|<< Back to Sampling and Analytical Methods
For problems with accessibility in using figures and illustrations in this method, please contact the SLTC at (801) 233-4900.
These procedures were designed and tested for internal use by OSHA personnel. Mention of any company name or commercial product does not constitute endorsement by OSHA.
Vinyl Bromide - (Organic Method #008)
Related Information: Chemical Sampling - Vinyl Bromide
||Collection on charcoal, desorption with carbon
disulfide, analysis by GC with a flame ionization detector.
Samples should be stored in a refrigerator and analyzed as soon
|Detection limit based
on recommended air volume:
|Recommended air volume
and sampling rate:
|5.0 L at 0.2 L/min
|Standard error of estimate
at the target concentration:
|Status of method:
||Evaluated method. This method has been subjected to
the established evaluation procedures of the Organic Methods
|Date: May 1979
||Chemist: Dee R. Chambers
Organic Methods Evaluation Branch
1. General Discussion
OSHA Analytical Laboratory
Salt Lake City, Utah
2. Sampling Procedure
1.2. Detection limit, precision, sensitivity, and working range
In September 1978, NIOSH and OSHA issued "Current Intelligent
Bulletin Number 28", which recommended that vinyl
bromide be considered as a potential human carcinogen in
the workplace. In addition, they indicated that safe
levels of exposure to carcinogens have not been demonstrated,
but lowered exposure to carcinogens may, in general,
decrease the probability of cancer development.
There is not an exposure standard for vinyl bromide at the
present time. A target level of 1 ppm was selected because
of limitations of analytical detection and because 1
ppm is the PEL for vinyl chloride (Ref. 5.1.).
1.1.2. Toxic effects
Laboratory studies have demonstrated that exposure to
vinyl bromide caused angiosarcoma of the liver and other
cancers in animals. At levels of 10 ppm, exposure induced
lymph node angiosarcoma. Additionally, adverse health
effects in animals attributed to vinyl bromide include
central nervous system effects, cardiovascular effects,
respiratory effects, skin effects, skeletal effects, and
liver and spleen abnormalities. (Ref. 5.1.)
To date, there have been no reported cases of cancer in
humans associated with exposure to vinyl bromide; however,
vinyl bromide has been in commercial production in the
United States only since 1971.
Industries which use vinyl bromide include: chemical and
allied products, rubber and plastic products, leather
products, fabricated metal products, and wholesale trade.
1.1.4. Approximately 360 workers are exposed to vinyl bromide and
an additional 26,000 workers are potentially exposed
1.1.5. Physical properties
CH2CHBr molecular weight 107
Vinyl bromide is a gas which is flammable and poses a
dangerous fire risk. Its melting point is -138°C and its
boiling point is 15.6°C. The specific gravity of vinyl
bromide is 1.51. (Ref. 5.2.)
1.2.1. The detection limit for the analytical procedure is 4 ng
per injection. This is based on 1-µL injections.
1.2.2. The pooled coefficient of variation of the analytical
method over the range equivalent to 1.0 ppm to 10 ppm
based on the recommended air volume is 1.1%. (Section
1.2.3. The sensitivity of the analytical procedure at 1 ppm based
on a 5-L air volume is 250 area units per µg/mL. The
sensitivity is determined by the slope of the calibration
curve. The sensitivity will vary with the particular
instrument used in the analysis. (Section 4.2.)
1.2.4. The lower limit of the estimated working range is 0.2 ppm.
The upper limit is dependent on the capacity of the charcoal.
1.3.1. The overall procedure must provide results that are within
25% of the true value or better at the 95% confidence
1.3.2. The recovery of analyte from the collection medium after
storage must be 75% or better.
1.3.3. The overall procedure meets the above criteria. (Section
The method of sampling is convenient. Charcoal tubes are easily
transported to the laboratory through the mail. The analytical
method is quick, and automation of the process is possible.
It may be difficult to analyze for additional components on the
same charcoal tube.
3. Analytical Procedure
2.1.1. An approved and calibrated personal sampling pump whose
flow can be determined within ±5% at 0.2 L/min.
2.1.2. Charcoal tubes: Glass tube, with both ends heat sealed,
7.0 cm × 6-mm o.d. × 4-mm i.d., containing 100-mg front
and 50-mg backup sections of 20/40 mesh coconut base charcoal.
SKC Lot 106 or equivalent are adequate.
2.3. Sampling technique
2.3.1. Immediately before sampling, break the ends of the
charcoal tubes. All tubes must be from the same lot.
2.3.2. Connect a charcoal tube to the sampling pump with flexible
tubing. The short section of the charcoal tube is used as
a backup section and should be positioned nearer the pump.
2.3.3. The tube should be placed in a vertical position during
sampling to minimize channeling.
2.3.4. Air being sampled should not pass through any hose or
tubing before entering the charcoal tubes.
2.3.5. Seal the charcoal tubes with plastic caps immediately
2.3.6. With each batch of samples, submit at least one blank tube
from the same lot used for samples. This tube should be
subjected to exactly the same handling as the samples
(break, seal, transport) except that no air is drawn
2.3.7. Transport the samples (and corresponding paperwork) to the
lab for analysis.
At the sampling rate of 0.2 L/min, an atmosphere at 80% relative
humidity containing 1 ppm vinyl bromide was sampled for 5 L with
no breakthrough from the primary portion of the charcoal tube. If
the concentration is thought to be extremely high in the
workplace, two charcoal tubes may be connected in series and/or the
sampling rate lowered, together with a smaller air volume sampled
to prevent breakthrough.
