EPA-600/2-76-124
May 1976
Environmental Protection Technology Series
           SAMPLING  OF AUTOMOBILE  INTERIORS  FOR
                               VINYL CHLORIDE MONOMER
                                    Industrial Environmental Research Laboratory
                                          Office of Research and Development
                                         U.S. Environmental Protection Agency
                                   Research Triangle Park, North Carolina 27711

-------
               RESEARCH REPORTING SERIES

Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into five series. These five broad
categories were established to facilitate further development and application of
environmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The five series are:

     1.   Environmental Health Effects Research
     2.   Environmental Protection Technology
     3!   Ecological Research
     4.   Environmental Monitoring
     5.   Socioeconomic  Environmental Studies

This report has been assigned  to the ENVIRONMENTAL PROTECTION
TECHNOLOGY series. This series describes research performed to develop and
demonstrate instrumentation, equipment, and methodology to repair or prevent
environmental degradation  from point and non-point sources of pollution. This
work provides the new or  improved technology required for the control and
treatment of pollution sources to meet environmental quality standards.
                    EPA REVIEW NOTICE

This report has been reviewed by  the U.S.  Environmental
Protection Agency, and approved for publication.  Approval
does not signify that the contents necessarily reflect the
views and policy of the Agency, nor does mention of trade
names or commercial products constitute endorsement or
recommendation for use.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.

-------
                                  EPA-600/2-76-124

                                  May 1976
               SAMPLING

    OF AUTOMOBILE INTERIORS

  FOR  VINYL CHLORIDE MONOMER
                     by
    William H. Hedley, Joseph T.  Cheng
 Robert J. McCormick, and Woodrow A.  Lewis

        Monsanto Research Corporation
             1515 Nicholas Road
             Dayton, Ohio 45407
  Contract No. 68-02-1404, Task 1 (Change 2)
            ROAPNo. 21AXM-073
        Program Element No. 1AB015
   EPA Project Officer:  David K. Oestreich

 Industrial Environmental Research Laboratory
   Office of Energy, Minerals, and Industry
      Research Triangle Park, NC 27711
                Prepared for

U.S. ENVIRONMENTAL PROTECTION AGENCY
      Office of Research and Development
            Washington, DC  20460

-------
                            ABSTRACT

The report gives results of a study to qualitatively identify or-
ganic pollutants in the air inside new automobiles.  In recent
years, concern has developed over the concentration of organic
vapors inside new automobiles.   A literature search first identi-
fied numerous volatilization products from plastics used in the
construction of automobile interiors.  Charcoal tubes were used
to collect air samples in seven test vehicles.  The concentrations
in the other five test vehicles during this preliminary study were
below the detection limit of 0.05 ppm.
                                11

-------
Abstract
Figures
Tables
                            CONTENTS
Page
 ii
 iv
 iv
     I    Introduction
     II   Summary and Conclusions
     III  Literature Survey
          A.   Volatilization products of plastics
          B.   Suspected carcinogenic compounds
     IV   Sampling Procedures
          A.   Automobiles Sctmpled
          B.   Sample collection
     V    Sample Analysis
     VI   Results and Discussion
  1
  2
  3
  3
 11
 12
 12
 12
 15
 17
References
Appendices
 20
     A.   Data sheets                                        22
     B.   Sampling and analysis of vinyl chloride in air     26
                                111

-------
Number
                            FIGURES
          Charcoal tube used to collect VCM sample
Page
 13
                            TABLES
Number                                                      Page
  1       Summary of Uses of Plastics in Automobile
            Interiors                                         4
  2       ABS Volatilization Products                         5
  3       Volatilization Products of Plex 55 Acrylic          5
  4       Volatilization Products from Epoxy Adhesives        6
  5       Volatilization Products from Two Melamine Samples   7
  6       Volatilization Products of Phenolic Compounds       7
  7       Volatilization Products from Two Polyester/Glass    8
            Reinforced Samples
  8       Volatilization Products from Polypropylene 65-23    8
  9       Volatilization Products from Polyurethanes          9
 10       Volatilization Products from PVC                   10
 11       Volatilization Products from Plastics Used in
            the Interior of 1975 Automobiles                 11
 12       VCM in the Interior of 1975 Automobiles            18
                               IV

-------
                            SECTION I

                          INTRODUCTION

In recent years, some concern has developed over the concentra-
tions of organic vapors in the interior of new automobiles.  The
principal sources of these organic pollutants are the plastics,
rubbers, and adhesives that are extensively used in the interior
of automobiles.  The major volatilization products are unreacted
monomers, plasticizers, and solvents trapped in the polymer
during manufacture.  The concentration of these compounds which
are volatilized could exceed OSHA limits.

The purpose of this study was to obtain preliminary measurements
of the concentration of vinyl chloride monomer (VCM) in the air
in the interior of new automobiles.  A literature search was also
conducted to determine the expected volatilization products from
plastics used in the construction of new automobile interiors.

-------
                           SECTION  II

                     SUMMARY AND CONCLUSIONS

Preliminary measurements were made  of the vinyl chloride monomer
 (VCM) concentration in the interiors of seven different new 1975
automobiles.  These were:  Ford Pinto, Dodge Dart Sport, American
Motors Gremlin, Volkswagen Rabbit,  General Motors Vega, General
Motors Chevrolet, and a Datsun 710.  These compact and subcompact
cars were selected because their ratio of plastic to interior
volume was high and would be expected to result in worst-case con-
centrations' for VCM.

Charcoal tubes were used to collect samples for VCM analysis.
After drawing a known volume of air through each tube, the tubes
were transported back to the laboratory for analysis by the NIOSH
carbon disulfide extraction/gas chromatographic detection method.

Of the seven cars tested, only two, the Ford Pinto and the Dodge
Dart, had measurable amounts of VCM in the interior atmospheres.
These concentrations ranged from 0.4 ppm to 1.2 ppm.  In the
other five cars, the VCM concentrations were below the detection
limit of the analytical system, 0.05 ppm.

These data indicate that concentrations of vinyl chloride monomer
inside new cars rarely exceed the recommended exposure limit of
one ppm, even in cases where the cars have received little or no
ventilation.  Calculation of the maximum one-time exposure to VCM
in 1975 cars would not be expected to exceed 30 ppm, even assuming
zero loss of VCM from the polyvinylchloride from its time of manu-
facture until the time when it was all released inside the un-
ventilated car.

Volatilization of organic compounds from plastics used to construct
automobile interiors was studied.  A literature search was also
conducted to determine the potential volatilization products from
nineteen plastic and adhesive products typically used in automo-
bile interiors.  A total of 41 organic gases which volatilize
from these products at temperatures of 25°C or 68°C were identi-
fied, ranging from methane to alcohols to linear phthalate esters.
Six of the compounds identified are listed as suspected carcinogens;
vinyl chloride, trichloroethylene, benzene, phenol, chloroform, and
1,4-dioxane.

-------
                          SECTION  III

                       LITERATURE  SURVEY

A.   VOLATILIZATION PRODUCTS OF PLASTICS

A literature survey was conducted  to determine the potential
volatilization products from the plastics used to construct the
interiors of new automobiles.  The majority of the plastics used
for automobile interiors include ABS   (acrylonitrile-butadiene-
styrene), acrylic, polyethylene, polypropylene, polyurethane, and
PVC (polyvinyl chloride).  Plastics that are used in lesser
quantities include alkyds, cellulosics, epoxies, fluoroplastics,
melamine, noryl phenylene oxide-based resin, nylon, phenolic,
polycarbonate, reinforced polyeister, polystyrene, SAN  (styrene-
acrylonitrile), and thermoplastic polyester.  The uses of these
plastics are summarized in Table 1.

The volatilization products associated with these plastics were
determined in a series of studies conducted by Pustinger, Hodgson,
and co-workers of Monsanto Research Corporation.1"5 In these
studies, the off-gas products of a number of specific plastics
compounds were measured at 25°C and 68°C.  For the purpose of
this report, no attempt was made to quantify these emissions
because of varying sampling and analytical techniques used.  A
brief discussion of the off-gas products from specific plastic
compounds is given below.

1.   Aerylonitrile-Butadiene-Styrene (ABS)

In automobile interior construction, ABS finds extensive applica-
tion in dashboard and instrument panel components and is used in
conjunction with other plastics in seat assemblies, door and
quarter panels, armrest assemblies, seat belts, plated hardware,
vents and ducts, and as a structural base for assorted trim.

