ASTM D5932-08(2013)
(Test Method)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
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
SIGNIFICANCE AND USE
5.1 TDI is used mostly in the preparation of rigid and semi-rigid foams and adhesives.
5.2 Isocyanate use has been growing for the last 20 years and the industrial need is still growing.
5.3 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 (6-9).
5.4 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 (10). 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 and 0.005 ppm (V) or 0.036 mg/m3 as a time-weighted average (11).
5.5 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 quantification limit also suits the concentrations often found in the working area.
5.6 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.
5.7 This test method is used to measure gaseous 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.2,3 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).4
1.5 The range of application of this test method, utilizing UV and a fluorescence detector, is validated for 0.029 to 1.16 μg of monomer 2,4- and 2,6-TDI/2.0 mL of desorption solution, which corresponds to concentrations of 0.002 to 0.077 mg/m3 of TDI based on a 15-L air sample. This corresponds to 0.28 to 11 ppb(V) and brackets the established TLV value of 5 ppb(v).
1.6 A field blank sampling system is used to check the possibility of contamination during the entire sampling and analysis.
1.7 The values stated in SI units are to be regarded as the standard.
1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation: D5932 − 08(Reapproved 2013)
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 D5932; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope corresponds to 0.28 to 11 ppb(V) and brackets the established
TLV value of 5 ppb(v).
1.1 This test method covers the determination of gaseous
2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocya- 1.6 A field blank sampling system is used to check the
nate (2,6-TDI) in air samples collected from workplace and possibility of contamination during the entire sampling and
ambient atmospheres. analysis.
1.2 Differential air sampling is performed with a segregat- 1.7 The values stated in SI units are to be regarded as the
2,3
ing device. The gaseous fraction is collected on a glass fiber standard.
filter (GFF) impregnated with 9-(N-methylaminomethyl) an-
1.8 This standard does not purport to address all of the
thracene (MAMA).
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
1.3 The analysis of the gaseous fraction is performed with a
priate safety and health practices and determine the applica-
high performance liquid chromatograph (HPLC) equipped
bility of regulatory limitations prior to use.
with ultraviolet (UV) and fluorescence detectors.
1.4 The analysis of the aerosol fraction is performed sepa-
2. Referenced Documents
rately as described in Ref (1).
2.1 ASTM Standards:
1.5 The range of application of this test method, utilizing
D1193 Specification for Reagent Water
UV and a fluorescence detector, is validated for 0.029 to 1.16
D1356 Terminology Relating to Sampling and Analysis of
µg of monomer 2,4- and 2,6-TDI/2.0 mL of desorption
Atmospheres
solution, which corresponds to concentrations of 0.002 to
D1357 Practice for Planning the Sampling of the Ambient
0.077 mg/m of TDI based on a 15-L air sample. This
Atmosphere
2.2 Other Documents:
Sampling Guide for Air Contaminants in the Workplace
This test method is under the jurisdiction of ASTM Committee D22 on Air
Quality and is the direct responsibility of Subcommittee D22.04 on Workplace Air
3. Terminology
Quality.
Current edition approved April 1, 2013. Published April 2013. Originally
3.1 For definitions of terms used in this test method, refer to
approved in 1996. Last previous edition approved in 2008 as D5932 - 08. DOI:
Terminology D1356.
10.1520/D5932-08R13.
The sampling device for isocyanates is covered by a patent held by Jacques
4. Summary of Test Method
Lesage et al, IRSST, 505 De Maisonneuve Blvd West, Montreal, Quebec, Canada.
Interested parties are invited to submit information regarding the identification of
4.1 A known volume of air is drawn through a segregating
acceptable alternatives to this patented item to the Committee on Standards,ASTM
sampling device.
International Headquarters, 100 Barr Harbor Dr., PO Box C700, West
Conshohocken, PA 19428. Your comments will receive careful consideration at a
4.2 Gaseous and aerosol fraction are sampled simultane-
meeting of the committee responsible, which you may attend. This sampling device
ouslywithatwofilterloadedcassette. Theaerosoliscollected
is currently commercially available under license from SKC Omega Specialty
Division, Eighty-Four, PA.
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 For referenced ASTM standards, visit the ASTM website, www.astm.org, or
this standard. Users of this standard are expressly advised that determination of the contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
validity of any such patent rights, and the risk of infringement of such rights, are Standards volume information, refer to the standard’s Document Summary page on
entirely their own responsibility. the ASTM website.
4 6
The boldface numbers in parentheses refer to the list of references at the end of Available from Institut de Recherche en Santé et en Sécurité du Travail du
this test method. Québec, Laboratory Services and Expertise Department, Montreal, IRSST, 2005.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5932 − 08 (2013)
on the first filter made of polytetrafluoroethylene (PTFE), the allowing isocyanateconcentrationsinbothphysicalstatestobe
gaseous counterpart being adsorbed on the second filter made obtained, thus helping in the selection of ventilation systems
of glass fiber (GFF) impregnated with MAMA. and personal protection.
