DD II, i.e., benzene, ethyl benzene, toluene, xylenes, limonene,

naphthalene, dipropylene glycol butyl ether, dipropylene glycol methyl ether and total hydrocarbons (as

n‐hexane). PBZ results for charcoal tube samples are shown in Table 4 for five workers (A through E).

Area air samples were obtained at the well test deck and the moon pool. Area air sample results are

shown on the last page of Table 4. Airborne concentrations of all sampled compounds were well below

relevant OELs for samples collected aboard the Discoverer Enterprise.

Volatile Organic Compounds

Benzene, ethyl benzene, and naphthalene were not detected in PBZ or area air samples collected on

charcoal tubes on the Discoverer Enterprise. Toluene and xylenes were detected below the MQC in the

PBZ air sample collected on the air monitoring technician (worker B), but were below the MDC in the

other four PBZ air samples as well as in the two area air samples. Limonene was quantified in three PBZ

air samples (workers A, B, and C), but was not detected in the other two personal samples. Limonene

was detected below the MQC on the well test deck; limonene was not detected at the moon pool. THCs

were quantified in all PBZ air samples on workers B through E, and area air samples. THCs in PBZ air

samples ranged from 0.08 to 0.42 mg/m3

; area air samples indicated THC concentrations of 0.13 at the

well test deck and 0.080 mg/m3 at the moon pool.  

2‐Butoxyethanol and Dipropylene Glycol Ethers

Quantifiable concentrations of 2‐butoxyethanol were measured in one PBZ air sample and in the area air

sample collected on the well test deck. 2 butoxyethanol in the other four PBZ air samples and in the area

air sample at the moon pool was below the MQC. Dipropylene glycol butyl ether was detected below

the MQC in PBZ air samples for workers B and C. Dipropylene glycol ethers were not detected in the

other samples.  

Polynuclear Aromatic Hydrocarbons

PBZ air samples were obtained for five workers (labeled F through J in Table 4). No PAH area air samples

were collected. Total PAHs were calculated as the sum of all peaks present in the sample. The total PAHs

for each sample were quantitated as naphthalene.

4C‐9  
Total PAHs in samples collected aboard Discoverer Enterprise ranged from 0.0048 to0.020 mg/m3

.

Naphthalene (range: 0.00026‐0.11 ppm), phenanthrene (range: 0.0025‐0.012 mg/m3

), and pyrene

(range: 0.00050‐0.0041 mg/m3

), were quantified in all five PBZ air samples.  

Fluorene was quantified in the sample collected for worker G, and was detected below the MQC in the

other four PBZ air samples. Acenapthylene was detected below the MQC in three PBZ air samples, and

chrysene was found below the MQC in one PBZ air sample.

  

Carbon Monoxide and Hydrogen Sulfide

The average CO concentration displayed by the meter worn by worker I and the meter on the well test

deck was 0 ppm (range, 0‐5 ppm). Hydrogen sulfide was not detected in the breathing zones of the four

workers who wore monitors (workers B, D, E, and J).

Observations Applicable to Both Vessels

NIOSH investigators noted two issues related to the respiratory protection program and immediately

discussed their concerns with the BP and Transocean representatives accompanying them. One issue

was with the respirator fit testing and issuance procedures at the Houma, Louisiana, heliport at the time

of the NIOSH evaluation. The use of only one manufacturer’s line of respirators to fit all personnel

presented the possibility that proper respirator fit might not be attained for some workers. Another

issue was the subsequent observation that a small number of workers on the vessels had facial hair that

could interfere with the proper seal of a respirator. Needed corrective actions were immediately noted

and corrective actions reportedly initiated by BP and Transocean representatives.  

Smoking was prohibited aboard both vessels with the exception of one designated outdoor location on

the Discoverer Enterprise. The potential for interference from tobacco smoke with the NIOSH exposure

monitoring is not considered a problem. The use of smokeless tobacco by some workers was observed

but would not affect exposure results.

Health Symptom Surveys

Twenty‐eight persons on the DDII and thirty‐four on the Discoverer Enterprise completed the health

symptom survey. Demographically, workers on these two vessels were similar (Table 5). Reported

symptoms, grouped by type, are presented in Table 6. This table includes symptoms for workers

surveyed on the two vessels and a comparison group of workers recruited at the Venice Field

Operations Branch and the Venice Commanders’ Camp who reported that they had not worked on

boats and had no exposures to oil, dispersant, cleaner, or other chemicals.

Overall, workers aboard the DDII reported a wider variety and a higher number of health symptoms

than workers from either the Discoverer Enterprise or the comparison group. Injuries and cardiovascular

symptoms were very low aboard both vessels. Headache and heat stress symptoms were reported

among workers on both vessels, while symptoms of feeling worried, stressed, and pressured were

highest among workers aboard the DDII. Thirty‐two percent of DDII workers that responded reported

feeling worried or stressed compared to 6% of the respondents on the Discoverer Enterprise and 4% of

the respondents in the comparison group.

   

4C‐10  
Summary

Exposure assessments at the source provided an opportunity to evaluate potential contaminants

associated with the oil release. Work activities on the DD II and the Discoverer Enterprise involved

operations typical of offshore oil well development and oil collection but were occurring in the context

of the explosion that killed 11 workers and released an unprecedented amount of oil into the Gulf of

Mexico.  

NIOSH investigators and others involved in the Deepwater Horizon response postulated that workers on

the source control vessels had the greatest potential for exposure to contaminants from the oil. Their

proximity to the source made them the most likely group to be exposed to the volatile crude oil

constituents released to the atmosphere above the damaged well. Additionally, conditions on the

vessels providing enclosures or conduits for chemical vapors, such as the moon pool of the Discoverer

Enterprise, could provide opportunities for increased exposure. Flares on two source vessels, one on the

Discoverer Enterprise and the other on the Q4000, created possible exposures to combustion by‐

products. Potential for worker exposure to dispersants, however, was considered to be to be less likely

than for other response workers.  

Airborne concentrations for all contaminants evaluated on the DD II and the Discoverer Enterprise were

well below (<10% and often substantially less than 10% of) applicable OELs. Although the number of

workers sampled was relatively small, samples were collected from those thought to have the greatest

exposure potential, i.e., working on open decks and directly involved with relief well drilling (DD II) or

collecting oil coming through the riser from the damaged well (Discoverer Enterprise). Although NIOSH

investigators were told that VOC levels might increase as a result of the non‐routine events on the day

of their exposure monitoring, no such increase was evident in the sampling results.  

PBZ air sampling results for nine workers on the DD II resulted in 69% (90) of the 130 analyses for

specific contaminants to be below detectable levels. Samples with detectable contamination had results

ranging from below the minimum quantifiable concentration to an amount that was quantifiable but

very low. CO and H2S concentrations were negligible (0‐6 ppm CO) or zero (CO and H2S). The four sets of

area samples reflected the same proportion of nondetectable concentrations.  

PBZ air sampling results for 10 workers on the Discoverer Enterprise resulted in 67% (94) of the 140

analyses for specific contaminants to be below detectable levels. Samples with detectable

contamination had results ranging from below the minimum quantifiable concentration to a

concentration that was quantifiable but very low. CO and H2S values were negligible (0‐6 ppm for CO) or

zero (CO and H2S). In the two sets of area samples, 75% of the 20 contaminant‐specific analyses were

below detectable levels.  