In an analysis of one type of commercial ABS polymer (Boltaron)
eight volatilization products were identified at 25°C and six
products at 68°C (Table 2).  In both cases unreacted styrene
monomer was the principal constituent.

In a study conducted by Harrison and Portwood,6 various ABS
materials were heated at temperatures of 49-90°C.  Again styrene
was the principal volatilization product, representing 95%  (by
weight) of the organics released.

-------
             TABLE  1.   SUMMARY OF USES OF PLASTICS IN AUTOMOBILE INTERIORS
         Plastics
                               Use
ABS (acrylonitrile-
  butadiene-styrene)
Acrylic

Epoxy

Phenolic

Polyester/glass

Polypropylene



Polyurethane
Dashboard, instrument panel components, seat assembly, door
  and quarter panels, armrest assemblies, seat belts, plated
  hardware, vents and ducts, structural base for assorted
  trim

Nameplates, dials, various instrument panel components

Adhesive for numerous components

Small quantity used as a sealant and adhesive

Heater and air conditioning housing

Door panels, heater and air conditioning housing, station
  wagon decks, seat backs, dash panel inserts, sun visor,
  filler panels and other trim

Cushioning material, trim, horn buttons, armrests, sun
  visor, crash pads
PVC  (polyvinyl chloride)
Seat padding, seat upholstery, head liners, crash pad, sun
  visor, armrests

-------
              TABLE 2.  ABS VOLATILIZATION PRODUCTS
                  At 25°C               At 68°C

             Methane               Methane
             Trichloroethylerie     Trichloroethylene
             Ethanol               Toluene
             n-Propanol            Xylene
             Toluene               Styrene
             Xylene                Methylstyrene
             Styrene
             Methylstyrene


2.   Acrylic

Acrylic plastics are used for nameplates, dials, and various
other instrument panel components.

In an analysis of Plex 55 acrylic, only one volatilization
product, methane, was identified at 25°C.  At 68°C, three off-gas
products were detected (Table 3).  In both cases only low concen-
trations of volatiles were noted.

      TABLE 3.  VOLATILIZATION PRODUCTS OF PLEX 55 ACRYLIC
                    At 25°C	At 68°C

                    Methane        Methane
                                   n-Propanol
                                   Benzene
3.   Epoxy
Epoxy resin adhesives are used throughout the interior of auto-
mobiles.

The literature yielded information on eight types of epoxy ad-
hesives that have been tested for volatilization products.  The
results of these analyses vary widely.  Several of the adhesive
compositions had as many as nine off-gas products, while one of
the compounds, epoxy Stycase 2651/catalyst II, was free of vola-
tilization products.

Although the results from these analyses were difficult to
quantify, the predominant volcitilization products at 25°C were
methane, ethanol, and xylene.  In at least two of the compounds
tested, xylene was detected in high concentrations.  At 68°C the
most common off-gas products were methane, ethanol, xylene, and
acetone.  A list of all possible volatilization products from
epoxy adhesives is given in Table 4.

-------
      TABLE  4.  VOLATILIZATION  PRODUCTS  FROM EPOXY ADHESIVES
              At  25°C
                                       At  68°C
      (5)  Methane
      (1)  1,1,1-Trichloroethane
      (1)  Trimethylhexane
      (1)  Ethylene
      (1)  Methanol
      (4)  Ethanol
      (3)  n-Propanol
      (1)  Isopropanol
      (1)  2-Methyl-l-propanol
      (2)  n-Butanol
      (1)  Diethyl ether
      (3)  Acetone
      (3)  2-Butanone
      (1)  4-Methyl-2-pentanone
      (1)  2-Methyl-4-pentanone
      (3)  Toluene
      (4)  Xylene
                               (5) Methane
                               (1) 1,1,1-Trichloroethane
                               (2) dij-Cg Hydrocarbons
                               (1) Ethylene
                               (1) Methanol
                               (5) Ethanol
                               (2) n-Propanol
                               (1) Isopropanol
                               (1) 2-Methyl-l-propanol
                               (2) n-Butanol
                               (1) Diethyl ether
                               (4) Acetone
                               (3) 2-Butanone
                               (1) 4-Methyl-2-pentanone
                               (1) 2-Methyl-4-pentanone
                               (3) Toluene
                               (4) Xylene
                               (1) Benzaldehyde
      Number in parentheses  denotes  the  number  of  epoxy  com-
      pounds tested  (out of  a  total  of 8) which produced this
      volatilization product.

4.   Melamine

Approximately twenty alcohols  and  aliphatic  and aromatic hydro-
carbons were identified as the volatilization products from two
melamine compounds.  The major off-gas compound at both  temperatures
was n-butanol, while xylene  was  also present in high concentrations
at 25°C  (Table 5).

5.   Phenolic

In the construction of automobile  interiors, phenolic resin is used
in small quantities as a sealant and adhesive.

Volatilization products from three commercial phenolic compounds
ranged from a mixture of seven aliphatic and aromatic hydrocarbons
and ketones to methane alone (Table  6).  The same  volatiles were
identified at 25°C and 68°C  with the exception  of  methane,  which
was not detected at 25°C.
6.
Polyester/Glass
Glass-reinforced polyesters are used in automobile  interiors  for
heater and air conditioner housings.

-------
   TABLE 5.  VOLATILIZATION PRODUCTS FROM TWO MELAMINE'SAMPLES
          At 25° C
          At 68°C
(2)  Methane
(1)  C^-Cg Hydrocarbons
(2)  C7-C8 Hydrocarbons
(1)  Cg-C}0Hydrocarbons
(2)  Ethanol
(2)  n-Propanol
(1)  2-Propanol
(1)  2-Methyl-l-propanol
(2)  n-Butanol
(1)  Benzene
(1)  Toluene
(1)  GS-CS Alkylbenzene
(2)  Xylene
(1)  Higher molecular weight
       alkylbenzenes
(1)  Methane
(2)  C^-Cg  Hydrocarbons
(2)  CJ-CQ  Hydrocarbons
(1)  C10  Hydrocarbons
(2)  Ethanol
(2)  n-Propanol
(1)  2-Propanol
(1)  2-Methyl-l-propanol
(2)  n-Butanol
(1)  Toluene
(2)  Xylene
(1)  C3-C5  Alkylbenzene
(1)  Higher molecular weight
      alkylbenzenes
    TABLE 6. VOLATILIZATION PRODUCTS OF PHENOLIC COMPOUNDS
                        At 2S°C and 68°C

                     (2)a Methane
                     (1)  C6-C7 Hydrocarbons
                     (1)  n-Propanol
                     (1)  Furfuraldehyde
                     (1)  Acetone
                     (1)  Methyl ethyl ketone
                     (1)  Benzene
                     (2)  Toluene
                     (2)  Xylene
                     (1)  Phenol


                     Number in parentheses
                    denotes the number of
                    phenolic compounds tested
                     (out of a. total of 3)
                    which produced this vola-
                    tilization product.

The volatilization products were identified in an analysis  of  two
reinforced polyester products are listed in Table 7.  Only  small
concentrations of acetone, benzene, and xylene were detected in
off-gas products from  both samples.

-------
   TABLE 7.  VOLATILIZATION PRODUCTS FROM TWO POLYESTER/GLASS
             REINFORCED SAMPLES


              At 25°C                       At 68°C

     C7-Saturated hydrocarbons     Methane
     2-Propanol                    Cy-Saturated hydrocarbons
     2-Methyl-2-propanol           n-Propanol
     2-Butanol                     2-Propanol
     Acetone                       2-Methyl-2-Propanol
     Benzene                       n-Butanol
     Toluene                       2-Butanol
     Xylene                        Benzene
                                   Toluene
                                   Xylene
                                   Cif-Alkylbenzene
7 .   Polypropylene

In authomobile interiors, reinforced polypropylene foam is used
in quarter and door panels, heater and air conditioning housings,
station wagon decks, seat backs, dash panel inserts, sun visors,
filler panels, and miscellaneous trim.  For many such applica-
tions, polypropylene is copolymerized with ethylene.