4.3 The analysis of the monomer and oligomer in the 5.7 This test method is used to measure gaseous concentra-
aerosol fraction is performed separately in accordance with the
tions of 2,4- and 2,6-TDI in air for workplace and ambient
procedure described in Ref (1,2). atmospheres.
4.4 The diisocyanate present as a gas reacts with the
6. Interference
secondary amine function of the MAMA impregnated on the
GFF to form a urea derivative (3,4), as shown below.
6.1 Any substance that can react with MAMA reagent
impregnated on the GFF can affect the sampling efficiency.
This includes strong oxidizing agents.
6.2 Any compound that has the same retention time as the
TDIU derivative and gives the same UV/fluorescence detector
response factor ratio can cause interference. Chromatographic
4.5 Desorption is done with dimethylformamide 67 % con-
taining 33 % mobile phase (70 % acetonitrile, 30 % buffer). conditions can be changed to eliminate an interference.
6.3 A field blank double-filter sampling system is used to
4.6 The resulting solution is analyzed by HPLC with two
detectors in series: UV (254 nm) and fluorescence (254-nm check contamination during the combined sampling,
transportation, and sample storage process.Alaboratory blank
excitation and 412-nm emission) (5).
is used to check contamination occurring during the analytical
4.7 2,4- and 2,6-TDI urea derivatives are separated using
process.
reversed phase HPLC column.
4.8 A complete calibration curve, covering the range of
7. Apparatus
application of the test method, was obtained to determine the
7.1 Sampling Equipment:
linearity of the method (see 1.5).
7.1.1 Personal Sampling Pump, capable of sampling 1.0
4.9 Concentration of urea derivative contained in the
L/min or less for 4 h.
samples is calculated by using an external standard of the
7.1.2 Double Filter Sampling Device, 37 mm in diameter,
appropriate urea derivative.
three-piece personal monitor, plastic holder loaded with a
PTFE filter close to the mouth, followed by a glass fiber filter
5. Significance and Use 2
impregnated with MAMA and a plastic back-up pad. The
5.1 TDI is used mostly in the preparation of rigid and glass fiber filter is impregnated with an amount of MAMA in
semi-rigid foams and adhesives. the range of 0.07 to 0.25 mg.
7.1.3 Flow Measuring Device.
5.2 Isocyanate use has been growing for the last 20 years
and the industrial need is still growing.
7.2 Analytical Equipment:
7.2.1 Liquid Chromatograph, a high-performance liquid
5.3 Diisocyanates and polyisocyanates are irritants to skin,
chromatograph equipped with UV (254-nm wavelength) and
eyes, and mucous membranes. They are recognized to cause
fluorescence detectors (412-nm emission and 254-nm excita-
respiratory allergic sensitization, asthmatic bronchitis, and
tion) and an automatic or manual sample injector.
acute respiratory intoxication (6-9).
7.2.2 Liquid Chromatographic Column, an HPLC stainless
5.4 The American Conference of Governmental Industrial
steel column, capable of separating the urea derivatives. This
Hygienists (ACGIH) has adopted a Threshold Limit Valu-
proposed method recommends a 150- by 4.6-mm internal
e–Time WeightedAverage (TLV—TWA) of 0.036 mg/m with
diameter stainless steel column packed with 0.5-µm C18, or an
a Short-Term Exposure Limit (STEL) of 0.14 mg/m for
equivalent column.
2,4-TDI (10). The Occupational Safety and Health Adminis-
7.2.3 Electronic Integrator, an electronic integrator or any
tration of the U.S. Department of Labor (OSHA) has a
other effective method for determining peak areas.
permissible exposure limit of 0.02 ppm(V) or 0.14 mg/m of
7.2.4 Analytical Balance, an analytical balance capable of
TDI as a ceiling limit and 0.005 ppm (V) or 0.036 mg/m as a
weighing to 0.001 g.
time-weighted average (11).
7.2.5 Microsyringes and Pipets, microsyringes are used in
5.5 Monitoring of respiratory and other problems related to
thepreparationofureaderivativesandstandards.Anautomatic
diisocyanates and polyisocyanates is aided through the utiliza-
pipet, or any equivalent method, is required for sample
tion of this test method, due to its sensitivity and low volume
preparation.
requirements (15 L). Its short sampling times are compatible
7.2.6 pH Meter, a pH meter or any equivalent device
with the duration of many industrial processes and its low
capable of assaying a pH range between 2.5 and 7.
quantification limit also suits the concentrations often found in
7.2.7 Specialized Flasks, three-necked flask and an addi-
the working area.
tional flask for the synthesis of the TDIU standard.