   

One issue to consider in interpreting these findings is the fact that the results are compared to OELs

unadjusted for actual work schedules. The source control vessels operated on 12 hour, 7 day per week

schedules with workers working 2 or 3 week‐long rotations. Downward adjustment of the OELs,

however, would not change the findings or determination for the days monitored due to the fact that all

exposures were very low.  

The NIOSH evaluation did not identify overexposures to contaminants that would necessitate routine

wearing of respiratory protection; however, the immediate availability of respiratory protection is

appropriate in this work environment because of the potential for an upset in operations,

4C‐11  
uncharacterized chemical releases, and sporadic releases of chemicals that may approach targeted

action levels. Continuous on‐board monitoring for contaminants of concern is a reasonable strategy for

this situation.  

Workers aboard the DD II reported more symptoms, particularly psychosocial symptoms, than workers

aboard the Discoverer Enterprise and response workers not working on vessels or with exposure to

chemical hazards. In light of the lack of evidence for significant chemical exposures, variations in rates of

physical symptoms may be related to other factors (occupational and nonoccupational) or may

represent random variation. Because heat stress symptoms were reported aboard both vessels, BP

should maintain the Deepwater Horizon Off‐shore Clean‐up Task Force Heat Stress Management Plan,

with re‐evaluation and modification as necessary based on conditions.

Thirteen workers aboard the DD II reported feeling worried, stressed, or pressured. Many contributing

factors, both occupational and non‐occupational, may have led to these responses. To determine the

specific factors for these work stress factors would require further study.  At the time of this evaluation,

oil was still leaking onto the Gulf, resulting in scrutiny and pressure to complete the relief wells as

quickly as possible.

Recommendations

Although the data collected on the days of the NIOSH evaluation did not indicate the need for

mandatory, routine respiratory protection, the practice of having respirators immediately available for

workers during uncontrolled situations or during operations where continuous area monitoring indicates

rising exposure levels should continue.

The conduct of respiratory protection fit testing and issuance of air purifying respirators at the Houma,

Louisiana, heliport, as well as their adherence to BP respiratory protection program requirements, needs

to be reassessed and corrections implemented. The ability to adequately protect workers with one

respirator line from one manufacturer is a questionable practice [OSHA 2004]. Identification and

selection of an alternate model of air purifying respirator is needed. Although this does present

challenges regarding respirator inventory and use, all workers need to be provided effective respiratory

protection.

The respirator fit testing process also provides a teachable moment for workers that should be better

utilized. Information to be covered should include limitations of respiratory protection, proper donning

and doffing procedures, indicators of the need for changing respirator cartridges, and proper storage

and cleaning of respirators. Restrictions concerning facial hair and the ability to use air purifying

respirators should be re‐iterated to all workers where the potential to use respiratory protection is

required. Although a worker may be clean‐shaven on the day he reports to a source vessel, he needs to

maintain this status over the course of the 2‐3 week work rotation aboard the vessel.

The appropriateness of applying unadjusted OELs to worker exposures obtained for 12 hour, 7 day per

week work schedules should be reevaluated for these operations. Consideration should be given to

identifying the appropriate OELs for comparing full shift exposures and for deriving action levels that

trigger additional exposure reduction measures [NIOSH 2010b].  Transition from the current 2 week

rotation to a 3 week rotation may have the potential to further complicate contaminant exposures. Ross

[2009] in his review of offshore industry shift work also notes that there may be a potential for

4C‐12  
increased severity of injuries once shifts are extended beyond 12 hours in duration or tours of duty

extended beyond the UK sector practice of 2 weeks.  

Because heat stress symptoms were reported aboard both vessels, BP should maintain the Deepwater

Horizon Off‐shore Clean‐up Task Force Heat Stress Management Plan, with re‐evaluation and

modification as necessary based on conditions.

BP and its contractors might consider a special emphasis follow‐up with regard to EAP services for the

workers on the source control, given our survey results regarding stress on the DDII.  We are aware that

BP employees always have access to BP’s EAP Hotline, and confidential counseling services whether

employees are on or off‐rotation. 

R

ACGIH [2010]. 2010 TLVs® and BEIs®: threshold limit values for chemical substances and physical agents

and biological exposure indices. Cincinnati, OH: American Conference of Governmental Industrial

Hygienists.

eferences

Ahrenholz S [2010a]. E‐mail communication of direct reading airborne contaminant levels monitored

aboard Discoverer Enterprise the afternoon of June 23, 2010 to Steven Ahrenholz, Division of

Surveillance, Hazard Evaluations, and Field Studies, National Institute for Occupational Safety and

Health, Centers for Disease Control and Prevention from Joe Gallucci, Senior Industrial Hygienist, BP

America Inc.

Ahrenholz S [2010b]. E‐mail follow‐up to conversation July 29, 2010 to Steven Ahrenholz, Division of

Surveillance, Hazard Evaluations, and Field Studies, National Institute for Occupational Safety and

Health, Centers for Disease Control and Prevention from Joe Gallucci, Senior Industrial Hygienist, and

Katie Hacker, BP NAG Industrial Hygienist, BP America Inc.  

AIHA [2010]. AIHA 2010 Emergency response planning guidelines (ERPG) & workplace environmental

exposure levels (WEEL) handbook. Fairfax, VA: American Industrial Hygiene Association.

BP [2010a]. How a relief well works.

[http://www.bp.com/genericarticle.do?categoryId=9034436&contentId=7061734]. Date accessed: July

30, 2010.

BP [2010b]. Lower marine riser package (LMRP)

cap. [http://www.bp.com/genericarticle.do?categoryId=9034436&contentId=7062491]. Date accessed:

July 30, 2010.

BP [2010c]. BP press release 16 June 2010.

[http://www.bp.com/genericarticle.do?categoryId=2012968&contentId=7062965]. Date accessed: July

30, 2010.

BP [2010d]. OFFSHORE air monitoring plan for source control. Houston, TX: BP. Unpublished. 21pgs.

BP [2010e]. OFFSHORE air monitoring plan for source control: Communication update June 12, 2010

(presentation). Houston, TX: BP Unpublished.

4C‐13  
BP [2010f]. MC 252 crude oil description and analyses. Houston, TX: BP. Unpublished.

Deepwater Horizon Unified Command [2010]. Discoverer Enterprise burns gas from damaged wellhead

in the Gulf of Mexico. http://www.deepwaterhorizonresponse.com/go/doc/2931/553811/. Date

accessed: July 30, 2010.

CFR. Code of Federal Regulations. Washington, DC: U.S. Government Printing Office, Office of the

Federal Register.

  

NIOSH [2005]. NIOSH pocket guide to chemical hazards. Cincinnati, OH: U.S. Department of Health and

Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety

and Health, DHHS (NIOSH) Publication No. 2005‐149. [http://www.cdc.gov/niosh/npg/]. Date accessed:

July 2010.

NIOSH [2010a]. NIOSH manual of analytical methods. 4th ed. Schlecht PC, O’Connor PF, eds. Cincinnati,

OH: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention,

National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 94‐113 (August

1994); 1st Supplement Publication 96‐135, 2nd Supplement Publication 98‐119, 3rd Supplement

Publication 2003‐154. [http://www.cdc.gov/niosh/docs/2003‐154/].

NIOSH [2010b]. NIOSH‐OSHA Interim guidance for protecting Deepwater Horizon response workers and

volunteers. [http://www.cdc.gov/niosh/topics/oilspillresponse/protecting/]. Date accessed: July 30,

2010.