Emissions of volatilization products are reduced because unreacted
propylene monomer, amorphous polymer, and reaction diluents are
removed from the polypropylene during processing.  Five vola-
tilization products of Polypropylene 65-23 were identified (Table
8) .   With the exception of toluene, all of these volatile com-
pounds were C^-Cg alkenes and were found in low concentrations.
Emission species were quantitatively identical at both 25°C and
68°C.

           Table 8.  VOLATILIZATION PRODUCTS FROM
                     POLYPROPYLENE 65-23
                        At 25°C and 68°C

                    Butene
                    Methyl butene
                    Dimethyl butene
                    Trimethyl hexadiene
                    Toluene

-------
8.   Polyurethane

Flexible and rigid polyurethane foams and all types of  integral-
skin foams are the most widely used plastics in automobile in-
teriors.  Flexible and rigid foams account for nearly all cushion-
ing materials, while integral-skin polyurethanes are widely used
in the trim.  Flexible foams are used for horn buttons, armrests,
and sun visors.  Semirigid foams are used for crash pads.

Since so many different combinations of compounds are used in
polyurethane formulations, volatile emissions vary considerably
from one product to another.  A total of fifteen volatilization
products have been detected in the off-gas products from seven
commercial polyurethane compounds  (Table 9).  At 25°C, ten dif-
ferent volatilization products were identified, but only methane,
ethanol, n-butanol, toluene, and xylene were present in two or
more polyurethane samples.  At 68°C, only methane, ethanol,
toluene, and xylene were emitted by more than one of the samples.
Two of the polyurethanes tested, Spandex Lycra Polyurethane and
Polyurethane PR 15-35, were free of volatiles.

       TABLE 9.  VOLATILIZATION PRODUCTS FROM POLYURETHANES
             At 25°C
            At 68°C
     (4)  Methanol
     (3)  Ethanol
     (2)  n-Butanol
     (1)  Acetone
     (1)  Benzene
     (4)  Toluene
     (3)  Xylene
     (1)  CI-GS Alkylbenzenes
     (2)  2-Phenyl-2-propanol
     (1)  Acetophenone
(3)  Methane   .
(1)  Chloroform
(1)  Methanol
(2)  Ethanol
(1)  n-Butanol
(1)  2-Methyl-2-butanol
(1)  Acetone
(1)  Benzene
(3)  Toluene
(2)  Xylene
(1)  Cj-Cs  Alkylbenzenes
(1)  2-Phenyl-2-propanol
(1)  Acetophenone
(1)  1,4-Dioxane
(1)  n-Methyl morpholine
      Number in parentheses denotes the number of polyurethane
      compounds tested (out of a total of 7) which produced
      this volatilization product.
      Possibly carcinogenic.

-------
 9.    Polyvinyl  Chloride  (PVC)

 In  thQ  construction  of automobile  interiors, PVC  sheet and  foam
 find  a  wide  variety  of applications;  they are  second only to the
 polyurethanes in  total consumption.   PVC foam  is  used primarily
 for seat padding  and undercovering, and PVC sheet is used for
 seat  upholstering, head  liners,  crash pad skin, and facing  for
 rear  window  panels,  door inner panels, sun visors, and armrests.

 An  analysis  of  Boltaron  6200, Rigid PVC Type I for volatiles de-
 tected  only  three hydrocarbons at  68°C, and none  at 25°C.   How-
 ever, it is  suspected that  unreacted  vinyl chloride monomer may
 be  a  volatilization  product of the plasticized PVC found in
 automobile interiors.  It has been estimated7 that vinyl chloride
 levels  in PVC resins may range as  high as 8000 ppm, although
 unreacted monomer concentrations are  usually in the neighborhood
 of  50-1000 ppm.   In  finished products, this figure is probably
 reduced to 5-20 ppm.

 Plasticizer  volatilization  is a  recognized attribute of PVC
 products, and has been cited as  the major cause of windshield
 fogging and  "new  car smell."8  In  automobile interior components,
 the linear phthalates are the most commonly used  plasticizers,
 possessing better low-temperature  properties than the more  uni-
 versally popular  branched phthalates.  Linear phthalate esters
 are based on linear  C6-C10  alcohols,  and normally comprise  15-50%
 of a  PVC product.

 Phthalate ester concentrations on  the order of 0.3 yg/liter have
 been measured in  automobile interiors.  However,  this testing was
 conducted on a  1972  automobile and it is not known whether
 branched or  linear phthalate plasticizers were involved.  The
 linear  phthalates are known to be  50-80% less volatile than their
 branched counterparts.

          TABLE 10.  VOLATILIZATION PRODUCTS FROM PVC
             At 25°C
        At 68°C
     Vinyl chloride
     Linear phthalate esters
Methane
C1+ -C 5 Hydrocarbon
Vinyl chloride
Toluene
Linear phthalate esters
10.  Polystyrene and Styrene-Acrylonitrile  (SAN)

Although no information was available on the volatilization
products of polystyrene and styrene-acrylonitrile, data from ABS
                                10

-------
materials suggest the possibility of unreacted styrene monomer
volatilization.

11.  Nylon, Polycarbonate, and Polyethylene

Tests conducted on polyethylene film and various nylon and
polycarbonate products indicate that these materials are free of
volatiles.

12.  Alkyds, Cellulosics, Fluoroplasticsy NORYL Phenylene-Oxide-
     Based Resin/ and Thermoplastic Polyester

No information was found dealing with the ambient volatilization
products of these materials.  However, these compounds find very
limited application in automobile interiors and probably do not
contribute significantly to organic pollutant levels.

B.   SUSPECTED CARCINOGENIC COMPOUNDS

One of the objectives of this project was to identify those
volatilization products that are suspected carcinogens.  Table 11
lists all volatilization products identified in the previous
section with the suspected carcinogen compounds identified.9

   TABLE 11.  VOLATILIZATION PRODUCTS FROM PLASTICS USED IN
              THE INTERIOR OF 1975 AUTOMOBILES	

           Volatilization products at 25°C and 68°C

          Methane                Diethyl ether
          Trichloroethane        Furfuraldehyde
          Trimethylhexane        Acetone
          Ck-C1Q Hydrocarbons    Methyl ethyl ketone
          Ethylene      a        2-Butanone
          Vinyl chloride   g     4-Methyl-2-pentanone
          Trichloroethylene      2-Methyl-4-pentanone
          Butene                 Benzene3
          Methylbutene           Toluene
          Dimethylbutene         Xylene
          Trimethylhexadiene     Styrene
          Methanol               Methylstyrene
          Ethanol                Ci-Cs Alkylbenzenes
          2-Propanol             Higher MW alkylbenzenes
          2-Methyl-2-propanol    2-Phenyl-2-propanol
          n-Butanol              Acetophenone
          2-Butanol              Linear phthaltate esters
                  Additional products at 68°C
          Chloroform3            Benzaldehyde
          1,1,1-Trichloroethane  if4-Dioxanea
          2-Methyl-2-butenal


           Suspected carcinogenic compounds9
                               11

-------
                          SECTION IV

                      SAMPLING PROCEDURES

A.   AUTOMOBILES SAMPLED

Arrangements were made with various automobile dealers in Dayton,
Ohio to sample new 1975 model vehicles for vinyl chloride monomer
 (VCM).  The test vehicles were selected to insure a broad spec-
trum of vehicle types and manufacturers were sampled.  Subcompact
and compact cars were tested because the ratio of plastic to
interior volume was high and would result in a worst-case organic
concentrations.

The seven 1975 automobiles selected for the test were a Ford
Pinto, Dodge Dart Sport, American Motors Gremlin, Volkswagen
Rabbit  (Hatchback), General Motors Vega, General Motors Chevrolet
 (Station Wagon), and a Datsun 710.  A description of each auto-
mobile tested is included in the data sheets in Appendix A.  Each
data sheet describes the interior and exterior colors of the
vehicle as well as the date the vehicle was assembled and the
data the samples were taken.

B.   SAMPLE COLLECTION

In order to quantitatively sample for VCM charcoal tubes were
used for collection.

Charcoal tubes purchased from SKC, Inc. (Pittsburgh, Pa.) (Figure
1) were used to collect VCM in the interior of each test auto-
mobile.  Each glass collection tube was filled with 100 mg of
charcoal.  Tests were performed by drawing 3 liters of air
through the tube at 50 ml/min.  The tubes were then capped,
stored in a freezer at -20°C, and transported to the laboratory
for VCM analysis by an extraction/gas chromatographic technique.

