ASSESSMENT OF FIRE FIGHTER EXPOSURE TO HALOTRON (HCFC-123) 

DURING EXTINGUISHANT EFFICIENCY TESTING 

CONDUCTED AT THE UNITED STATES NAVAL AIR STATION 

IN BEAUFORT, SOUTH CAROLINA 

Submitted to: 

Global Change Division 

Office of Air and Radiation 

Environmental Protection Agency 

EPA Contract No. 68-D90068 

Work Assignment No. 4-44 

and 

American Pacific Corporation 

3770 Howard Hughes Parkway 

Las Vegas, Nevada 89101 

May 24, 1993 
ASSESS:MENT OF FIREF1GHTER EXPOSURE TO HCFC-123 

DURING EXTINGUISHANT EFFICffiNCY TESTS 

CONDUCTED AT TFfF. UNITED STATES NAVAL AIR STATION 

IN BEAUFORT, SOUTH CAROLINA 

Submitted to: 

Global Change Division 

Office of Air and Radiation 

Environmental Protection Agency 

EPA Contract No. 68-090068 

Work Assignment No. 4-44 

and 

American Pacific Corporation 

3770 Howard Hughes Parkway 

Las Vegas, Nevada 89101 

submitted by:-

Meridian Research, Inc. 

1010 Wayne Avenue, Suite 1220 

Silver Spring, MD 20910 

May 24, 1993 
ASSESSMENT OF FIREFIGHTER EXPOSURE TO HCFC-123 

DURING EXTINGUISHANT EFFICIENCY TESTS 

CONDUCTED AT THE UNITED STATES NAY AL AIR STATION 

IN BEAUFORT, SOUTH CAROLINA 

I. PURPOSE 

Under Title IV, Section 612 of the Clean Air Act Amendments (CAAA) of 1990, 

the Environmental Protection Agency (EPA) is required to develop regulations 

governing the use of substitute materials for ozone-depleting chlorofluorocarbons 

(CFC's) and halons. The statute requires the replacement, to the maximum extent 

practicable, of these materials with alternatives that reduce the overall risks to humans 

and the environment. In order to make these determinations, EPA must evaluate the 

risks potentially associated with exposures of consumers, workers, and the general 

population to alternative compounds. 

One such alternative to the use of halon fire extinguishing agent is Halotron I, 

which contains HCFC-123 (2,2-dichloro-1,1,1-trifluoroethane) as the primary active 

ingredient. Recently, concerns regarding the potential toxicity of HCFC-123 and 

associated risks to exposed workers have arisen from the results of animal toxicity 

testing; in response to these findings, the EJ. duPont deNemours Co., the sole U.S. 

manufacturer of HCFC-123, recommended that exposures to HCFC-123 not exceed 

10 parts per million (ppm) parts of air as an 8-hour time-weighted average (TWA), 1,000 

ppm for 30-minute exposures, or 2,500 ppm for 1-minute exposures. 

On October 21 and 22, 1992, Meridian Research, Inc. conducted an exposure 

assessment survey to determine the extent of frrefighter exposure to HCFC-123 during 

the use of Halotron I fire extinguishing agent. The survey was sponsored jointly by the 

Environmental Protection Agency (EPA) and American Pacillc Corporation, which 

manufactures Halotron I. The exposure assessment survey was performed during actual 

fuefighting exercises being conducted to examine the effectiveness of Halotron I. 

1 
II. FACILTIY AND FIRE SCENARIO DESCRIPTION 

The extinguishant effectiveness testing was conducted in a specially designed flre 

figb.ting test area at the Beaufort Naval Air Station. The fire pit consisted of a circular 

area about 40 feet in diameter surrounded by a 12-inch high asphalt berm. The pit was 

sectioned by a small concrete curb to form a smaller internal pit of approximately 

800 square feet in area, and was equipped with an automatic fuel charging system and a 

drain for removing water, fuel, and extinguishant. All of the tests were conducted within 

this outdoor flre pit by members of the air station's Crash, Fire, and Rescue Division. 