Nalco [2010]. Material safety data sheet, COREXIT® EC9500A. Naperville, IL.: Nalco Company.

[http://www.deepwaterhorizonresponse.com/posted/2931/Corexit_EC9500A_MSDS.539287.pdf].  Date

accessed: August 3, 2010.

Net Resources International [2010]. Ship‐technology.com: Discoverer Enterprise – Drillship.

[http://www.ship‐technology.com/projects/discoverer/]. Date accessed: July 30, 2010.

OSHA [2004]. Appendix A to § 1910.134: Fit Testing Procedures.  Washington, D.C.: U.S. Department of

Labor, Occupational Safety and Health Administration.

[http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9780]. Date

accessed: July 30, 2010.

RAE  Systems [2010]. UltraRAE 3000 Portable Handheld Benzene and Compound Specific VOC Monitor.

[http://www.raesystems.com/products/ultrarae‐3000]. Date accessed: August 2, 2010.

Ross JK [2009]. Offshore industry shift work‐health and social considerations.  Occ Med 59:310‐315.

Transocean [2010a]. Fleet specifications, GSF Development Driller

II http://www.deepwater.com/fw/main/GSF‐Development‐Driller‐II‐199C77.html?LayoutID=17. Date

accessed: July 30, 2010.

Transocean [2010b]. 2010 fleet directory. http://www.deepwater.com/fw/main/Fleet‐Overview‐

273.html. Date accessed: July 30, 2010.

4C‐14  
4C‐15  

Transocean [2010c].Fleet specifications, Discoverer

Enterprise. http://www.deepwater.com/fw/main/Discoverer‐Enterprise‐61C16.html?LayoutID=17. Date

accessed: July 30, 2010.   
Table 1. Analytical methods used aboard Development Driller II and Discoverer Enterprise, June21–23,

2010

Analyte Method

Benzene NMAM† 1501‡

Carbon monoxide

Direct reading—GasAlert CO Extreme, BW Technologies

Ltd.,

Calgary, Canada

Ethyl benzene NMAM 1501‡

Glycol ethers (2‐Butoxyethanol, Dipropylene glycol

butyl ether, Dipropylene glycol methyl ether)

NMAM 1403‡

Hydrogen sulfide

Direct reading—GasAlert H2S Extreme, BW Technologies

Ltd.,

Calgary, Canada

Limonene NMAM 1501‡

Naphthalene NMAM 1501‡

Polynuclear aromatic hydrocarbons NMAM 5506

Toluene NMAM 1501‡

Total hydrocarbons NMAM 1501‡

Volatile organic compounds (Screening) NMAM 2549  

Xylenes, total NMAM 1501‡

†National Institute for Occupational Safety and Health (NIOSH) Manual of Analytical Methods [NIOSH 2010a]

‡Analysis for selected volatile organic compounds by an adaptation of the method

4C‐16  
4C‐17  

Table 2. Occupational exposure limits for substances evaluated aboard Development Driller II and

Discoverer Enterprise, June 21­23, 2010

Chemical NIOSH RELa OSHA PELb ACGIH TLVc AIHA WEELd

Benzene 0.1 ppm TWAe

1 ppm STELf

1 ppm TWA

5 ppm STEL

0.5 ppm Action

Level

0.5 ppm TWA

2.5 ppm STEL

N/Ag

2‐Butoxyethanol 5 ppm TWA 50 ppm TWA 20 ppm TWA N/A

Carbon monoxide 35 ppm TWA

200 ppm

Ceiling

50 ppm TWA 25 ppm TWA N/A

Dipropylene glycol butyl ether N/A N/A N/A N/A

Dipropylene glycol methyl ether 100 ppm TWA

150 ppm STEL

100 ppm TWA 100 ppm TWA

150 ppm STEL

N/A

Ethyl benzene 100 ppm TWA

125 ppm STEL

100 ppm TWA 100 ppm TWAh

125 ppm STEL

N/A

Hydrogen sulfide 10 ppm Ceiling

(10 min max)

20 ppm Ceilingi 1 ppm TWA

5 ppm STEL

N/A

Limonene N/A N/A N/A 30 ppm TWA

Naphthalene 10 ppm TWA

15 ppm STEL

10 ppm TWA 10 ppm TWA

15 ppm STEL

N/A

Polynuclear Aromatic Hydrocarbons    N/Aj N/A j N/A j N/A

Total hydrocarbons 350 mg/m3

TWA

1800 mg/m3

Ceiling

(Petroleum

distillates)

2000 mg/m3

TWA

(Petroleum

distillates as

naphtha)

200 mg/m3

TWA

(Kerosene as

total

hydrocarbon

vapor)

N/A

Toluene 100 ppm TWA

150 ppm STEL

200 ppm TWA

300 ppm

Ceiling

500 ppm Peak

(10 min max)

20 ppm TWA N/A

Xylenes 100 ppm TWA

150 ppm STEL

100 ppm TWA 100 ppm TWA

150 ppm STEL

N/A

a

National Institute for Occupational Safety and Health (NIOSH) recommended exposure limit (REL) [NIOSH 2005] b

Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) [29 CFR 1910] c

American Conference of Governmental Industrial Hygienists® (ACGIH) threshold limit value® (TLV) [ACGIH 2010] d

American Industrial Hygiene Association (AIHA) Workplace Environmental Exposure Level (WEEL) [AIHA 2010] e

TWA = time weighted average f

STEL = short term exposure limit g

N/A = not applicable h

Proposed to be changed to 20 ppm TWA and STEL eliminated [ACGIH 2010] i

Exposures shall not exceed with the following exception: if no other measurable exposure occurs during the 8‐hour

work shift, exposures may exceed 20 ppm, but not more than 50 ppm (peak), for a single time period up to 10 minutes

j

With the exception of naphthalene, OELs are not available for the individual PAHs measured in this evaluation.  

   
4C‐18  

Table 3. Personal breathing zone and area air concentrations for substances measured on June 21,

2010 on the DDII

Activity/Location Substance

Sampling

Information* Sample Concentration†‡ Time

(min)

Volume

(Liters)

Personal Breathing Zone Air Samples—Worker A

Roustabout, Main Deck Benzene 442 45.5 <0.001 ppm

Roustabout, Main Deck 2‐Butoxyethanol 445 86.3 0.065 ppm

Roustabout, Main Deck Dipropylene glycol

butyl ether

445 86.3 <0.0007 ppm

Roustabout, Main Deck Dipropylene glycol

methyl ether

445 86.3 <0.0004 ppm

Roustabout, Main Deck Ethyl benzene 442 45.5 <0.001 ppm

Roustabout, Main Deck Limonene 442 45.5 (0.0010 ppm)

Roustabout, Main Deck Naphthalene 442 45.5 <0.0008 ppm

Roustabout, Main Deck Toluene 442 45.5 <0.001 ppm

Roustabout, Main Deck Total hydrocarbons 442 45.5 0.66 mg/m3

Roustabout, Main Deck Xylenes 442 45.5 (0.0031 ppm)