Sampling runs were made with personal-type air samplers.  Two
electric Telmatic Air Samplers (Bendix Models 150 and C115)  were
modified with remote controls so they could be activated from
outside of the test vehicle.  The batteries used to power the
pumps were also located outside of the vehicle.  Each sampling
pump was calibrated and adjusted for a constant flow rate of
50 ml/min.   The sampling tubes were placed on the front seat next
to the sampling pump and connected by short tubes to minimize the
exposure of the sample to tubing materials before the gases got
to the carbon sorbent.
                               12

-------
OJ
                       N.I.O.S.H. APPROVED SEALING CAPS
                       SEAL TUBE WITHOUT SAMPLE CONTAMINATION
GLASS WOOL


FOAM SEPARATOR
OF UNIFORM POROSITY
                                                                                        PRECISION LOCK-SPRING
                                                                                 HOLDS CHARCOAL LAYERS IN PLACE
                                                                              THUS PREVENTING SAMPLE CHANNELING
                                                                                 	SAMPLE LAYER
                                                                                           100mg. OF CHARCOAL

                                                                                 BACK-UP CHARCOAL LAYER, 50mg.

                                                                                         TIP PRECISION SEALED
                                                                                    FOR SAFE AND EASY BREAKING
                                                                                       TO DESIRED OPENING SIZE
                       PATENT PEN DING
                            Figure  1.   Charcoal  tube  used  to  collect  VCM  sample.

-------
Each sampling package was equipped with a thermistor to measure
the air temperature inside the test vehicle.  An additional
thermistor was used to measure the ambient temperature outside of
the automobile.

The sample collection package was placed on the front seat,
either on the driver's side or the passenger's side, wherever it
appeared that the sun would heat the seat the most.  It was
reasoned that sampling the hottest seat during the hot summer
time should establish a worst-case condition for pollutant con-
centrations.  After placing the sampling package and inserting
the collection tubes, the control wires for the samples were then
run through the window, which was quickly rolled up to the top
position.  The seal at the top of the window was such that the
window could be tightly closed and still allow the wires to pass
through.

A period of at least 30 minutes was allowed to pass before sampling
began in order to help reestablish equilibrium inside the car.
Being aware that this time might not be sufficient to reach
equilibrium, every effort was made to open the door carefully,
slide the sampler in quickly, and close the door with minimum air
interchange.  This was always done from the downwind side to
minimize ventillation in the car during this time.  Unless over
one-half of the air was changed during the sampler placement, the
concentration read should be at least one-half of the maximum
level, even if no additional vinyl chloride diffused out into the
air space during the one-half hour waiting period before sampling.
The actual amount of air interchange would be expected to be con-
siderably less than this.

The sampling pumps were activated until approximately 3 liters of
air had been sampled.  The pumps were then turned off, and the
collection tubes were quickly prepared for storage as previously
described.  The sampling conditions and the temperature of the
seat,  interior air, and exterior air are also shown on the data
sheets in Appendix A.
                               14

-------
                           SECTION V

                        SAMPLE ANALYSIS

The charcoal tubes were analyzed for VCM according to the tech-
nique described by the National Institute of Occupational Safety
and Health  (NIOSH), Method No. 178.10  This procedure is given in
Appendix B.  Briefly, this method describes a procedure for
determining quantitatively the amount of vinyl chloride in air by
adsorption on charcoal and subsequent analysis by carbon disul-
fide extraction and gas chromatographic detection.  This method
also describes a procedure for determining the desorption ef-
ficiency of VCM from the charcoal by carbon disulfide extraction.

To determine the desorption efficiency, a standard solution of
VCM and carbon disulfide was first prepared.  A known concentra-
tion of 99.9% pure VCM was dissolved in a known volume of carbon
disulfide as described in the Volumetric Method, Section 9.1 of
NIOSH Method No. 178.10  Various volumes of this solution were
injected into a gas chromatograph equipped with a flame ioniza-
tion detector and the response was recorded.  A standard curve
was prepared by plotting the known quantity of VCM versus the
peak area recorded from the gas chromatograph response.

Next, a known concentration of VCM vapor was injected with a gas-
tight syringe into a Tedlar* bag filled with a known volume of
air.  A charcoal tube was then attached to the bag outlet and a
known volume of this air-VCM mixture was drawn through the char-
coal tube.  By using the air temperature and pressure, volume of
air sampled, and VCM concentration in the Tedlar bag, the quantity
of VCM absorbed by the charcoal tube could be calculated.

The charcoal was then extracted with carbon disulfide as described
in NIOSH Method No. 178. 10  Known volumes of the extract were
injected into the gas chromatograph and the response recorded.
The peak areas obtained from these samples were compared to the
standard curve to determine the quantity of VCM in the sample.
The desorption efficiency was determined by dividing the quantity
of VCM measured from the extract by the quantity of VCM calcu-
lated to be adsorbed in the charcoal tubes.

The desorption efficiency was measured three times using three
concentrations of standard VCM gases.  The standard gases had VCM
*Fluorodynamics,  Inc., Newark, Delaware.

                              15

-------
concentrations of 1  ± 0.1 ppm, 10 ± 0.5 ppm, and 50+1 ppm.
These mixtures were  purchased and certified by MG Scientific
 (Kearny, N.J.).  For the batch of charcoal tubes used throughout
this study, the desorption efficiency of VCM from the charcoal
was determined by carbon disulfide extraction to be 31%, 31%,
and 30% — for an average of 31% — and showed very good repro-
ducibility.  Though  this percentage is not high similar measure-
ments by other investigators have obtained readings of 18% for
this measurement.  Factors such as polymerization of VCM on the
carbon and adsorption on vessel walls are suspected as being the
primary causes for low desorption efficiencies when dealing with
small amounts of VCM.  These measurements were done at room
temperature since the sample analyses were also done at these
same conditions.

The minimum detectable limit for this gas chromatographic system
for vinyl chloride was 0.75 ng per 5 yl injection.  This resulted
in a minimum atmospheric detection limit of 0.05 ppm for the
sampling technique previously described.

The charcoal in the  sampling tubes was divided into two parts
 (see Figure 1).  The front half of the tube contained approxi-
mately 2/3 of the charcoal, while the back half contained the
rest.  After having  a gas sample containing 500 micrograms of VCM
passed through the tube, analysis of the back half of the tube
revealed no VCM, meaning that the front half of the tube was
100% efficient at 23°C.

The question as to expected adsorption efficiency at higher
temperatures might be raised.  The actual sorption temperatures
inside the cars ranged from 43°C to 66°C.  To check the sorption
efficiency of the carbon at the higher temperatures, the ratio of
the equilibrium static absorptive capacity per unit weight of
carbon at 65°C as compared to that at 25°C was calculated using
the method recommended by Nelson and Harder.11  This calculation
indicates that the equilibrium static sorptive capacity for carbon
at 65°C should be 18 percent as great as it is at 25°C.  This is
definitely more than adequate since the carbon in the first half
of the tube completely adsorbed 500 micrograms of VCM during the
test at 25°C and the three liter sample containing 1.2 ppm of
VCM taken at elevated temperature contained only 2.6 micrograms
of this material.

The gas chromatograph was equipped with a flame ionization
detector and a 1.83 m x 0.21 cm column, packed with 80-100 mesh
Chromosorb 102.   A nitrogen carrier gas was used with a flow rate
of approximately 30 ml/min.

Hydrogen (at 10 psig) was flowed at 25 ml/min and air (at 20
psig)  was flowed at  110 ml/min to the flame ionization detector.
The syringe injector port was maintained at 129°C, the oven at
127°C,  and the detector at 119°C.

                               16

-------
                           SECTION VI

                     RESULTS AND DISCUSSION

The results of the analyses of the charcoal tubes are shown in
Table 12.  The table indicates the make and model of the auto-
mobile tested, the temperature of the ambient air, interior air
and seat surface, the number of days between the vehicle assembly
and sampling dates, and the concentration of VCM detected.  If
VCM was not detected, then the VCM concentration was below the
minimum detection limit of 0.05 ppm for the analytical system.

