ASTM D5932-96(2002)
(Test Method)Standard Test Method for Determination of 2,4-Toluene Diiso cyanate (2,4-TDI) and 2,6-Toluene Diiso cyanate (2,6-TDI) in Air (with 9-(N-Methylaminomethyl) Anthracene Method) (MAMA) in the Workplace
Standard Test Method for Determination of 2,4-Toluene Diiso cyanate (2,4-TDI) and 2,6-Toluene Diiso cyanate (2,6-TDI) in Air (with 9-(N-Methylaminomethyl) Anthracene Method) (MAMA) in the Workplace
SIGNIFICANCE AND USE
TDI is used mostly in the preparation of rigid and semi-rigid foams and adhesives.
Iso—cyanate use has been growing for the last ten years and the industrial need is still growing.
Diisocyanates and polyisocyanates are irritants to skin, eyes, and mucous membranes. They are recognized to cause respiratory allergic sensitization, asthmatic bronchitis, and acute respiratory intoxication (Refs 6-9).
The American Conference of Governmental Industrial Hygienists (ACGIH) has adopted a Threshold Limit Value–Time Weighted Average (TLV—TWA) of 0.036 mg/m3 with a Short-Term Exposure Limit (STEL) of 0.14 mg/m3 for 2,4-TDI (Ref 10). (Ref. ACGIH 1993–4). The Occupational Safety and Health Administration of the U.S. Department of Labor (OSHA) has a permissible exposure limit of 0.02 ppm(V) or 0.14 mg/m3 of TDI as a ceiling limit (11).
Monitoring of respiratory and other problems related to diisocyanates and polyisocyanates is aided through the utilization of this test method, due to its sensitivity and low volume requirements (15 L). Its short sampling times are compatible with the duration of many industrial processes and its low detection limit also suits the concentrations often found in the working area.
The segregating sampling device pertaining to this proposed test method physically separates gas and aerosol allowing isocyanate concentrations in both physical states to be obtained, thus helping in the selection of ventilation systems and personal protection.
This test method is used to measure concentrations of 2,4- and 2,6-TDI in air for workplace and ambient atmospheres.
SCOPE
1.1 This test method covers the determination of gaseous 2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyanate (2,6-TDI) in air samples collected from workplace and ambient atmospheres.
1.2 Differential air sampling is performed with a segregating device., The gaseous fraction is collected on a glass fiber filter (GFF) impregnated with 9-(N-methylaminomethyl) anthracene (MAMA).
1.3 The analysis of the gaseous fraction is performed with a high performance liquid chromatograph (HPLC) equipped with ultraviolet (UV) and fluorescence detectors.
1.4 The analysis of the aerosol fraction is performed separately as described in Ref ().
1.5 The range of application of this test method, utilizing UV and a fluorescence detector, is validated for 0.02 to 4.2 g of monomer 2,4- and 2,6-TDI/2.0 mL of desorption solution, which corresponds to concentrations of 0.001 to 0.28 mg/m3 of TDI based on a 15-L air sample. This corresponds to 0.15 to 40 ppb(V) and brackets the established TLV value of 5 ppb(v).
1.6 The average correlation coefficient is 0.9999 and 0.9999 for the UV detector, for 2,6 and 2,4-TDI, respectively. For the fluorescence detector, the average correlation coefficient is 0.9803 and 0.9999 for 2,6 and 2,4-TDI, respectively. These values were obtained from seven standard solutions distributed along the calibration curve, each standard being injected six times, with the curve having been done twice by different operators.
1.7 The quantification limit for 2,6-TDI monomers is 0.007 μg/2 mL of desorption solution, which corresponds to 0.0005 mg/m 3 for 15-L sampled air volume for the UV detector. For the fluorescence detector, the quantification limit is 0.003 μg/2 mL of desorption solution, which correspond to 0.0002 mg/m3 for a volume of 15 L collected in air. These values are equal to ten times the standard deviation obtained from ten measurements carried out on a standard solution whose concentration of 0.02 μg/2 mL is close to the expected detection limit.
1.8 The quantification limit for 2,4-TDI monomers is 0.015 μg/2 mL of desorption solution, which corresponds to 0.001 mg/m 3 for 15-L sampled air volume for the UV detector. For the fluorescence detector, the quantification limit is 0.012 μg/2 mL of desorption solution, which corresponds to 0.0008 mg/m3 for a volume of 15 L of collected air. The...
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Designation:D5932–96 (Reapproved 2002)
Standard Test Method for
Determination of 2,4-Toluene Diisocyanate (2,4-TDI) and 2,6-
Toluene Diisocyanate (2,6-TDI) in Air (with 9-(N-
Methylaminomethyl) Anthracene Method) (MAMA) in the
Workplace
This standard is issued under the fixed designation D 5932; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope TDI based on a 15-Lair sample.This corresponds to 0.15 to 40
ppb(V) and brackets the established TLV value of 5 ppb(v).