Personal Breathing Zone Air Samples—Worker B

Rotary Foreman/Lead Floor

Hand, Rig Floor

Benzene 457 48.5 <0.001 ppm

Rotary Foreman/Lead Floor

Hand, Rig Floor

2‐Butoxyethanol 460 48.0 0.28 ppm

Rotary Foreman/Lead Floor

Hand, Rig Floor

Dipropylene glycol

butyl ether

460 48.0 <0.001 ppm

Rotary Foreman/Lead Floor

Hand, Rig Floor

Dipropylene glycol

methyl ether

460 48.0 <0.0007 ppm

Rotary Foreman/Lead Floor

Hand, Rig Floor

Ethyl benzene 457 48.5 <0.0009 ppm

Rotary Foreman/Lead Floor

Hand, Rig Floor

Limonene 457 48.5 <0.0007 ppm

Rotary Foreman/Lead Floor

Hand, Rig Floor

Naphthalene 457 48.5 <0.0008 ppm

Rotary Foreman/Lead Floor

Hand, Rig Floor

Toluene 457 48.5 <0.001 ppm

Rotary Foreman/Lead Floor

Hand, Rig Floor

Total hydrocarbons 457 48.5 1.1 mg/m3

Rotary Foreman/Lead Floor

Hand, Rig Floor

Xylenes 457 48.5 <0.002 ppm

   
4C‐19  

Table 3. Personal breathing zone and area air concentrations for substances measured on June 21, 2010

on the DDII (continued)

Activity/Location Substance

Sampling

Information* Sample Concentration†‡ Time

(min)

Volume

(Liters)

Personal Air Samples—Worker C

Roustabout, Main Deck Benzene 451 47.5 <0.001 ppm

Roustabout, Main Deck 2‐Butoxyethanol 450 47.9 0.082 ppm

Roustabout, Main Deck Dipropylene glycol

butyl ether

450 47.9 <0.001 ppm

Roustabout, Main Deck Dipropylene glycol

methyl ether

450 47.9 <0.0007 ppm

Roustabout, Main Deck Ethyl benzene 451 47.5 <0.001 ppm

Roustabout, Main Deck Limonene 451 47.5 <0.0008 ppm

Roustabout, Main Deck Naphthalene 451 47.5 <0.0008 ppm

Roustabout, Main Deck Toluene 451 47.5 <0.001 ppm

Roustabout, Main Deck Total hydrocarbons 451 47.5 0.50 mg/m3

Roustabout, Main Deck Xylenes 451 47.5 (0.0026 ppm)

Personal Air Samples—Worker D

Floor Hand, Rig Floor Benzene 461 48.8 <0.001 ppm

Floor Hand, Rig Floor 2‐Butoxyethanol 461 48.3 0.029 ppm

Floor Hand, Rig Floor Dipropylene glycol

butyl ether

461 48.3 <0.001 ppm

Floor Hand, Rig Floor Dipropylene glycol

methyl ether

461 48.3 <0.0007 ppm

Floor Hand, Rig Floor Ethyl benzene 461 48.8 <0.0009 ppm

Floor Hand, Rig Floor Limonene 461 48.8 (0.015 ppm)

Floor Hand, Rig Floor Naphthalene 461 48.8 <0.0008 ppm

Floor Hand, Rig Floor Toluene 461 48.8 <0.001 ppm

Floor Hand, Rig Floor Total hydrocarbons 461 48.8 1.1 mg/m3

Floor Hand, Rig Floor Xylenes 461 48.8 <0.002 ppm

Personal Air Samples—Worker E

Roustabout, Main Deck Acenaphthene 468 935 <0.0001 mg/m3

Roustabout Acenapthylene 468 935 <0.0001 mg/m3

Roustabout Anthracene 468 935 <0.0001 mg/m3

Roustabout Benzo(a)anthracene 468 935 <0.0002 mg/m3

Roustabout Benzo(a)pyrene 468 935 <0.0003 mg/m3

Roustabout Benzo(b)fluoranthene 468 935 <0.0001 mg/m3

Roustabout Benzo(e)pyrene 468 935 <0.0002 mg/m3

Roustabout Benzo(g,h,i)perylene 468 935 <0.0002 mg/m3

Roustabout, Main Deck Benzo(k)fluoranthene 468 935 <0.0001 mg/m3

Roustabout, Main Deck Chrysene 468 935 <0.0001 mg/m3

Roustabout, Main Deck Dibenzo(a,h)anthracene 468 935 <0.0001 mg/m3

Roustabout, Main Deck Fluoranthracene 468 935 <0.0001 mg/m3

Roustabout, Main Deck Fluorene 468 935 <0.0001 mg/m3

Roustabout, Main Deck Hydrogen sulfide 493 N/A 0 ppm

Roustabout, Main Deck Indeno(1,2,3‐cd)pyrene 468 935 <0.0002 mg/m3

Roustabout, Main Deck Naphthalene 468 935 0.000094 ppm
4C‐20  

Table 3. Personal breathing zone and area air concentrations for substances measured on June 21, 2010

on the DDII (continued)

Activity/Location Substance

Sampling

Information* Sample Concentration†‡ Time

(min)

Volume

(Liters)

Personal Air Samples—Worker E (continued)

Roustabout, Main Deck Phenanthrene 468 935 0.0042 mg/m3

Roustabout, Main Deck Pyrene 468 935 0.00046 mg/m3

Roustabout, Main Deck Total PAHs 468 935 0.0074 mg/m3

Personal Air Samples—Worker F

Crane Operator, Starboard

Crane

Acenaphthene 437 875 <0.00006 mg/m3

Crane Operator, Starboard

Crane

Acenapthylene 437 875 (0.00014 mg/m3)

Crane Operator, Starboard

Crane

Anthracene 437 875 <0.00006 mg/m3

Crane Operator, Starboard

Crane

Benzo(a)anthracene 437 875 <0.00009 mg/m3

Crane Operator, Starboard

Crane

Benzo(a)pyrene 437 875 <0.0002 mg/m3

Crane Operator, Starboard

Crane

Benzo(b)fluoranthene 437 875 <0.00006 mg/m3

Crane Operator, Starboard

Crane

Benzo(e)pyrene 437 875 <0.0001 mg/m3

Crane Operator, Starboard

Crane

Benzo(g,h,i)perylene 437 875 <0.0001 mg/m3

Crane Operator, Starboard

Crane

Benzo(k)fluoranthene 437 875 <0.00007 mg/m3

Crane Operator, Starboard

Crane

Chrysene 437 875 <0.00009 mg/m3

Crane Operator, Starboard

Crane

Dibenzo(a,h)anthracene 437 875 <0.00007 mg/m3

Crane Operator, Starboard

Crane

Fluoranthracene 437 875 <0.00007 mg/m3

Crane Operator, Starboard

Crane

Fluorene 437 875 0.00027 mg/m3

Crane Operator, Starboard

Crane

Hydrogen sulfide 487 N/A 0 ppm

Crane Operator, Starboard

Crane

Indeno(1,2,3‐cd)pyrene 437 875 <0.0001 mg/m3

Crane Operator, Starboard

Crane

Naphthalene 437 875 0.00013 ppm

Crane Operator, Starboard

Crane

Phenanthrene 437 875 0.0037 mg/m3

Crane Operator, Starboard

Crane

Pyrene 437 875 0.00053 mg/m3

Crane Operator, Starboard

Crane

Total PAHs 437 875 0.0081 mg/m3

   
4C‐21  

Table 3. Personal breathing zone and area air concentrations for substances measured on June 21, 2010

on the DDII (continued)

Activity/Location Substance

Sampling

Information* Sample Concentration†‡ Time

(min)

Volume

(Liters)