VCM was detected in only two of the seven automobiles tested, the
Ford Pinto and the Dodge Dart.  The higher concentration of VCM
(1.2 ppm) found in the Ford Pinto may be due to a combination of
the higher seat surface temperature (66°C) compared to the other
vehicles tested and the relatively shorter period of time between
vehicle assembly and sampling dates.

The concentration of VCM in the interior of a new automobile may
be dependent on how frequently the vehicle is ventilated.  Since
it was not possible to control or quantify this variable, this
could explain why VCM was detected in the Dodge Dart and not in
the other five vehicles of comparable age.  This conclusion is
based on the assumption that the ratio of the vehicle interior
volume to the quantity of polyvinyl chloride plastic is the same
in each test vehicle.  Data were not available to substantiate
this assumption.

Since the level of VCM in 5 out of 7 of the test vehicles was
below the detection limits of the analytical system, it was not
possible to quantitatively develop a relationship between VCM
volatilization emissions and the temperature of the seats or the
age of the test vehicle.  It also appeared that the interior and
exterior colors of the automobile had no effect on the VCM emis-
sions.  The Ford Pinto had a black interior, but the Dodge Dart
had a white interior.  The darker interiors did, as expected,
result in higher seat temperaitures than did the lighter colored
interiors.

The temperature to which the PVC plastic in the car is exposed
should affect the rate at which VCM is emitted and the concen-
tration level measured.  A comparison of the seat temperatures
and the VCM levels recorded in Table 12 does not show any cor-
relation since all five of the cars with no measurable VCM con-
centration had higher seat temperatures than the Dodge Dart did.

                              17

-------
                        Table 12.   VCM  IN THE  INTERIOR OF 1975 AUTOMOBILES
CO

Temperature ,
1975 Automobile sampled
Ford Pinto
Dodge Dart: Front seat
Back seat
American Motors Gremlin
Volkswagen Rabbit
(Hatchback)
General Motors Vega
General Motors Chevrolet
(Station wagon)
Datsun 710
Ambient
air
36
27
27
33
31
33
33

30
Interior
air
60
50
50
44
43
45
45

43
°C
Seat
surface
66
46
46
52
55
49
49

50
Number of
days since
vehicle
assembly
32
102
102
>60
70
>30
120

60
' Vehicle color „
Exterior
Drk. red
Drk. red

Dr. Grn.
Red
Lt. blue
Lt. brn.

Drk. red
Interior
Black
White

Drk . Grn .
Black
Lt. blue
Black

White
VCM
oncentration,
ppm
1.2
0.4
0.7
<0.05a
<0.05
<0.05
<0.05

<0.05
          Minimum detectable limit of the analytical system.

-------
PVC is a very stable material.  Even when it does slowly decompose
with age, it does not form more VCM.  Hence the only VCM in the
PVC in cars is that which was originally unreacted.

As the literature search revealed, the quantity of unreacted VCM
remaining in a finished product constructed of PVC ranges from 5-
20 ppm.  An average automobile contains about 25 pounds of PVC.
Therefore, the quantity of VCM trapped in the plastic would com-
monly be expected to range from 55 to 225 rag.  If all of the VCM
were volatilized at once into an automobile with 3 cubic meters
of air space, this would result in VCM concentrations ranging
from 7.2 to 29 ppm.

In conclusion, the data obtained in this study indicate that VCM
concentrations in 1975 automobile interiors were in most cases
below the recommended NIOSH standard of one ppm even in cars
which were unventilated.  With ventilation any car which contained
a significant concentration, such as 1 ppm, would lose its VCM
rather rapidly since the car would not be expected (by material
balance)  to be able to reestablish this concentration more than
7 to 29 times.

It should also be mentioned, however, that this was a preliminary
screening study which was not intended to be rigorous or compre-
hensive.   Though a variety of cars was sampled, data were collected
from only one of each kind.  Statistical variations within models
were not examined in this study.  Also, the effect of time between
sampler placement in the car and the start of sampling was not
investigated in this study.  Due to the precautions taken (mini-
mization of time the car door was open, entry from downwind side),
the authors feel that this effect should be small, but no quali-
tative data on tis effect are available.  Finally, the NIOSH
method for vinyl cloride is intended primarily for use at room
temperature.  This method was used for this preliminary study
because it is reasonably well defined, is familiar to workers in
this field, and did not require any further development work.

If a more rigorous study were to be performed, the numbers of
cars per model which would be sampled should be increased and the
effects of equilibration time could be investigated.  Though the
authors feel that the results obtained in this study combined
with the limited amount of VCM in PVC now being produced indicate
that vinyl chloride in automobile interiors should not pose a
significant health hazard, some consideration might be given to
performing additional study to confirm this in 1976 cars in a
more rigorous, comprehensive manner.
                              19

-------
                           REFERENCES

1.   Pustinger, J. V., F. N. Hodgson, and W. D. Ross.  Identifi-
     cation of Volatile Contaminants of Space Cabin Materials.
     Aerospace Medical Research Laboratory, Wright-Patterson Air
     Force Base, Dayton, Ohio  AMRL-TR-66-53.  1966.

2.   Pustinger, J. V. and F. N. Hodgson.  Identification of Vola-
     tile Contaminants of Space Cabin Materials.  Aerospace
     Medical Research Laboratory, Wright-Patterson Air Force Base,
     Dayton, Ohio.  AMRL-TR-67-58.  1967.

3.   Pustinger, J. V. and F. N. Hodgson.  Identification of Vola-
     tile Contaminants of Space Cabin Materials.  Aerospace
     Medical Research Laboratory, Wright-Patterson Air Force
     Base, Dayton, Ohio.  AMRL-TR-68-27.  1968.

4.   Pustinger. J. V., F. N. Hodgson, and J. E. Strobel.  Identi-
     fication of Volatile Contaminants of Space Cabin Materials.
     Aerospace Medical Research Laboratory, Wright-Patterson Air
     Force Base, Dayton, Ohio.  AMRL-TR-29-18.   1969.

5.   Pustinger, J. V., F. N. Hodgson, J. E. Strobel, and
     R. L. Evers.  Identification of Volatile Contaminants of
     Space Cabin Materials.  Aerospace Medical Research Laboratory,
     Wright-Patterson Air Force Base, Dayton, Ohio.  AMRL-TR-69-71.
     1969.

6.   Harrison, J. C. and R. Portwood.  New Performance Properties
     of Thermoplastics.  Plastics and Polymers.  December 1970.
     p. 422.

7.   Preliminary Assessment of the Environmental Problems Associ-
     ated with Vinyl Chloride and Polyvinyl Chloride.  Office of
     Toxic Substances, Environmental Protection Agency, Washington.
     EPA-560/4-74-001 (PB 239 110).  September 1974.

8.   Mieure, J. P. and M. W. Dietrich.  Determination of Trace
     Organics in Air and Water.  J. Chromatographic Science.
     11:559-570, November 1973.

9.   Federal Register.  4_0_(121) Part 11:106.  June 23, 1975.
                               20

-------
10.   NIOSH Manual of Analytical Methods.   U.S.  Department of Health,
     Education, and Welfare, Cincinnati,  Ohio.   HEW Publication
     No.  (NIOSH)  75-121.   1974.