JP-5 jet fuel was used in all of the fire tests, and both halon and Halotron I 

extinguishing agents were tested. The testing program consisted of four separate trials 

for each of four different flre scenarios, for a total of 16 trial events, that were designed 

to represent actual flight line fue situations encountered by rescue personnel. Wherever 

possible, steps were taken to ensure consistency between trials for each fue scenario. 

The amount of fuel used for each trial was kept constant by draining the fuel-holding 

containers after each event, and approximately the same pre-burn time was used for each 

trial. 

The first flre scenario tested was the pan (or small pit) fire, in which a 6-foot by 

12-foot by 8-inch-deep metal container was filled with water; 10 gallons of JP-5 were 

introduced and allowed to float in a thin layer on the water. During the four Halotron I 

events, the wind speed ranged from 05 to 1 mile per hour (mph), with occasional light 

gusts to 3 mph, as measured by a SPER Scientific anemometer. The firefighter situated 

himself upwind of the fire and used a 20-pound hand-held Halotron I extinguisher to 

fight the flre. The extinguishant discharge times for these events were between 4 and 5 

seconds and at no time during the event was the firefighter required to move into the 

smoke cloud generated during the test. 

The second flre test scenario was a simulated dual-engine frre, which utilized 

5 gallons of JP-5 fuel in each of 2 engine nacelle mock-ups. The mock-ups were placed 

roughly 6 feet off the ground on metal support frames. This type of frre was also fought 

with a 20-pound hand-held extinguisher, and the firefighter began from an upwind 

2 
position. Although the discharge times for this test were extremely brief, between 2 and 

3 seconds, the firefighter was required to walk around the mock-ups to check the back 

side of the nacelles to ensure that the fire was completely extinguished; in two of the 

four trials, this required the firefighter to stand for a few seconds in the visible cloud of 

smoke generated during the test. 

The third fire scenario was a running fuel fire, in which a single engine nacelle 

mock-up on a metal support frame was placed in a 6-foot by 12-foot pan. Five gallons of 

JP-5 fuel were placed in each the engine mock-up and in the pan. Fuel was allowed to 

trickle from the engine mock-up to the pan below, and both the engine and pan were 

ignited. The firefighter remained upwind during these tests, and fought the fire with a 

20-pound hand-held unit by extinguishing the pan fire first and then extinguishing the fire 

in the engine mock-up. The discharge times for these events were between 6.8 and 

16.6 seconds, and the wind was gusting slightly at about 4 mph. 

The large pit fire was the fmal type of fire test performed during these exercises. 

This test used 100 gallons of JP-5 floated on a layer of water contained in an 800 squarefoot area of the fire test pit. Prior to ignition, the fuel for this test was spread evenly on 

the water by dragging a spreader-board across the surface. For these trial events, the 

firefighter used a semi-portable 150-pound Halotron I extinguisher, which remained on a 

wheeled cart and was equipped with a long hose and nozzle assembly that allowed the 

firefighter sufficient mobility to move around a large area. The firefighter attacked the 

fires from an upwind direction. Wind speed during these tests ranged from no 

appreciable wind speed to approximately 8 mph. The discharge time for these tests 

ranged from 11 to 37 seconds. During the second trial, the firefighter did not succeed in 

extinguishing the fire and was observed to have stood for a few seconds in the visible 

smoke cloud before withdrawing from the area. 

During all of the fire tests performed for this survey, the firefighter wore a full 

complement of protective clothing that included self-contained breathing apparatus 

(SCBA). However, the exposure results obtained from this survey are representative of 

exposures that would likely occur during similar fire events if the firefighter was not 

wearing SCBA. 

3 
ill. SAMPLING METHODS AND ANALYSIS 

This exposure survey involved collecting personal breathing zone air samples 

representing the exposure of the frrefighter during each of sixteen frre events. Air 

samples were taken using a 1-liter Tedlar bag attached to an SKC Model 224 personal 

sampling pump. In addition, air sampling for the pyrolysis products of HCFC-123 

(including hydrogen fluoride and hydrogen chloride) was performed using Draeger 

colorimetric detector tubes. 