Personal Air Samples—Worker G

Roustabout, Main Deck Acenaphthene 444 879 <0.0001 mg/m3

Roustabout, Main Deck Acenapthylene 444 879 <0.0001 mg/m3

Roustabout, Main Deck Anthracene 444 879 <0.0001 mg/m3

Roustabout, Main Deck Benzo(a)anthracene 444 879 <0.0002 mg/m3

Roustabout, Main Deck Benzo(a)pyrene 444 879 <0.0003 mg/m3

Roustabout, Main Deck Benzo(b)fluoranthene 444 879 <0.0001 mg/m3

Roustabout, Main Deck Benzo(e)pyrene 444 879 <0.0002 mg/m3

Roustabout, Main Deck Benzo(g,h,i)perylene 444 879 <0.0002 mg/m3

Roustabout, Main Deck Benzo(k)fluoranthene 444 879 <0.0001 mg/m3

Roustabout, Main Deck Chrysene 444 879 <0.0001 mg/m3

Roustabout, Main Deck Dibenzo(a,h)anthracene 444 879 <0.0001 mg/m3

Roustabout, Main Deck Fluoranthracene 444 879 0.00014 mg/m3

Roustabout, Main Deck Fluorene 444 879 (0.00017 mg/m3)

Roustabout, Main Deck Hydrogen sulfide 473 N/A 0 ppm

Roustabout, Main Deck Indeno(1,2,3‐cd)pyrene 444 879 <0.0002 mg/m3

Roustabout, Main Deck Naphthalene 444 879 0.00014 ppm

Roustabout, Main Deck Phenanthrene 444 879 0.0043 mg/m3

Roustabout, Main Deck Pyrene 444 879 0.0010 mg/m3

Roustabout, Main Deck Total PAHs 444 879 0.0096 mg/m3

Personal Air Samples—Worker H

Roustabout, Main Deck Acenaphthene 491 972 <0.0001 mg/m3

Roustabout, Main Deck Acenapthylene 491 972 <0.00009 mg/m3

Roustabout, Main Deck Anthracene 491 972 <0.0001 mg/m3

Roustabout, Main Deck Benzo(a)anthracene 491 972 <0.0002 mg/m3

Roustabout, Main Deck Benzo(a)pyrene 491 972 <0.0003 mg/m3

Roustabout, Main Deck Benzo(b)fluoranthene 491 972 <0.0001 mg/m3

Roustabout, Main Deck Benzo(e)pyrene 491 972 <0.0002 mg/m3

Roustabout, Main Deck Benzo(g,h,i)perylene 491 972 <0.0002 mg/m3

Roustabout, Main Deck Benzo(k)fluoranthene 491 972 <0.0001 mg/m3

Roustabout, Main Deck Chrysene 491 972 <0.0001 mg/m3

Roustabout, Main Deck Dibenzo(a,h)anthracene 491 972 <0.0001 mg/m3

Roustabout, Main Deck Fluoranthracene 491 972 <0.0001 mg/m3

Roustabout, Main Deck Fluorene 491 972 0.00039 mg/m3

Roustabout, Main Deck Hydrogen Sulfide 508 N/A 0 ppm

Roustabout, Main Deck Indeno(1,2,3‐cd)pyrene 491 972 <0.0002 mg/m3

Roustabout, Main Deck Naphthalene 491 972 0.00011 ppm

Roustabout, Main Deck Phenanthrene 491 972 0.0074 mg/m3

Roustabout, Main Deck Pyrene 491 972 0.00084 mg/m3

Roustabout, Main Deck Total PAHs 491 972 0.0083 mg/m3

Personal Air Samples—Worker I

Assistant Driller/Rig Floor Acenaphthene 468 931 (0.00015 mg/m3)

Assistant Driller/Rig Floor Acenapthylene 468 931 (0.00014 mg/m3)
4C‐22  

Table 3. Personal breathing zone and area air concentrations for substances measured on June 21, 2010

on the DDII (continued)

Activity/Location Substance

Sampling

Information* Sample Concentration†‡ Time

(min)

Volume

(Liters)

Personal Air Samples—Worker I(continued)

Assistant Driller/Rig Floor Anthracene 468 931 <0.0001 mg/m3

Assistant Driller/Rig Floor Benzo(a)anthracene 468 931 <0.0002 mg/m3

Assistant Driller/Rig Floor Benzo(a)pyrene 468 931 <0.0003 mg/m3

Assistant Driller/Rig Floor Benzo(b)fluoranthene 468 931 <0.0001 mg/m3

Assistant Driller/Rig Floor Benzo(e)pyrene 468 931 <0.0002 mg/m3

Assistant Driller/Rig Floor Benzo(g,h,i)perylene 468 931 <0.0002 mg/m3

Assistant Driller/Rig Floor Benzo(k)fluoranthene 468 931 <0.0001 mg/m3

Assistant Driller/Rig Floor Chrysene 468 931 <0.0001 mg/m3

Assistant Driller/Rig Floor Dibenzo(a,h)anthracene 468 931 <0.0001 mg/m3

Assistant Driller/Rig Floor Fluoranthracene 468 931 (0.00013 mg/m3)

Assistant Driller/Rig Floor Fluorene 468 931 0.00019 mg/m3

Assistant Driller/Rig Floor Indeno(1,2,3‐cd)pyrene 468 931 <0.0002 mg/m3

Assistant Driller/Rig Floor Naphthalene 468 931 0.00021 ppm

Assistant Driller/Rig Floor Phenanthrene 468 931 0.0041 mg/m3

Assistant Driller/Rig Floor Pyrene 468 931 0.00069 mg/m3

Assistant Driller/Rig Floor Total PAHs 468 931 0.0088 mg/m3

Area Air Samples

Wire Line Deck 4th Level Benzene 467 49.3 <0.001 ppm

Pipe Manifold Benzene 372 19.8 <0.003 ppm

Wire Line Deck 4th Level 2‐Butoxyethanol 470 49.4 0.30 ppm

Lower Moon Pool Fore

Side

2‐Butoxyethanol 183 9.74 (0.0062 ppm)

Rig Level 4 Wire Line –

Outside Shack Door

Carbon Monoxide 460 N/A Range: 0–6 ppm; Avg: 1 ppm

Rig Level 4 Wire Line –

Inside Shack Over

Workstation

Carbon Monoxide 465 N/A Range: 0–6 ppm; Avg: 1 ppm

Wire Line Deck 4th Level Dipropylene glycol butyl

ether

470 49.4 <0.001 ppm

Lower Moon Pool Fore

Side

Dipropylene glycol butyl

ether

183 9.74 <0.007 ppm

Wire Line Deck 4th Level Dipropylene glycol methyl

ether

470 49.4 <0.0007 ppm

Lower Moon Pool Fore

Side

Dipropylene glycol methyl

ether

183 9.74 <0.003 ppm

Wire Line Deck 4th Level Ethyl benzene 467 49.3 <0.0009 ppm

Pipe Manifold Ethyl benzene 372 19.8 <0.002 ppm

Pipe Manifold Hydrogen sulfide 411 N/A 0 ppm

Wire Line Deck 4th Level Limonene 467 49.3 0.032  

Pipe Manifold Limonene 372 19.8 <0.002 ppm

   
4C‐23  

Table 3. Personal breathing zone and area air concentrations for substances measured on June 21, 2010

on the DDII (continued)

Activity/Location Substance

Sampling

Information* Sample Concentration†‡ Time

(min)

Volume

(Liters)

Area Air Samples (continued)