11.   Nelson, G. O., and Harder, C.  A.   Respirator Cartridge Ef-
     ficiency Studies.  V.  Effect of Solvent Vapor.  Amer. Ind.
     Hyg.  Ass. J.  35:391-410,  1974.
                                21

-------
                        APPENDIX A

                        DATA SHEETS
                TABLE A-l.  SAMPLING DATA
Automobile
     Manufacturer:
     Model:

     Colors:

     Location:
     Date assembled:
     Date of arrival:
     Date of sampling:

Sampling Conditions

     Pump:
     Tube:
     Ambient temperature:
     Interior air temperature:
     Seat surface temperature:
     Last ventilated time:
     Flow rate:
     Total volume:
     Location sampled:
Remarks
Ford Motor Co.
1975 Pinto
2-Door sedan
Exterior dark red
Interior black
Kettering, Ohio
5-18-75
5-28-75
6-19-75
Personnel air
Sampling pump
Bendix Model 150
SKC charcoal tube
36°C
60°C
66°C
6-18-75; 3:00 P.M.
50 ml/min
3 liters
Front seat
Back seat
     Samplers placed in car at 2:00 P.M.
     2:30 P.M. by remote switch.
       Sampling began at
                            22

-------
                  TABLE A-2.  SAMPLING DATA
Automobile
     Manufacturer:
     Model:
     Colors:
     Location:
     Date assembled:
     Date of arrival:
     Date of sampling:

Sampling Conditions
     Pump:
     Tube:
     Ambient temperature:
     Interior air temperature:
     Seat surface temperature:
     Last ventilated time:

     Flow rate:
     Total volume:
     Location sampled:
Chrysler Corp.
1975 Dart Sport
Exterior dark red/white
  vinyl top
Interior ivory white
Dayton
4/1/75
4/15/75
7/15/75


Bendix model 150
SKC charcoal tube
27.5°C
50°C
46°C
Approx. 30 min prior to
  sampling
50 ml/min
3 liters
Passenger's seat
Driver's seat
                  TABLE A-3.  SAMPLING DATA
Automobile
     Manufacturer:
     Model:
     Colors:

     Location:
     Date assembled:
     Date of arrival:
     Date of sampling:

Sampling Conditions
     Pump:
     Tube:
     Ambient temperature:
     Interior air temperature:
     Seat surface temperature:
     Last ventilated time:
     Flow rate:
     Total volume:
     Location sampled:

Remarks
American Motors Corp.
Gremlin
Exterior dark green
Interior dark green
Dayton, Ohio
No data
5/25/75
7/23/75


Bendix model C115
SKC charcoal tube
33°C
44°C
52°C
30 min prior to sampling
50 ml/min
3 liters
Driver's seat
     Battery went down after 40 min of sampling time
                             23

-------
                 TABLE A-4.  SAMPLING DATA
Automobile
     Manufacturer:
     Model:

     Colors:

     Location:
     Date assembled:
     Date of arrival:
     Date of sampling:

Sampling Conditions

     Pump:
     Tube:
     Ambient temperature:
     Interior air temperature;
     Seat surface temperature:
     Last ventilated time:
     Flow rate:
     Total volume:
     Location sampled:

Remarks
Volkswagen
1975 Sedan
2-Door hatchback
Exterior red
Interior black
Dayton, Ohio
5/15/75
7/2/75
7/24/75
Bendix model 150
SKC charcoal tube
31°C
43°C
55°C
30 min prior to sampling
50 ml/min
3 liters
Driver's seat
     Pump was standard at 1:45 P.M.
                 TABLE A-5.  SAMPLING DATA
Automobile

     Manufacturer:
     Model:
     Colors:

     Location:
     Data assembled:
     Date of arrival:
     Date of sampling:

Sampling Conditions

     Pump:
     Tube:
     Ambient temperature:
     Interior air temperature:
     Seat surface temperature:
     Flow rate:
     Total volume:
     Location sampled:
General Motors Corp,
1975 Vega
Exterior light blue
Interior light blue
Dayton, Ohio
No data
7/1/75
7/25/75
Bendix model 150
SKC charcoal tube
33°C
45°C
49°C
50 ml/min
3 liters
Driver's seat
                            24

-------
                 TABLE A-6.  SAMPLING DATA
Automobile
     Manufacturer:
     Model:

     Colors:
     Location:
     Date assembled:
     Date of arrival:
     Date of sampling:

Sampling Conditions

     Pump:
     Tube:
     Ambient temperature:
     Interior air temperature
     Seat surface temperature
     Last ventilated time:
     Flow rate:
     Total volume:
     Location sampled:
General Motors Corp.
1975 Chevrolet
Station wagon
Exterior white top w/wood
  grain sides
Interior black
Dayton, Ohio
4/1/75
4/15/75
7/29/75
Bendix model 150
SKC charcoal tube
33°C
45°C
49°C
30 minutes
50 ml/min
3 liters
Passenger's seat
                  TABLE A-7.  SAMPLING DATA
Automobile

     Manufacturer:
     Model:
     Colors:

     Location:
     Date assembled:
     Date of arrival:
     Date of sampling:

Sampling Conditions

     Pump:
     Tube:
     Ambient temperature:
     Interior air temperature:
     Seat surface temperature;
     Last ventilated time:
     Flow rate:
     Total volume:
     Location sampled:
Datsun
1975 Datsun 710
Exterior dark red
Interior white
Dayton, Ohio
6/1/75
6/15/75
7/30/75
Bendix model 150
SKC charcoal tube
30°C
43°C
50°C
30 min prior to sampling
50 ml/min
3 liters
Driver's seat
                            25

-------
                             APPENDIX B

     SAMPLING AND ANALYSIS  OF VINYL CHLORIDE IN  AIR10



                      VINYL CHLORIDE  IN AIR

                     NIOSH Analytical  Method
Analy te :



Matrix:
Procedure :
Vinyl Chloride Method No.:
(Chloroethene ,
Chloroethylene)
Range:
Air
Adsorption on charcoal,
P&CAM #178


0.2-1500 ng
per injection

               desorption with carbon
               disulfide, GC

 Date Issued:   9/3/74                   Precision:       Unknown

 Date Revised:  10/15/74                 Classification:  D (Operational)


1.  Principle of  the Method

    1.1  A known  volume of air is drawn through a charcoal tube to trap the
         vinyl  chloride present.

    1.2  The charcoal in the tube is transferred to a small vial containing
         carbon disulfide where the vinyl chloride is desorbed.

    1.3  An aliquot of the desorbed sample is  injected into a gas chroma-
         tograph.

    1.4  The area of the resulting peak is determined and compared with
         areas  obtained from the injection of  standards.

2.  Range and Sensitivity

    2.1  The minimum detectable amount of vinyl chloride was found to be
         0.2 nanograms per injection at a 1 x  1 attenuation on a gas
         chromatograph.

    2.2  At the recommended sampling flow rate of 50 ml/rain, the total
         volume to be sampled should not exceed 5.0 liters.  This value
         is the volume of air containing 200 ppm of vinyl chloride which
         can be sampled before a significant amount of vinyl chloride
         is found on the backup section.  (The charcoal tube consists
         of two sections of activated charcoal separated by a section
         of urethan foam. (See Section 6.2.1)   If a particular atmosphere
                                   26

-------
         is suspected of containing a high concentration of contaminants
         and/or a high humidity is suspected, the sampling volume should
         be reduced by 50%.

3.  Interferences

    3.1  When the amount of water in the air is so great that condensation
         actually occurs in the tube, organic vapors will not be trapped.
         Preliminary experiments indicate that high humidity severely
         decreases the capacity of the charcoal for organic vapors.

    3.2  When two or more substances are known or suspected to be present
         in the air, such information, including their suspected identities,
         should be transmitted with the sample since these compounds may
         interfere with the analysis for vinyl chloride.

    3.3  It must be emphasized that any compound which has the same
         retention time as vinyl chloride at the operation conditions
         described in this method is an interference.  Hence, retention
         time data on a single column, or even on a number of columns,
         cannot be considered as proof of chemical identity.  For this
         reason it is important that a sample of the bulk material
         be submitted at the same time so that identity(ies) can be
         established by other means.

    3.4  If the possibility of Interference exists, separation conditions
         (column packing, temperature, etc.) must be changed to circumvent
         the problem.

4.  Precision and Accuracy

    The precision and accuracy of the total sampling and analytical method
    have not been determined.

5.  Advantages and Disadvantages of the Method

    5.1  The sampling device is small, portable, and involves no liquids.
         Interferences are minimal, and most of those which do occur can
         be eliminated by altering chromatographic conditions.  The tubes
         are analyzed by means of a quick, instrumental method.  The method
         can also be used for the simultaneous analysis of two or more
         components suspected to be present in the same sample by simply
         changing gas chromatographic conditions from isothermal to a
         temperature-programmed mode of operation.
                                   27

-------
    5.2  One disadvantage of the method is that the amount of sample which
         can be taken is limited by the number of milligrams that the tube
         will hold before overloading.  When the sample value obtained for
         the backup section of the charcoal trap exceeds 20% of that found
         on the front section, the possibility of sample loss exists.
         During sample storage, volatile compounds such as vinyl chloride
         will migrate throughout the tube until equilibrium is reached.  At
         this time, 33% of these compounds will be found in the backup
         section.  This may lead to some confusion as to whether sample
         loss has occurred.  This migration effect can be considerably
         decreased by shipping and storing the tubes at -20°.