The 1-liter Tedlar bags used to collect air samples during all events were attached 

to the back of the firefighter's protective hood piece. A standard sampling cassette 

holder equipped with a half cassette was attached near the firefighter's breathing zone. 

Tygon tubing was used to connect the cassette holder to the sampling pump air inlet and 

from the exhaust port of the pump to the Tedlar bag. The flow rate of the pump was set 

between 0.75 liter per minute and 1.75 liters per minute, depending on the expected 

duration of Halotron I discharge. 

On 11 of the 16 trials, the firefighter was equipped with both a Tedlar bag and a 

Draeger colorimetric detector tube specific for either hydrogen fluoride (HF) or 

hydrogen chloride (HCl). An SKC Model 224 personal sampling pump was used to draw 

air through the Draeger tube at flow rates specified by the manufacturer. The flow rates 

for the. Draeger tubes were 650 eel minute and 800 eel minute for the HCl and HF tubes, 

respectively. Results from the Draeger colorimetric detector tubes were obtained 

immediately after each trial. 

The 1-liter Tedlar bag samples were analyzed using gas chromatography (GC) by 

a laboratory accredited by the American Industrial Hygiene Association (Gascoyne 

Laboratories, Inc., Baltimore, Maryland). The column used by Gascoyne was 5 percent 

Krytrox 143 AC on Graphpac GB with a 60/80 mesh that was 10 feet by 118 inch SS and 

had a flow of 30 ml/ minute (helium). The following GC conditions were noted: 

injection temperature 22SOC; detector temperature 25<J>C; a run time of 16 minutes; and 

an oven temperature of 7<? C (isothermal). A Perkins-Elmer gas chromatograph with a 

sigma 1B analyzer equipped with a flame ionization detector (FID) and a sigma 1B 

integrator/ GC control was used for analysis. Injections were done with a gas-tight 

4 
syringe. Ten percent of the samples were analyzed in duplicate as a quality control 

procedure. 

To examine the stability of HCFC-123 in Tedlar bags, Gascoyne performed a 

decay rate study using 10, 100, and 1000 ppm concentrations of HCFC-123 spiked into 

Tedlar bags. The spiked samples were held at room temperature and alloquats were 

withdrawn for analysis at various intervals over a 3-day period. The results of this decay 

rate study are shown in Attachment 1, and demonstrate that there was no significant 

sample loss over the 3-day test period. 

IV. RESULTS AND DISCUSSION 

Table 1 shows the results of all exposure monitoring performed during this survey. 

Personal breathing zone samples of HCFC-123 taken during firefighting exercises did not 

exceed 1 ,000 ppm for any of the four fire scenarios. In addition, breathing zone 

measurements for HCl and HF were well below established IDLH (Immediately 

Dangerous to Life and Health) concentrations of 100 and 30 ppm, respectively. Two of 

the four samples taken for HF met the American Conference of Governmental Industrial 

Hygienists (ACGIH) Threshold Limit Value (TL V) of 3 ppm as a ceiling limit. 

However, it should be noted that carbonyl fluoride, a potential decomposition product of 

HCFC,.:I23, is likely to react positively with the HF Draeger tube; thus, actual 

concentrations of HF in the frrefighter's breathing zone may have been lower than that 

detected. None of the HCl samples met or exceeded the ACGIH 5 ppm TL V -Ceiling 

limit. Comparison of the exposure monitoring results with DuPont's allowable exposure 

limits for HCFC-123 and the ACGIH TLV's HF and HCI shows that, under the 

conditions of these tests, the Halotron I fire extinguishing agent is safe to use from the 

perspective of worker health. 