Wire Line Deck 4th Level Naphthalene 467 49.3 <0.0008 ppm

Pipe Manifold Naphthalene 372 19.8 <0.002 ppm

Wire Line Deck 4th Level Toluene 467 49.3 (0.0012 ppm)

Pipe Manifold Toluene 372 19.8 <0.003 ppm

Wire Line Deck 4th Level Total hydrocarbons 467 49.3 9.3 mg/m3

Pipe Manifold Total hydrocarbons 372 19.8 0.16 mg/m3

Wire Line Deck 4th Level Xylenes 467 49.3 (0.0040 ppm)

Pipe Manifold Xylenes 372 19.8 <0.005 ppm

*N/A = not applicable

†Concentrations reported as “<” were not detected; the given value is the minimum detectable concentration

‡Concentrations in parentheses were between the minimum detectable concentration and the minimum quantifiable

concentration (parentheses are used to point out there is more uncertainty associated with these values than values above

the minimum quantifiable concentration)

   
4C‐24  

Table 4. Personal breathing zone and area air concentrations for substances measured on June 23,

2010 on the Discoverer Enterprise

Activity/Location Substance

Sampling

Information* Sample Concentration†‡ Time

(min)

Volume

(Liters)

Personal Breathing Zone Air Samples—Worker A

Fire Technician, Main Deck Benzene 592 59.3 <0.002 ppm

Fire Technician, Main Deck 2‐Butoxyethanol 591 59.4 (0.0016 ppm)

Fire Technician, Main Deck Dipropylene glycol

butyl ether

591 59.4 <0.002 ppm

Fire Technician, Main Deck Dipropylene glycol

methyl ether

591 59.4 <0.001 ppm

Fire Technician, Main Deck Ethyl benzene 592 59.3 <0.002 ppm

Fire Technician, Main Deck Limonene 592 59.3 0.0044 ppm

Fire Technician, Main Deck Naphthalene 592 59.3 <0.001 ppm

Fire Technician, Main Deck Toluene 592 59.3 <0.002 ppm

Fire Technician, Main Deck Total hydrocarbons 592 59.3 0.25 mg/m3

Fire Technician, Main Deck Xylenes 592 59.3 <0.003 ppm

Personal Breathing Zone Air Samples—Worker B

Air Monitor Technician Benzene 690 69.1 <0.002 ppm

Air Monitor Technician 2‐Butoxyethanol 694 69.5 (0.0022 ppm)

Air Monitor Technician Dipropylene glycol

butyl ether

694 69.5 (0.0024 ppm)

Air Monitor Technician Dipropylene glycol

methyl ether

694 69.5 <0.001 ppm

Air Monitor Technician Ethyl benzene 690 69.1 <0.001 ppm

Air Monitor Technician Hydrogen sulfide 704 N/A 0 ppm

Air Monitor Technician Limonene 690 69.1 0.0038 ppm

Air Monitor Technician Naphthalene 690 69.1 <0.001 ppm

Air Monitor Technician Toluene 690 69.1 (0.0026 ppm)

Air Monitor Technician Total hydrocarbons 690 69.1 0.42 mg/m3

Air Monitor Technician Xylenes 690 69.1 (0.0030 ppm)

Personal Air Samples—Worker C

Well Test Field Tech,

Production Deck  

Benzene 765 76.3 <0.002 ppm

Well Test Field Tech,

Production Deck

2‐Butoxyethanol 759 75.7 (0.0015 ppm)

Well Test Field Tech,

Production Deck  

Dipropylene glycol

butyl ether

759 75.7 (0.0017 ppm)

Well Test Field Tech,

Production Deck  

Dipropylene glycol

methyl ether

759 75.7 <0.0009 ppm

Well Test Field Tech,

Production Deck  

Ethyl benzene 765 76.3 <0.001 ppm

Well Test Field Tech,

Production Deck  

Hydrogen sulfide 757 N/A 0 ppm

Well Test Field Tech,

Production Deck  

Limonene 765 76.3 0.0097 ppm

   
4C‐25  

Table 4. Personal breathing zone and area air concentrations for substances measured on June 23, 2010

on the Discoverer Enterprise (continued)

Activity/Location Substance

Sampling

Information* Sample Concentration†‡ Time

(min)

Volume

(Liters)

Personal Air Samples—Worker C (continued)

Well Test Field Tech,

Production Deck  

Naphthalene 765 76.3 <0.001 ppm

Well Test Field Tech,

Production Deck  

Toluene 765 76.3 <0.001 ppm

Well Test Field Tech,

Production Deck  

Total hydrocarbons 765 76.3 0.30 mg/m3

Well Test Field Tech,

Production Deck  

Xylenes 765 76.3 <0.001 ppm

Personal Air Samples—Worker D

Floor Hand, Rig Floor Benzene 351 34.9 <0.002 ppm

Floor Hand, Rig Floor 2‐Butoxyethanol 357 35.9 (0.0014 ppm)

Floor Hand, Rig Floor Dipropylene glycol

butyl ether

357 35.9 <0.002 ppm

Floor Hand, Rig Floor Dipropylene glycol

methyl ether

357 35.9 <0.0009 ppm

Floor Hand, Rig Floor Ethyl benzene 351 34.9 <0.001 ppm

Floor Hand, Rig Floor Hydrogen sulfide 351 N/A 0 ppm

Floor Hand, Rig Floor Limonene 351 34.9 <0.001 ppm

Floor Hand, Rig Floor Naphthalene 351 34.9 <0.001 ppm

Floor Hand, Rig Floor Toluene 351 34.9 <0.002 ppm

Floor Hand, Rig Floor Total hydrocarbons 351 34.9 0.12 mg/m3

Floor Hand, Rig Floor Xylenes 351 34.9 <0.003 ppm

Personal Air Samples—Worker E

Floor Hand, Rig Floor Benzene 304 30.2 <0.002 ppm

Floor Hand, Rig Floor 2‐Butoxyethanol 306 30.8 0.032 ppm

Floor Hand, Rig Floor Dipropylene glycol

butyl ether

306 30.8 <0.002 ppm

Floor Hand, Rig Floor Dipropylene glycol

methyl ether

306 30.8 <0.001 ppm

Floor Hand, Rig Floor Ethyl benzene 304 30.2 <0.002 ppm

Floor Hand, Rig Floor Hydrogen sulfide 304 N/A 0 ppm

Floor Hand, Rig Floor Limonene 304 30.2 <0.001 ppm

Floor Hand, Rig Floor Naphthalene 304 30.2 <0.001 ppm

Floor Hand, Rig Floor Toluene 304 30.2 <0.002 ppm

Floor Hand, Rig Floor Total hydrocarbons 304 30.2 0.08 mg/m3

Floor Hand, Rig Floor Xylenes 304 30.2 <0.003 ppm

Personal Air Samples—Worker F

Chief Mate, Cargo Deck Acenaphthene 771 1550 <0.00006 mg/m3

Chief Mate, Cargo Deck Acenapthylene 771 1550 (0.000058 mg/m3)

Chief Mate, Cargo Deck Anthracene 771 1550 <0.00006 mg/m3

Chief Mate, Cargo Deck Benzo(a)anthracene 771 1550 <0.0001 mg/m3

Chief Mate, Cargo Deck Benzo(a)pyrene 771 1550 <0.0002 mg/m3

   
4C‐26  

Table 4. Personal breathing zone and area air concentrations for substances measured on June 23, 2010

on the Discoverer Enterprise (continued)