    5.3  The precision of the overall method is limited by the reproduci-
         bility of the pressure drop across the tubes.  This drop will
         affect the flow rate and cause the volume to be imprecise,
         because the pump is usually calibrated for one tube only.

6.   Apparatus

    6.1  An approved and calibrated personal sampling pump for personal
         and area samples whose flow can be determined accurately at
         50 milliliters per minute.

    6.2  Charcoal tubes:  glass tube with both ends flame sealed, 7  cm
         long with a 6-mm O.D. and a 4-mra I.D., containing 2 sections of
         20/40 mesh activated coconut charcoal separated by a 2-mm portion
         of urethan foam.  The activated charcoal is prepared from coconut
         shells and is fired at 600°C prior to packing to remove material
         possibly absorbed on charcoal.  The primary absorbing section
         contains 100 mg of charcoal, the backup section 50 mg.  A 3-mm
         portion of urethan foam is placed between the outlet end of the
         tube and the backup section.  A plug of silylated glass wool is
         placed in front of the absorbing section.  The pressure drop
         across the tube must be less than one inch of mercury at a  flow
         rate of 1 £/min.

    6.3  Gas chromatograph equipped with a flame ionization detector.

    6.4  Stainless steel column (20 ft x 1/8 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 separations may be used.

    6.5  A mechanical or electronic integrator or a recorder and some
         method for determining peak area.

    6.6  Two-mi vials which can be sealed with caps containing teflon-
         lined silicone rubber septa.

    6.7  Microliter syringes:  10-pJl, and convenient sizes for making
         standards.
                                   28

-------
    6.8  Gas-tight syringes:  1-nfe , with open/close valve.

    6.9  Pipets:  0.5-mfc delivery pipets or 1.0-nA type graduated in
         0.1-nfc increments.

    6.10 Volumetric flasks:  10~mfc  or convenient sizes for making standard
         solutions.  It is preferable to have plastic stoppers for the
         volumetric flasks.

7.  Reagents

    7.1  Spectroquality carbon disulflde.

    7.2  Vinyl chloride, lecture bottle, 99.9% minimum purity.

    7.3  Toluene, chromatographic quality.

    7.4  Bureau of Mines Grade A helium.

    7.5  Prepurified hydrogen.

    7.6  Filtered compressed air.

8.  Procedure

    8.1  Cleaning of Equipment.  All glassware used for the laboratory
         analysis should be detergent washed and thoroughly rinsed with
         distilled water.

    8.2  Calibration of Personal Pumps.  Each personal pump must be
         calibrated with a representative charcoal tube in the line.  This
         will minimize errors associated with uncertainties in the sample
         volume collected.

    8.3  Collection and Shipping of Samples

         8.3.1  Immediately before  sampling, the ends of the tube are
                broken to provide an opening at least one-half the
                internal diameter of the tube (2 mm).

         8.3.2  The smaller section of charcoal is used as a backup and
                is positioned nearest the sampling pump.

         8.3.3  The charcoal tube is placed in a vertical position during
                sampling to prevent "channelling" of the charcoal.

         8.3.4  Air being sampled is not to be passed through any hose
                or tubing before entering the charcoal tube.
                                   29

-------
     8.3.5  Bulk air samples (i.e., samples of 10-20 liters of the
            air in the environment) are taken along with personal
            samples.

     8.3.6  The flow, time, and/or volume must be measured as
            accurately as possible.  The sample is taken at
            a flow rate of 50 ml/min.  The maximum volume to
            be sampled should not exceed 5.0 liters (See
            Section 2.2).
     8.3.7
The temperature and pressure of the atmosphere
being sampled is measured and recorded.
     8.3.8  The charcoal tubes are capped with the supplied
            plastic caps immediately after sampling.  Under no
            circumstances are rubber caps to be used.

     8.3.9  One tube is handled in the same manner as the
            sample tube (break, seal, and transport), except that
            no air is sampled through this tube.  This tube is
            labeled as a blank.

     8.3.10 Capped tubes are packed tightly before they are
            shipped to minimize tube breakage during transport
            to the laboratory.  If the samples will spend a day
            or more in transit, cooling (e.g., with dry ice)
            is necessary to minimize migration of vinyl chloride
            to the backup section.

     8.3.11 Samples received at the laboratory are logged in and
            immediately stored in a freezer (around -20°) until time
            for analysis.  Samples may be stored in this manner for
            long periods of time with no appreciable loss of vinyl
            chloride (2 months).  Even around -20°C, vinyl chloride
            will equilibrate between the two sections of charcoal,
            i.e., will migrate to the backup section.  This
            phenomenon is observable after two weeks and may be
            confused with sample loss after 1 to 2 months.

8.4  Analysis of Samples

     8.4.1  Preparation and Desorption of Samples.  In preparation
            for analysis, each charcoal tube is scored with a file
            in front of the first section of charcoal and broken open.
            The glass wool is removed and discarded.  The charcoal in
            the first (larger) section is transferred to a small vial
            containing 1 ml of carbon disulfide. (Note: the addition
            to the CS2 is important.)  The vial is topped with a
                               30

-------
            septum cap  (See Section 6.6).  The separating section
            of foam is  removed and discarded; the second section
            is transferred to another small vial containing 1 ml
            of CS2•  These two sections are analyzed separately.
            Tests indicate that desorption is complete in 30 minutes
            if the sample is agitated occasionally during this period.
            In any case samples should be analyzed within 60 minutes
            after addition to CS2-

     8.4.2  GC Conditions.  The typical operating conditions for the
            gas chromatograph are:

            1.  40 cc/min (80 psig) helium carrier gas flow
            2.  65 cc/min (20 psig) hydrogen gas flow to detector
            3.  500 cc/min (50 psig) air flow to detector
            4.  230°C injector temperature
            5.  230°C manifold temperature (detector)
            6.  60°C isothermal column temperature (oven).

     8.4.3  Injection.  The first step in the analysis is the injection
            of the sample into the gas chromatograph.  To eliminate
            difficulties arising from blowback or distillation within
            the syringe needle, one should employ the solvent flush
            injection technique.  The 10-u£ syringe is first flushed
            with solvent several times to wet the barrel and plunger.
            Two microliters of solvent are drawn into the syringe to
            increase the accuracy and reproducibility of the injected
            sample volume.  The needle is removed from the solvent
            and the plunger is pulled back about 0.4 \&  to separate the
            solvent flush from the sample with a pocket of air to be
            used as a marker.  The needle is then immersed in the
            sample, and a 5-y?,  aliquot is withdrawn to the 7.4 y£ mark
            (2 p£  solvent + 0.4 y£ air + 5 \iH sample = 7.4 u£).  After
            the needle is removed from the sample and prior to injection
            the plunger is pulled back a short distance to minimize
            evaporation of the sample from the tip of the needle.
            Duplicate injections of each sample and standard are made.
            No more than a 3% difference in area is to be expected.

     8.4.4  Measurement of area.  The area of the sample peak is
            measured by an electronic integrator or some other
            suitable form of area measurement, and preliminary results
            are read from a standard curve prepared as discussed below.

8.5  Determination of Desorption Efficiency

     8.5.1  Importance of determination.  The desorption efficiency of
            a particular compound can vary from one laboratory to
            another and also from one batch of charcoal tc another.
            Thus,  it is necessary to determine at least once the
            percentage of vinyl chloride that is removed in the
                                  31

-------
                desorption process.  Desorption efficiency should be
                determined on the same batch of charcoal tubes used in
                sampling.  Results indicate that desorption efficiency
                varies with loading (total vinyl chloride on the tube),
                particularly at lower values, i.e., 2.5 Mg.

         8.5.2  Procedure for determining desorption efficiency.  Charcoal
                tubes from the same batch as that used in obtaining samples
                are used in this determination.  A measured volume of vinyl
                chloride gas is injected into a bag containing a measured
                volume of air.  The bag is made of Tedlar (or a material
                which will retain the vinyl chloride and not absorb it)
                and should have a gas sampling valve and a septum injection
                port.  The concentration of the bag may be calculated
                knowing room temperature and pressure.  A measured volume
                is then sampled through a charcoal tube with a calibrated
                sampling pump.  At least five tubes are prepared in this
                manner.  These tubes are desorbed and analyzed in the same
                manner as the samples (See Section 8.4).  Samples taken
                with a gas tight syringe from the bag are also injected
                into the GC.  The concentration in the bag is compared to
                the concentration obtained from the tubes.