1.1 This test method covers the determination of gaseous
1.6 The average correlation coefficient is 0.9999 and 0.9999
2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyan-
for the UV detector, for 2,6 and 2,4-TDI, respectively. For the
ate (2,6-TDI) in air samples collected from workplace and
fluorescence detector, the average correlation coefficient is
ambient atmospheres.
0.9803 and 0.9999 for 2,6 and 2,4-TDI, respectively. These
1.2 Differential air sampling is performed with a segregat-
2,3
values were obtained from seven standard solutions distributed
ing device. The gaseous fraction is collected on a glass fiber
along the calibration curve, each standard being injected six
filter (GFF) impregnated with 9-(N-methylaminomethyl) an-
times, with the curve having been done twice by different
thracene (MAMA).
operators.
1.3 The analysis of the gaseous fraction is performed with a
1.7 The quantification limit for 2,6-TDI monomers is 0.007
high performance liquid chromatograph (HPLC) equipped
µg/2 mL of desorption solution, which corresponds to 0.0005
with ultraviolet (UV) and fluorescence detectors.
mg/m for 15-L sampled air volume for the UV detector. For
1.4 The analysis of the aerosol fraction is performed sepa-
the fluorescence detector, the quantification limit is 0.003 µg/2
rately as described in Ref (1).
mLof desorption solution, which correspond to 0.0002 mg/m
1.5 The range of application of this test method, utilizing
for a volume of 15 Lcollected in air. These values are equal to
UV and a fluorescence detector, is validated for 0.02 to 4.2 µg
ten times the standard deviation obtained from ten measure-
of monomer 2,4- and 2,6-TDI/2.0 mL of desorption solution,
ments carried out on a standard solution whose concentration
which corresponds to concentrations of 0.001 to 0.28 mg/m of
of 0.02 µg/2 mL is close to the expected detection limit.
1.8 The quantification limit for 2,4-TDI monomers is 0.015
This test method is under the jurisdiction of ASTM Committee D22 on µg/2 mL of desorption solution, which corresponds to 0.001
Sampling and Analysis of Atmospheres and is the direct responsibility of Subcom-
mg/m for 15-L sampled air volume for the UV detector. For
mittee D22.04 on Workplace Atmospheres.
the fluorescence detector, the quantification limit is 0.012 µg/2
Current edition approved April 10, 1996. Published June 1996.
mLofdesorptionsolution,whichcorrespondsto0.0008mg/m
The sampling device for isocyanates is covered by a patent held by Jacques
Lesage et al, IRSST, 505 De Maisonneuve Blvd West, Montreal, Quebec, Canada.
for a volume of 15 Lof collected air. These values are equal to
Interested parties are invited to submit information regarding the identification of
ten times the standard deviation obtained from ten measure-
acceptable alternatives to this patented item to the Committee on Standards,ASTM
ments carried out on a standard solution whose concentration
International Headquarters, 100 Barr Harbor Dr., PO Box C700, West Consho-
hocken, PA 19428. Your comments will receive careful consideration at a meeting 0.02 µg/2 mL is close to the expected detection limit.
of the committee responsible, which you may attend. This sampling device is
1.9 2,4- and 2,6-TDI isomers can be separated using a
currently commercially available under license from Omega Specialty Instrument,
reversed phase C18 column for HPLC. The UV and fluores-
Chelmsford, MA.
cence detector response factor (RF) ratio characterize each
The American Society for Testing and Materials takes no position respecting
the validity of any patent rights asserted in connection with any item mentioned in
isomer.
this standard. Users of this standard are expressly advised that determination of the
1.10 A field blank sampling system is used to check the
validity of any such patent rights, and the risk of infringement of such rights, are
possibility of contamination during the entire analytical pro-
entirely their own responsibility.
cess.
The boldface numbers in parentheses refer to the list of references at the end of
this test method.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D5932–96 (2002)
1.11 The values stated in SI units are to be regarded as the 4.9 A complete calibration curve, covering the range of
standard. application of the test method, was obtained to determine the
1.12 This standard does not purport to address all of the linearity of the method (see 1.5).
safety concerns, if any, associated with its use. It is the 4.10 The amount of urea derivatives in the samples is
responsibility of the user of this standard to establish appro- calculated from the response factor and the area obtained for
priate safety and health practices and determine the applica- the sample peaks.
bility of regulatory limitations prior to use. 4.11 The amount of diisocyanates is calculated from the
amount of urea derivatives determined in the sample.