Activity/Location Substance

Sampling

Information* Sample Concentration†‡ Time

(min)

Volume

(Liters)

Personal Air Samples—Worker F (continued)

Chief Mate, Cargo Deck Benzo(b)fluoranthene 771 1550 <0.00006 mg/m3

Chief Mate, Cargo Deck Benzo(e)pyrene 771 1550 <0.0001 mg/m3

Chief Mate, Cargo Deck Benzo(g,h,i)perylene 771 1550 <0.0001 mg/m3

Chief Mate, Cargo Deck Benzo(k)fluoranthene 771 1550 <0.00007 mg/m3

Chief Mate, Cargo Deck Chrysene 771 1550 <0.00008 mg/m3

Chief Mate, Cargo Deck Dibenzo(a,h)anthracene 771 1550 <0.00007 mg/m3

Chief Mate, Cargo Deck Fluoranthracene 771 1550 <0.00008 mg/m3

Chief Mate, Cargo Deck Fluorene 771 1550 (0.00020 mg/m3)

Chief Mate, Cargo Deck Indeno(1,2,3‐cd)pyrene 771 1550 <0.0001 mg/m3

Chief Mate, Cargo Deck Naphthalene 771 1550 0.00028 ppm

Chief Mate, Cargo Deck Phenanthrene 771 1550 0.0059 mg/m3

Chief Mate, Cargo Deck Pyrene 771 1550 0.00084 mg/m3

Chief Mate, Cargo Deck Total PAHs 771 1550 0.012 mg/m3

Personal Air Samples—Worker G

Fire Technician Acenaphthene 723 1450 <0.00007 mg/m3

Fire Technician Acenapthylene 723 1450 (0.000083 mg/m3)

Fire Technician Anthracene 723 1450 <0.00007 mg/m3

Fire Technician Benzo(a)anthracene 723 1450 <0.0001 mg/m3

Fire Technician Benzo(a)pyrene 723 1450 <0.0002 mg/m3

Fire Technician Benzo(b)fluoranthene 723 1450 <0.00007 mg/m3

Fire Technician Benzo(e)pyrene 723 1450 <0.0001 mg/m3

Fire Technician Benzo(b)fluoranthene 723 1450 <0.00007 mg/m3

Fire Technician Benzo(e)pyrene 723 1450 <0.0001 mg/m3

Fire Technician Benzo(g,h,i)perylene 723 1450 <0.0001 mg/m3

Fire Technician Benzo(k)fluoranthene 723 1450 <0.00008 mg/m3

Fire Technician Chrysene 723 1450 <0.00009 mg/m3

Fire Technician Dibenzo(a,h)anthracene 723 1450 <0.00008 mg/m3

Fire Technician Fluoranthracene 723 1450 <0.00008 mg/m3

Fire Technician Fluorene 723 1450 0.00027 mg/m3

Fire Technician Indeno(1,2,3‐cd)pyrene 723 1450 <0.0001 mg/m3

Fire Technician Naphthalene 723 1450 0.11 ppm

Fire Technician Phenanthrene 723 1450 0.0025 mg/m3

Fire Technician Pyrene 723 1450 0.00050 mg/m3

Fire Technician Total PAHs 723 1450 0.0048 mg/m3

   
4C‐27  

Table 4. Personal breathing zone and area air concentrations for substances measured on June 23, 2010

on the Discoverer Enterprise (continued)

Activity/Location Substance

Sampling

Information* Sample Concentration†‡ Time

(min)

Volume

(Liters)

Personal Air Samples—Worker H

Superintendant of ROV,

Midship

Acenaphthene 713 1420 <0.00007 mg/m3

Superintendant of ROV,

Midship

Acenapthylene 713 1420 (0.000085 mg/m3)

Superintendant of ROV,

Midship

Anthracene 713 1420 <0.00007 mg/m3

Superintendant of ROV,

Midship

Benzo(a)anthracene 713 1420 <0.0001 mg/m3

Superintendant of ROV,

Midship

Benzo(a)pyrene 713 1420 <0.0002 mg/m3

Superintendant of ROV,

Midship

Benzo(b)fluoranthene 713 1420 <0.00007 mg/m3

Superintendant of ROV,

Midship

Benzo(e)pyrene 713 1420 <0.0001 mg/m3

Superintendant of ROV,

Midship

Benzo(g,h,i)perylene 713 1420 <0.0001 mg/m3

Superintendant of ROV,

Midship

Benzo(k)fluoranthene 713 1420 <0.00008 mg/m3

Superintendant of ROV,

Midship

Chrysene 713 1420 <0.00009 mg/m3

Superintendant of ROV,

Midship

Dibenzo(a,h)anthracene 713 1420 <0.00008 mg/m3

Superintendant of ROV,

Midship

Fluoranthracene 713 1420 0.000085 mg/m3

Superintendant of ROV,

Midship

Fluorene 713 1420 (0.00016 mg/m3)

Superintendant of ROV,

Midship

Indeno(1,2,3‐cd)pyrene 713 1420 <0.0001 mg/m3

Superintendant of ROV,

Midship

Naphthalene 713 1420 0.00039 ppm

Superintendant of ROV,

Midship

Phenanthrene 713 1420 0.0055 mg/m3

Superintendant of ROV,

Midship

Pyrene 713 1420 0.00092 mg/m3

Superintendant of ROV,

Midship

Total PAHs 713 1420 0.014 mg/m3

Personal Air Samples—Worker I

Electrician Acenaphthene 698 1410 <0.00007 mg/m3

Electrician Acenapthylene 698 1410 <0.00006 mg/m3

Electrician Anthracene 698 1410 <0.00007 mg/m3

Electrician Benzo(a)anthracene 698 1410 <0.0001 mg/m3

   
4C‐28  

Table 4. Personal breathing zone and area air concentrations for substances measured on June 23, 2010

on the Discoverer Enterprise (continued)

Activity/Location Substance

Sampling

Information* Sample Concentration†‡ Time

(min)

Volume

(Liters)

Personal Air Samples—Worker I (continued)

Electrician Benzo(a)pyrene 698 1410 <0.0002 mg/m3

Electrician Benzo(b)fluoranthene 698 1410 <0.00007 mg/m3

Electrician Benzo(e)pyrene 698 1410 <0.0001 mg/m3

Electrician Benzo(g,h,i)perylene 698 1410 <0.0001 mg/m3

Electrician Benzo(k)fluoranthene 698 1410 <0.00008 mg/m3

Electrician Carbon Monoxide 696 N/A Range: 0–5 ppm; Avg: 0 ppm

Electrician Chrysene 698 1410 (0.00041 mg/m3)

Electrician Dibenzo(a,h)anthracene 698 1410 <0.00008 mg/m3

Electrician Fluoranthracene 698 1410 <0.00009 mg/m3

Electrician Fluorene 698 1410 (0.00018 mg/m3)