The highest concentrations of HCFC-123 and its pyrolysis products arose during 

the dual engine fire trials. Although the discharge time for this test fire was extremely 

brief (3 seconds or less), the frrefighter was required to walk around the engine mock5 
Table 1. Results of HCFC~123 Exposure Monitoring Conducted During 

Outdoor Fireflghting Exercises 

Discharge HCFC-123 

Duration Concentration Results From 

Sample No. Type of Test Trial No. (seconds) (ppm) Draeger Tubes 

1 Pan Fire 1 4 100 

2 Pan Fire 2 4 31 HCl Tube/ND 

3 Pan Fire 3 4 ND HF Tube/ND 

4 Pan Fire 4 5 23 

5 Dual Engine Fire 1 3 100 

6 Dual Engine Fire 2 2 720 HF Tube/ 3 ppm 

7 Dual Engine Fire 3 2 94 HCl Tube/ND 

8 Dual Engine Fire 4 2 870 HCI Tube/15 ppm 

9 Running Fuel Fire 1 11.6 24 HC1 Tube/ND 

10 Running Fuel Fire 2 16.6 24 HF Tube/ND 

11 Running Fuel Fire 3 10.6 7.1 

12 Running Fuel Fire 4 6.8 15 

13 Pit Fire 1 33 12 HCI Tube/ND 

14 Pit Fire 2 37 17 HF Tube/ 3 ppm 

15 Pit Fire 3 11 + HCl Tube/ND 

16 Pit Fire 4 13.9 85 HCI Tube/ND 

ND Not Detected. 

+ Detected below quantitation limit. 

6 
ups to ensure that the flre was completely extinguished. This meant that the flreflghter 

had to move to the downwind side of the flre. On two of the four trials (trial numbers 2 

and 4. sample numbers 6 and 8). the frreflghter was observed to be standing in the 

smoke cloud while he checked the engines. These two trials resulted in the highest 

concentrations both of HCFC-123 and its pyrolysis products. Trial 2 resulted in an 

HCFC-123 exposure of 720 ppm and a hydrogen fluoride exposure of 3 ppm, and Trial 4 

resulted in an HCFC-123 exposure of 870 ppm and a hydrogen chloride exposure of 15 

ppm. The lowest HCFC-123 sample reported during this type of test was 94 ppm (Trial 

3). 

The pit frre, which was fueled by 100 gallons of the JP-5 jet fuel, required the 

longest discharge times of any of the fire scenarios; however, the resulting exposures to 

HCFC-123 were generally less than for any of the other three fire scenarios. This 

suggests that the position of the frreflghter relative to the direction of agent discharge 

and the wind are more important factors influencing the magnitude of exposure than is 

the amount of agent discharged. 

7 
ATTACHMENT I 

~et£1.CU1Jtt2 'lfiahnra±nries, ~n.c~ . Baltimore, MD 21224 

~m~~w~ 

(410)633-1800 

FAX NO. 

(410) 633-6553 

(800) GAS-COYN 

Report No. 92-10-487 Report Date! November 19, 1992 

Report To: Meridian Research Page! 2 of 4 

Elansed 

0 hours 

8 hours 

24 hours 

32 hours 

48 hours 

72 hours 

Notes: 

Time 

Decay Rate Study of Laboratory Prepared HCFC-123 in Air Samples 

Theoretical 

Value = 8.9 ppm 

7.7, 7.7 

7.5, 7.5 

.8 • 0 t 8.2 

8.6, 9.5 

8.4, 8.2 

8.7, 8.0 

Theoretical 

Value = 89 ppm 

76, 82 

80, 78 

79, 100 

120, 91 

84, 91 

100, 125 

Theoretical 

Value = 890 pcm 

1100, 1100 

940, 950 

1000, 1000 

1000, 1000 

1000, 1000 

900, 920 

(1) Results are expressed in parts per million (ppm). 

(2) Duplicate analyses are reported for each time period. 

(3) Analysis performed w-ith parameters outlined in method submitted 

to Gascoyne Laboratories, Inc.· by Meridian Research-

( 4) All analyses were performed ± 1 hour of target analysis time. 

(5) Analyst(s): JMRfSJN; Date Test Completed: 11/06/92 

~-

William L. Lock 

Laboratory Director