2.5. Desorption efficiency
2.5.1. The desorption efficiency may vary from laboratory to
laboratory and for each lot of charcoal.
2.6. Recommended air volume and sampling rate
2.5.2. The desorption efficiency at 8.8 µg loadings (0.4 ppm at
recommended air volume) was 100%. The desorption
efficiency at 17.5 µg loadings (0.8 ppm at recommended air
volume) was 100%, and the desorption efficiency at 35 µg
loadings (1.6 ppm at recommended air volume) was 95%.
2.6.1. The recommended air volume is 5 L.
2.7. Interferences (sampling)
2.6.2. The recommended sampling rate is 0.2 L/min.
2.7.1. At the present time, it is unknown if any compound would
severely interfere with the collection of vinyl bromide on
charcoal. In general, the presence of other solvents will
decrease the breakthrough volume for a particular solvent.
2.8. Safety precautions
2.7.2. Any compound which is suspected of interfering in the
collection or analysis should be listed on the sampling
2.8.1. Safety glasses should be worn when breaking the ends of
2.8.2. Do not provide any spark source from pumps or other
equipment when working in environments containing flammable
2.8.3. Observe all usual safety practices when sampling in
4. Backup Data
3.1.1. Gas chromatograph equipped with a flame ionization detector.
3.1.2. Stainless steel column (20 ft × 0.125 in.) packed with 10%
SE-30 on 80/100 mesh Chromosorb W (acid washed, silanized
with dimethyl dichlorosilane). Other columns capable of
performing the required separation may be used.
3.1.3. An electronic or mechanical integrator or some other
method of determining peak area.
3.1.4. Vials (2-mL) that can be sealed with caps containing
3.1.5. Microliter syringe, 1-µL for injecting samples.
3.1.6. One-milliliter gas-tight syringe for preparing standards.
3.1.7. Volumetric flasks, convenient sizes for preparing standards.
3.2.1. Carbon disulfide, spectroquality or better.
3.3. Standard preparation
3.2.2. Vinyl bromide, pure or known concentration.
3.2.3. n-Heptane, spectroquality or better.
3.2.4. Purified helium carrier gas.
3.2.5. Purified hydrogen and air.
3.2.6. Desorbing reagent contains 0.1 mL n-heptane per liter of
Standards are prepared by injecting with a gas-tight syringe an
amount of vinyl bromide into a volumetric flask containing
desorbing reagent. The parts-per-million value in air that this
standard represents depends on the concentration of vinyl bromide
used, the amount injected, and the size of volumetric flask.
Standards should be near 1 ppm for a 5-L air volume.
3.4. Sample preparation
3.4.1. The front and back sections of each sample are transferred
to separate vials.
3.4.2. Each section is desorbed with 1.0 mL desorbing reagent.
3.4.3. The vials are sealed immediately and allowed to desorb for
30 min with intermediate shaking.
3.5.1. GC conditions
3.6. Interferences (analytical)
|flow rates (mL/min)
||1.5 min (vinyl bromide)
3.5.2. Peak areas are measured by an electronic integrator or
other suitable means.
3.5.3. An internal standard procedure is used. The integrator is
calibrated to report results in ppm for a 1-L air volume.
3.5.4. The amount must be corrected for the desorption efficiency.
3.6.1. Any compound having the same general retention time of
vinyl bromide or n-heptane is an interference. GC parameters
should be chosen to circumvent these interferences.
3.6.2. Retention time data on a single column is not considered
proof of chemical identity. Samples over the PEL should
be confirmed by GC/MS or other suitable means.
3.7.1. Since the integrator is programmed to report results in
ppm (at 25°C and 760 mm Hg, and corrected for desorption
efficiency) for a 1-L air volume, the following calculation
3.8. Safety precautions
ppm vinyl bromide = A/B
||ppm on report
3.7.2. Add both charcoal tubes (if they were in series) before
reporting the results.
3.8.1. All work done with the solvents and with the vinyl bromide
gas should be done in a hood.
3.8.2. Avoid any skin contact with all the solvents.
3.8.3. Vinyl bromide should be considered a human carcinogen, and
all work with vinyl bromide should be done using appropriate
4.1. Coefficient of variation of analytical technique
The coefficient of variation was determined from multiple injections
of analytical standards which covered a concentration range
equivalent to 1.0 ppm to 10 ppm, based on a 5-L sample.
| = 0.011
The sensitivity is determined from the slope of the calibration
curve shown in Figure 4.2.
(5489 area counts)/(22 µg/mL) = 250 area counts/µg/mL
4.3. Desorption efficiency
Three groups of six, Lot 106, charcoal tubes were respectively
spiked with 5, 10, and 20 µL of a 400 µL vinyl bromide/mL CS2
solution. The backup portion of the tubes had been removed prior
to spiking. The tubes were allowed to equilibrate.
4.4. Storage test
The percent recoveries are not corrected for desorption efficiency.
Samples were collected at 80% relative humidity. The loadings
were approximately 10 µg/sample. One group of samples were
stored at ambient temperature and a second group at reduced
temperature. Three samples from each group were analyzed at
intervals throughout a 16-day period. These data are presented
graphically in Figures 4.4.1. and 4.4.2.
Figure 4.2. Calibration curve of instrument response to vinyl bromide.
Figure 4.4.1. Ambient storage test of vinyl bromide.
Figure 4.4.2. Refrigerated storage test of vinyl bromide.
5.1. "Current Intelligence Bulletin 28" NIOSH, 1978.
5.2. "The Condensed Chemical Dictionary", 8th Edition, 1971.