Electrician Indeno(1,2,3‐cd)pyrene 698 1410 <0.0001 mg/m3

Electrician Naphthalene 698 1410 0.00026 ppm

Electrician Phenanthrene 698 1410 0.0071 mg/m3

Electrician Pyrene 698 1410 0.0016 mg/m3

Electrician Total PAHs 698 1410 0.014 mg/m3

Personal Air Samples—Worker J

Motorman, Lower Machine

Deck

Acenaphthene 574 1160 <0.00009 mg/m3

Motorman, Lower Machine

Deck

Acenapthylene 574 1160 <0.00008 mg/m3

Motorman, Lower Machine

Deck

Anthracene 574 1160 <0.00009 mg/m3

Motorman, Lower Machine

Deck

Benzo(a)anthracene 574 1160 <0.0001 mg/m3

Motorman, Lower Machine

Deck

Benzo(a)pyrene 574 1160 <0.0003 mg/m3

Motorman, Lower Machine

Deck

Benzo(b)fluoranthene 574 1160 <0.00009 mg/m3

Motorman, Lower Machine

Deck

Benzo(e)pyrene 574 1160 <0.0001 mg/m3

Motorman, Lower Machine

Deck

Benzo(g,h,i)perylene 574 1160 <0.0001 mg/m3

Motorman, Lower Machine

Deck

Benzo(k)fluoranthene 574 1160 <0.00009 mg/m3

Motorman, Lower Machine

Deck

Chrysene 574 1160 <0.0001 mg/m3

Motorman, Lower Machine

Deck

Dibenzo(a,h)anthracene 574 1160 <0.00009 mg/m3

Motorman, Lower Machine

Deck

Fluoranthracene 574 1160 <0.0001 mg/m3

Motorman, Lower Machine

Deck

Fluorene 574 1160 (0.00019 mg/m3)

   
4C‐29  

Table 4. Personal breathing zone and area air concentrations for substances measured on June 23, 2010

on the Discoverer Enterprise (continued)

Activity/Location Substance

Sampling

Information* Sample Concentration†‡ Time

(min)

Volume

(Liters)

Personal Air Samples—Worker J (continued)

Motorman, Lower Machine

Deck

Hydrogen sulfide 654 N/A 0 ppm

Motorman, Lower Machine

Deck

Indeno(1,2,3‐cd)pyrene 574 1160 <0.0001 mg/m3

Motorman, Lower Machine

Deck

Naphthalene 574 1160 0.00026 ppm

Motorman, Lower Machine

Deck

Phenanthrene 574 1160 0.012 mg/m3

Motorman, Lower Machine

Deck

Pyrene 574 1160 0.0041 mg/m3

Motorman, Lower Machine

Deck

Total PAHs 574 1160 0.020 mg/m3

Area Air Samples

Well Test Deck Benzene 751 75.6 <0.0008 ppm

Moon Pool Benzene 224 22.5 <0.003 ppm

Well Test Deck 2‐Butoxyethanol 751 74.9 0.0026 ppm

Moon Pool 2‐Butoxyethanol 224 22.5 (0.0021 ppm)

Well Test Deck Carbon Monoxide 744 N/A Range: 0–5 ppm; Avg: 0 ppm

Well Test Deck Dipropylene glycol

butyl ether

751 74.9 <0.0009 ppm

Moon Pool Dipropylene glycol

butyl ether

224 22.5 <0.003 ppm

Well Test Deck Dipropylene glycol

methyl ether

751 74.9 <0.0004 ppm

Moon Pool Dipropylene glycol

methyl ether

224 22.5 <0.001 ppm

Well Test Deck Ethyl benzene 751 75.6 <0.0006 ppm

Moon Pool Ethyl benzene 224 22.5 <0.002 ppm

Well Test Deck Limonene 751 75.6 (0.0011 ppm)

Moon Pool Limonene 224 22.5 <0.002 ppm

Well Test Deck Naphthalene 751 75.6 <0.0005 ppm

Moon Pool Naphthalene 224 22.5 <0.002 ppm

Well Test Deck Toluene 751 75.6 <0.0007 ppm

Moon Pool Toluene 224 22.5 <0.002 ppm

Well Test Deck Total hydrocarbons 751 75.6 0.13 mg/m3

Moon Pool Total hydrocarbons 224 22.5 0.080 mg/m3

Well Test Deck Xylenes 751 75.6 <0.001 ppm

Moon Pool Xylenes 224 22.5 <0.004 ppm

*N/A = not applicable

†Concentrations reported as “<” were not detected; the given value is the minimum detectable concentration

‡Concentrations in parentheses were between the minimum detectable concentration and the minimum quantifiable

concentration (parentheses are used to point out there is more uncertainty associated with these values than values above the

minimum quantifiable concentration)
4C‐30  

Table 5. Health symptom survey—demographics by vessel

Development Driller II* Discoverer

Enterprise†

Unexposed‡

Number of participants 28 34 103

Age range 22–60 21–55 18–70

Race

     White 71% 82% 40%

     Hispanic 4% 0% 29%

     Asian 0% 0% 9%

     Black 21% 12% 19%

     Other/Missing 4% 6% 3%

Male 96% 97% 96%

Days worked oil spill 13–70 7–65 0–45

Days worked boat 0–60 6–50 0

* Surveys were collected aboard the Development Driller II on June 21–22, 2010.

†Surveys were collected aboard the Discoverer Enterprise on June 22–23, 2010.

‡Participants were recruited from the Venice Field Operations Branch and the Venice Commanders’ Camp. Those who reported

that they had not worked on boats and had no exposures to oil, dispersant, cleaner, or other chemicals were included in this

group.  

   
4C‐31  

Table 6. Health symptom survey—reported injuries and symptoms by vessel

   Development

Driller II*

Discoverer

Enterprise† Unexposed‡

Number of participants 28 34‡ 103

Injuries 

Scrapes or cuts 1 1 11 (11%)

Burns by fire 0 0 1 (1%)

Chemical burns 0 0 0

Bad Sunburn 0 0 8 (8%)

Constitutional symptoms  

Headaches 7 12 5 (5%)

Feeling faint, dizziness, fatigue or exhaustion, or weakness 4 2 13 (13%)

Eye and upper respiratory symptoms 

Itchy eyes 5 5 5 (5%)

Nose irritation, sinus problems, or sore throat 5 7 16 (16%)

Metallic taste 0 0 0

Lower respiratory symptoms 

Coughing 4 1 8 (8%)

Trouble breathing, short of breath, chest tightness, wheezing 3 1 4 (4%)

Cardiovascular symptoms 

Fast heart beat 0 0 1 (1%)

Chest pressure 1 0 0

Gastrointestinal symptoms 

Nausea or vomiting 2 3 3 (3%)

Stomach cramps or diarrhea 5 0 7 (7%)

Skin symptoms 

Itchy skin, red skin, or rash 6 1 8 (8%)

Musculoskeletal symptoms 

Hand, shoulder, or back pain 3 0 6 (6%)

Psychosocial symptoms 

Feeling worried or stressed 9 2 4 (4%)

Feeling pressured 4 1 2 (2%)

Feeling depressed or hopeless 0 0 1 (1%)

Feeling short tempered 2 0 4 (4%)

Frequent changes in mood 3 0 3 (3%)

Heat stress symptoms §

Any 8 13 21 (20%)

4 or more symptoms 2 1 3 (3%)

*Surveys were collected aboard the Development Driller II on June 21–22, 2010.

†Surveys were collected aboard the Discoverer Enterprise on June 22–23, 2010.

‡Participants were recruited from the Venice Field Operations Branch and the Venice Commanders’ Camp. Those who reported

that they had not worked on boats and had no exposures to oil, dispersant, cleaner, or other chemicals were included in this

group.  

§Headache, dizziness, feeling faint, fatigue or exhaustion, weakness, fast heart beat, nausea, red skin, or hot and dry skin.