Document ID: EPA-HQ-OAR-2002-0064-0211
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2007-03-28T04:00Z

To:  T. J.  Herman							             March 9, 2004

From:  S. A. Hawk					         		              	   

Subject:     Industrial Hygiene Air Sampling Report For Normal propyl
bromide (nPB) Based Mouth Waterproofing in Manufacture of 5.56 mm
Ammunition.      

 

Executive Summary  

Current environmental requirements necessitate the elimination of 1,1,1
Trichloroethane  (TCA), an ozone depleting substance (ODS), in the
production of ammunition manufactured for the Federal Government.   TCA
is the solvent in the current asphalt based mouth-waterproofing compound
for production of 5.56 mm cartridges.

Attempts over the past several years have been made to find an
“environmentally friendly” substitute for TCA.  Each of the possible
replacement solvents shared a fundamental problem; they were not
compatible with the 5.56 mm high speed manufacturing equipment.  A new
team of engineers was assembled in 2002 to investigate substitute
solvents.  Through an extensive evaluation the team identified a
suitable substitute, nPB. 

An nPB based mouth-waterproofing compound was developed that matched the
entire chemical and physical characteristics of the TCA compound.   

Air Sampling Results

Industrial Hygiene air samples were collected on different days and
shifts while the nPB mouth waterproofing was used.  Survey Samples were
collected by placing SKC passive samplers (575-002A) in the breathing
zone of exposed workers. Samples were collected for a full shift for
which time weighted average were reported.  Samples were analyzed by
ENTEK Environmental Laboratories, an American Industrial Hygiene
Association accredited laboratory, using NIOSH method 1003.

No results were above the manufacturer’s recommended exposure of 25
ppm. With exception of one result, sample number 11-24-7 with 21.47 ppm,
all readings were below half of the 25-ppm recommendation.  This
21.47-ppm result is difficult to explain when compared to the 3.41-ppm
result of sample number 11-24-8.  Both results originated from doing the
same job on the same machine.

Tabled results are as follows:

Results of nPB Air Sampling Building 2 Priming Wing 

Date Sampled	Sample 	Line	Shift	Job Title	 Limit	TWA (ppm)

11/03/2003	11-3-1	1	D	Tool Setter	25 ppm	1.23

11/03/2003	11-3-2	3	D	Tool Setter	25 ppm	2.71

11/03/2003	11-3-3	2	D	Tool Setter	25 ppm	1.17

11/04/2003	11-4-1	3	D	Tool Setter	25 ppm	2.80

11/04/2003	11-4-2	2	D	Operator	25 ppm	1.65

11/04/2003	11-4-3	1	D	Tool Setter	25 ppm	3.04

11/06/2003	11-6-1	1	D	Tool Setter	25 ppm	3.68

11/06/2003	11-6-2	3	D	Tool Setter	25 ppm	4.00

11/06/2003	11-6-3	2	D	Operator	25 ppm	2.74

 	 	 	 	 	Average	2.56

 

Results of nPB Air Sampling Building 1 Priming Wing - Blank Line Only

Date Sampled	Sample 	Line	Shift	Job Title	 Limit	TWA (ppm)

10/202003	20-1	5	D	Op Tech	25 ppm	1.32

10/20/2003	20-2	5	D	Op Tech	25 ppm	1.83

10/22/2003	22-1	5	D	Op Tech	25 ppm	0.58

10/22/2003	22-2	5	D	Op Tech	25 ppm	1.63

10/27/2003	27-1	5	D	Op Tech	25 ppm	1.44

10/27/2003	27-2	5	D	Op Tech	25 ppm	2.69

 	 	 	 	 	Average	1.58

Results of nPB Air Sampling Building 1 Priming Wing - Evening Shift,
Four Lines Running.

Date Sampled	Sample 	Line	Shift	Job Title	 Limit	TWA (ppm)

11/21/2003	11-21-3	3	E	Op Tech	25 ppm	4.32

11/21/2003	11-21-4	2	E	Op Tech	25 ppm	5.69

11/21/2003	11-21-5	4	E	Op Tech	25 ppm	4.02

11/21/2003	11-21-6	5	E	Op Tech	25 ppm	2.98

11/21/2003	11-21-7	Mat. Handler	E	Mat. Handler	25 ppm	0.86

11/24/2003	11-24-1	4	E	Op Tech	25 ppm	9.16

11/24/2003	11-24-2	Mat. Handler	E	Op Tech	25 ppm	4.75

11/24/2003	11-24-3	3	E	Op Tech	25 ppm	6.1

11/24/2003	11-24-4	4	E	Op Tech	25 ppm	6.45

11/24/2003	11-24-5	2	E	Op Tech	25 ppm	8.05

11/24/2003	11-24-6	Mat. Handler	E	Mat. Handler	25 ppm	0.93

11/24/2003	11-24-7	5	E	Op Tech	25 ppm	21.47

11/24/2003	11-24-8	5	E	Op Tech	25 ppm	3.41

 	 	 	 	 	Average	6.01

Results of nPB Air Sampling Building 1 Priming Wing - Area Samples of
Mez Storage 

Date Sampled	Sample 	Line	Shift	Job Title	 Limit	TWA (ppm)

11/20/2003	11-20-6	Mez Storage	D	NA	NA	0.98

11/21/2003	11-21-2	Mez Storage	D	NA	NA	1.88

11/24/2003	11-24-9	Mez Storage	E	NA	NA	1.84

 	 	 	 	 	Average	1.57

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