                The desorption efficiency equals the amount of vinyl
                chloride desorbed from the charcoal divided by the quantity
                of vinyl chloride contained in the volume of synthetic
                atmosphere sampled, or

                    	quantity vinyl chloride from charcoal	
                    concentration vinyl chloride .. volume atmosphere
                           in atmosphere                sampled

9.  Calibration and Standards

    CAUTION:  Laboratory Operations Involving Carcinogens

              Vinyl chloride has been identified as a human carcinogen
              and appropriate precautions must be taken in handling this
              gas.  The Occupational Safety and Health Administration
              has promulgated regulations for the use and handling of
              vinyl chloride.  They may be found in 29 CFR 1910.93q
              (Section 1910.93q in Title 29 of the Code of Federal
              Regulations available in the Federal Register, Vol. 39,'
              No. 194, Friday, October 4, 1974, pp. 35890-35898).

    A series of standards, varying in concentration over the range of
    interest, are prepared and analyzed under the same GC conditions and
    during the same time period as the unknown samples.  Curves are
    established by plotting concentration in jig/1.0 mH versus peak area.
    There are two methods of preparing standards and as long as highly
    purified vinyl chloride is used, both are comparable.
                                     32

-------
     NOTE:  Since no internal standard is used in the method, standard
     solutions must be analyzed at the same time that the sample analysis
     is done.  This will minimize the effect of day-to-day variations of
     the FID response.

     9.1  Standard Preparation

          Gravimetric Method - Vinyl chloride is slowly bubbled into a
          tared 10-ml volumetric flask containing approximately 5 ml
          of toluene.  After 3 minutes, the flask is again weighed.  A
          weight change of 100-300 mg is usually observed.  The solution
          is diluted to exactly 10 ml with carbon disulfide and is used
          to prepare other standards by removal of aliquots with different
          sized syringes.  Subsequent dilution of these aliquots with
          carbon disulfide results in a series of points that are linear
          from the range of 0.2 nanograms per injection, the minimum
          detectable amount of vinyl chloride, to 1.5 micrograms per
          injection.

          Volumetric Method - A 1-ml gas sample of pure vinyl chloride
          is drawn into a gas-tight syringe and the tip of the needle is
          inserted into a 10-ml volumetric flask containing approximately
          5 ml of CS2 •  The plunger is withdrawn slightly to allow the
          CS2 to enter the syringe.  The action of the vinyl chloride
          dissolving in the CS2 creates a vacuum and the syringe becomes
          filled with the solvent.  An air bubble (~2%) is present and
          was found to be due to the void volume in the needle of the
          syringe.  The solution is returned to the flask and the
          syringe is rinsed with clean CS2 and the washings added to
          the volumetric.  The volumetric is then filled to the mark
          with CS2-  Other standards are then prepared from this stock
          solution.

          Standards are stored in a freezer at -20°C and are found to
          be stable at this temperature for three days.  Tight-fitting
          plastic tops on the volumetrics seem to retain the vinyl
          chloride better than ground glass stoppers.

10.  Calculations

     10.1 The weight, in yg, correspondong to each peak area is read from
          the standard curve for vinyl chloride.  No volume corrections
          are needed, because the standard curve is based on yg/1.0 mfc
          CS2 and the volume of sample injected is identical to the
          volume of the standards injected.

     10.2 Corrections for the blank are made for each sample.

                             Vg -•-- Mgs -
          where :
                ygs = yg found in front section of sample tube
                yg  = yg found in front section of blank tube

          A similar procedure is followed for the backup sections.
                                    33

-------
    10.3  These values are further corrected for the desorption efficiency
          at the level of vinyl chloride measured.
                                   UB
          Corrected Pg =  -, - '——. — 6 ee.  .
                          desorption efficiency
    10.4  The corrected amounts present in the front and backup sections
          of the same sample tube are added to determine the total amount
          of vinyl chloride in the sample.

    10.5  The concentration of the vinyl chloride in the air sampled is
          expressed in mg/nr*, which is numerically equal to yg/liter of
          air
              , 3      ,.     total yg  (Section 10.4)
           mg/nr> = pg/X, =   - a-^ - -

          where :
                 V is the volume of air sampled

    10.6  Another method of expressing concentration is ppm, defined as
          y£ of vinyl chloride gas/liter of air

                              /»     v 24.45 ... 760   T+273
                     ppm=  yp/*     X      ~ * ~~ X
          where :
                P = pressure  (mm Hg) of air sampled
                T = temperature (°C) of air sampled
            24.45 = molar volume (£ /mole) at 25°C and 760 mm Hg
            62.5  = molecular weight (g/mole) of vinyl chloride
              760 = standard pressure  (mm Hg)
              298 = standard temperature (°K)

11. References

    11.1  Hill, R.H. , C.S. McCammon, A.T. Saalwaechter , A.W. Teass, and
          W.J. Woodfin, "Determination of Vinyl Chloride in Air," in
          preparation.

    11.2  White, L.D., D.G. Taylor, P. A. Mauer, and R.E. Kupel, "A
          Convenient Optimized Method  for the Analysis of Selected
          Solvent Vapors in the Industrial Atmosphere," Am. Ind. Hyg.
          Assn. J., 31, 225 (1970).
                                     34

-------
                                TECHNICAL REPORT DATA
                         (Please read Inzlructions on the reverse before completing)
 1. REPORT NO.
  EPA-600/2-76-124
                                                     3. RECIPIENT'S ACCESSION-NO.
 4. TITLE AND SUBTITLE
 Sampling of Automobile Interiors for Vinyl
  Chloride Monomer
            5. REPORT DATE
             Mav 1976
            6. PERFORMING ORGANIZATION CODE
 7. AUTHOR(S)
    William H. Hedley,  Joseph T.  Cheng,
    Robert J. McCormick, and Woodrow A. Lewis
            8. PERFORMING ORGANIZATION REPORT NO.

               MRC-DA-535
 9. PERFORMING ORGANIZATION NAME AND ADDRESS
 Monsanto Research Corporation
 1515 Nicholas Road
 Dayton, Ohio 45407
            10. PROGRAM ELEMENT NO.
            1AB015; ROAP 21AXM-073
            11. CONTRACT/GRANT NO.
            68-02-1404
            Task 1, Change 2
 12. SPONSORING AGENCY NAME AND ADDRESS
 EPA, Office of Research and Development
 Industrial Environmental Research Laboratory
 Research Triangle Park, NC  27711
            13. TYPE OF REPORT AND PERIOD COVERED
            Task final; 6-9/75	
            14. SPONSORING AGENCY CODE
             EPA-ORD
 15. SUPPLEMENTARY NOTESIERL-RTP project officer for this
 Mail Drop 62,  Ext 2547.
          report is David K. Oestreich,
 16. ABSTRACT
       The report  gives results of a study to qualitatively identify
 organic pollutants in the  air inside new automobiles.     In recent
 years,  concern has developed over the  concentration  of organic
 vapors  inside new automobiles.,   A literature search first identi-
 fied numerous volatilization products  from plastics  used in the
 construction of  automobile interiors.   Charcoal tubes  were used  to
 collect air samples in seven test vehicles.  Vinyl chloride mono-
 mer  concentrations of 0.4  to  1.2 ppm  were detected  in two vehicles,
 The  concentrations in the  other five test vehicles during this
 preliminary study were below the detection limit of  0.05 ppm.
                            KEY WORDS AND DOCUMENT ANALYSIS
                DESCRIPTORS
                                         b.IDENTIFIERS/OPEN ENDED TERMS
                        c.  COSATI Field/Group
 Air Pollution
 Automobiles
 Vinyl Chloride
 Organic Compounds
 Plastics
 Vaporizing
Air Pollution Control
Automobile Interiors
Vinyl Chloride Monomer
13B
13F
07C

111
07D
 8. DISTRIBUTION STATEMENT

 Unlimited
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
   39
20. SECURITY CLASS (This page)
Unclassified
                        22. PRICE
EPA Form 2220-1 (9-73)
                                        35

-------