2. Referenced Documents
2.1 ASTM Standards: 5. Significance and Use
D 1193 Specification for Reagent Water
5.1 TDI is used mostly in the preparation of rigid and
D 1356 Terminology Relating to Sampling and Analysis of
semi-rigid foams and adhesives.
Atmospheres
5.2 Iso—cyanate use has been growing for the last ten years
D 1357 Practice for Planning the Sampling of the Ambient
and the industrial need is still growing.
Atmosphere
5.3 Diisocyanates and polyisocyanates are irritants to skin,
2.2 Other Documents:
eyes, and mucous membranes. They are recognized to cause
Sampling Guide for Air Contaminants in the Workplace
respiratory allergic sensitization, asthmatic bronchitis, and
acute respiratory intoxication (Refs 6-9).
3. Terminology
5.4 The American Conference of Governmental Industrial
3.1 For definitions of terms used in this test method, refer to
Hygienists (ACGIH) has adopted a Threshold Limit Value-
Terminology D 1356.
–Time Weighted Average (TLV—TWA) of 0.036 mg/m with
a Short-Term Exposure Limit (STEL) of 0.14 mg/m for
4. Summary of Test Method
2,4-TDI (Ref 10). (Ref. ACGIH 1993–4). The Occupational
4.1 A known volume of air is drawn through a segregating
Safety and Health Administration of the U.S. Department of
sampling device.
Labor (OSHA) has a permissible exposure limit of 0.02
4.2 Gaseous and aerosol fraction are sampled simulta-
ppm(V) or 0.14 mg/m of TDI as a ceiling limit (11).
neously with a two filter loaded cassette. The aerosol is
5.5 Monitoring of respiratory and other problems related to
collected on the first filter made of polytetrafluoroethylene
diisocyanates and polyisocyanates is aided through the utiliza-
(PTFE), the gaseous counterpart being adsorbed on the second
tion of this test method, due to its sensitivity and low volume
filter made of glass fiber (GFF) impregnated with MAMA.
requirements (15 L). Its short sampling times are compatible
4.3 The analysis of the monomer and oligomer in the
with the duration of many industrial processes and its low
aerosol fraction is performed separately according to the
detection limit also suits the concentrations often found in the
procedure described in Ref (1,2).
working area.
4.4 The diisocyanate present as a gas reacts with the
5.6 The segregating sampling device pertaining to this
secondary amine function of the MAMA impregnated on the
proposed test method physically separates gas and aerosol
GFF to form a urea derivative (3,4).
allowing isocyanateconcentrationsinbothphysicalstatestobe
obtained, thus helping in the selection of ventilation systems
and personal protection.
5.7 This test method is used to measure concentrations of
2,4- and 2,6-TDI in air for workplace and ambient atmo-
spheres.
4.5 Desorption is done with dimethylformamide 67 % con-
6. Interference
taining 33 % mobile phase (70 % acetonitrile, 30 % buffer).
6.1 Any substance that can react with MAMA reagent
4.6 The resulting solution is analyzed by HPLC with two
impregnated on the GFF can affect the sampling efficiency.
detectors in series: UV (254 nm) and fluorescence (254-nm
This includes strong oxidizing agents.
excitation and 412-nm emission) Ref (5).
6.2 Any compound that has the same retention time as the
4.7 2,4- and 2,6-TDI urea derivatives are separated using
TDIU derivative and gives the same UV/fluorescence detector
reversed phase HPLC column.
response factor ratio can cause interference. Chromatographic
4.8 The response factor is determined by the ratio of the
conditions can be changed to eliminate an interference.
concentration of the calibration solution and the area of the
6.3 A field blank double-filter sampling system is used to
peak obtained.
check contamination during the combined sampling, transpor-
tation, and sample storage process. A laboratory blank is used
to check contamination occurring during laboratory manipula-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
tions.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
7. Apparatus
Available from Institut de Recherche en Santé et en Sécurité du Travail du
Québec, Laboratory Division, Montreal, IRSST, 1995. 7.1 Sampling Equipment:
D5932–96 (2002)
7.1.1 Personal Sampling Pump, capable of sampling 1.0 Chemical Society where such specifications are available.
L/min or less for 4 h. Other grades may be used, provided it is first ascertained that
the reagent is of sufficiently high purity to permit its use
7.1.2 Double Filter Sampling Device, 37 mL in diameter,
without lessening the accuracy of the determination.
three-piece personal monitor, plastic holder loaded with a
8.2 Purity of Water—Unless otherwise indicated, water
PTFE filter close to the mouth, followed by a glass fiber filter
shall be reagent water as defined by Type 2 of Specification
impregnated with MAMA and a plastic back-up pad. The
D 1193, HPLC grade.
glass fiber filter is impregnated with an amount of MAMA in
8.3 Acetonitrile (CH CN)—HPLC grade.
the range of 0.07 to 0.25 mg.
8.4 Buffer—Place 30 mL of triethylamine (8.16) in water
7.1.3 Flow Measuring Device.
and dilute to 1 L in a volumetric flask. Add phosphoric acid
7.2 Analytical Equipment: (H PO)(8.11) to acidify to pH = 3.0. Filter the buffer under
3 4
vacuum with a 0.45-µm porosity filter.
7.2.1 Liquid Chromatograph, a high-performance liquid
8.5 Desorption Solution—Asolventmixtureofdimethylfor-
chromatograph equipped with UV (254-nm wavelength) and
mamide (8.7) and mobile phase (8.10) in the percentage of 67
fluorescence detectors (412-nm emission and 254-nm excita-
and 33 (v/v), respectively.
tion) and an automatic or manual sample injector.
8.6 Dichloromethane—Reagent grade.
7.2.2 Liquid Chromatographic Column, an HPLC stainless
8.7 Dimethylformamide—Reagent grade.
steel column, capable of separating the urea derivatives. This
8.8 Helium (He)—“High purity.”
proposed method recommends a 150- by 4.6-mm internal
8.9 9-(N-Methylaminomethyl) Anthracene (MAMA), (F.W.
diameter stainless steel column packed with 0.5-µm C18, or an
221.31) 99 % purity.
equivalent column.
8.10 Mobile Phase—A solvent mixture of acetonitrile
(CH CN) (8.3) and buffer (8.4) in the percentage of 70 and 30
7.2.3 Electronic Integrator, an electronic integrator or any
(v/v), respectively, suitably degassed.
other effective method for determining peak areas.
8.11 Phosphoric Acid (H PO )—Reagent grade.
3 4
7.2.4 Analytical Balance, an analytical balance capable of
8.12 2,4-Toluene Diisocyanate (2,4-TDI)—(F.W. 174.2)
weighing to 0.001 g.
97 % purity.
7.2.5 Microsyringes and Pipets, microsyringes are used in
8.13 2,6-Toluene Diisocyanate (2,6-TDI)—(F.W. 174.2)
thepreparationofureaderivativesandstandards.Anautomatic
97 % purity.
pipet, or any equivalent method, is required for sample
8.14 2,4-Toluene Diisocyanate 9-(N-Methylaminomethyl)
preparation.
Anthracene Derivative (2,4-TDIU).
7.2.6 pH Meter, a pH meter or any equivalent device
8.14.1 Add 320 µL of 2,4-TDI (8.13) (2 mmoles) to dichlo-
capable of assaying a pH range between 2.5 and 7. romethane (8.6) and dilute to 25 mL in a volumetric flask.
Place the 2,4-TDI solution in an additional flask.
7.2.7 Specialized Flasks, three-necked flask and an addi-
8.14.2 Dilute approximately 1.3 g (6 mmoles) of 9-(N-
tional flask for the synthesis of the TDIU standard.
methylaminomethyl) anthracene (MAMA) (8.9)in50mLof
7.2.8 Magnetic Stirrer, a magnetic stirrer or any other
dichloromethane (8.6). Place the MAMA solution in a three-
equivalent method.
necked flask.
7.2.9 Ointment Jars, 30 mL, ointment jars and lid, capable
8.14.3 Add the TDI (8.13) drop by drop at a temperature of
of receiving 37-mm filters, used for desorption of samples.
25°C to the MAMAsolution (8.14.2), stirring continuously for
7.2.10 Reciprocating Shaker, a reciprocating shaker or any 60 to 90 min.
8.14.4 Cool the resulting solution on crushed ice.
other equivalent device.
8.14.5 Filter on a medium speed ashless filter paper or any
7.2.11 Vacuum Filtration System, vacuum filtration system
equivalent device.
with0.45-µmporositynylonfiltersoranyequivalentmethodto
8.14.6 Dissolvetheprecipitateinhotdichloromethane(8.6).
degas the mobile phase.
Place in an ice bath to recrystallize and filter as in 8.14.5.
7.2.12 Syringe Operated Filter Unit, syringes with polyvi-
8.14.7 The compound has a melting point of 270°C.
nylidenefluoride0.45-µmporosityfilterunit,oranyequivalent
8.14.8 Confirm that the urea derivative with the mass
method.
spectrum, the 2,4-TDI-MAMA has a molecular weight of
7.2.13 Injection Vials, 1.5-mL vials with PTFE-coated sep-
610.8 g.
tums for injection.
8.14.9 The conversion factor for TDIU to TDI is 0.2823.
7.2.14 Bottle, amber-colored bottle with cap and PTFE-
coated septum for conservation of stock and standard solutions
of 2,4- and 2,6-TDIU or any equivalent method.
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestio
...
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