5.6 The segregating sampling device pertaining to this 7.2.8 Magnetic Stirrer, a magnetic stirrer or any other
proposed test method physically separates gas and aerosol equivalent method.
D5932 − 08 (2013)
7.2.9 Glass Jars, 30 mL, and lid, capable of receiving 8.14 2,4-Toluene Diisocyanate 9-(N-Methylaminomethyl)
37-mm filters, used for desorption of samples. Anthracene Derivative (2,4-TDIU).
7.2.10 Reciprocating Shaker, a reciprocating shaker or any 8.14.1 Add 320 µL of 2,4-TDI (8.13) (2 mmoles) to dichlo-
other equivalent device. romethane (8.6) and dilute to 25 mL in a volumetric flask.
7.2.11 Vacuum Filtration System, vacuum filtration system Place the 2,4-TDI solution in an additional flask.
with0.45-µmporositynylonfiltersoranyequivalentmethodto 8.14.2 Dilute approximately 1.3 g (6 mmoles) of 9-(N-
degas the mobile phase.
methylaminomethyl) anthracene (MAMA) (8.9)in50mLof
7.2.12 Syringe Operated Filter Unit, syringes with polyvi- dichloromethane (8.6). Place the MAMA solution in a three-
nylidenefluoride0.22-µmporosityfilterunit,oranyequivalent
necked flask.
method. 8.14.3 Add the TDI (8.13) drop by drop at a temperature of
7.2.13 Injection Vials, 1.5-mL vials with PTFE-coated sep-
25°C to the MAMAsolution (8.14.2), stirring continuously for
tums for injection. 60 to 90 min.
7.2.14 Bottle, amber-colored bottle with cap and PTFE-
8.14.4 Cool the resulting solution on crushed ice.
coated septum for conservation of stock and standard solutions
8.14.5 Filter on a medium speed ashless filter paper or any
of 2,4- and 2,6-TDIU or any equivalent method.
equivalent device.
8.14.6 Dissolvetheprecipitateinhotdichloromethane(8.6).
8. Reagents and Materials
Place in an ice bath to recrystallize and filter as in 8.14.5.
8.1 Purity of Reagents—Reagent grade chemicals shall be 8.14.7 The compound has a melting point of 270°C.
usedinalltests.Allreagentsshallconformtothespecifications
8.14.8 Confirm that the urea derivative with the mass
of the Committee on Analytical Reagents of the American
spectrum, the 2,4-TDI-MAMA has a molecular weight of
Chemical Society where such specifications are available.
610.8 g.
Other grades may be used, provided it is first ascertained that
8.14.9 The conversion factor for TDIU to TDI is 0.2823.
the reagent is of sufficiently high purity to permit its use
8.15 2,6-Toluene Diisocyanate 9-(N-Methylaminomethyl)
without lessening the accuracy of the determination.
Anthracene Derivative (2,6-TDIU)—Same preparation as 2,4-
8.2 Purity of Water—Unlessotherwiseindicated,watershall
TDIU but use 2,6-TDI. The compound starts to show decom-
be reagent water as defined by Type 2 of Specification D1193,
position at 275°C.
HPLC grade.
8.16 Triethylamine—Purity 98 % min.
8.3 Acetonitrile (CH CN)—HPLC grade.
9. Hazards
8.4 Buffer—Place 30 mL of triethylamine (8.16) in water
and dilute to 1 L in a volumetric flask. Add phosphoric acid
9.1 Warning—Diisocyanates are potentially hazardous
(H PO)(8.11) to acidify to pH = 3.0. Filter the buffer under
3 4 chemicals and extremely reactive. Warning on compressed gas
vacuum with a 0.45-µm porosity filter.
cylinders. Refer to MSD sheets for reagents.
8.5 Desorption Solution—Asolvent mixture of dimethylfor-
9.2 Precaution—Avoid exposure to diisocyanate standards.
mamide (8.7) and mobile phase (8.10) in the percentage of 67
Sample and standard preparations should be done in an
and 33 (v/v), respectively.
efficient operating hood. For remedial statement see Ref (13).
8.6 Dichloromethane—Reagent grade.
9.3 Precaution—Avoid skin contact with all solvents and
isocyanates.
8.7 Dimethylformamide—Reagent grade.
8.8 Helium (He)—High purity, 99.999 %. 9.4 Wear safety glasses at all times and other laboratory
protective equipment as necessary.
8.9 9-(N-Methylaminomethyl) Anthracene (MAMA), (F.W.
221.31) 99 % purity.
10. Sampling
8.10 Mobile Phase—A solvent mixture of acetonitrile
10.1 Refer to the Practices D1357 for general information
(CH CN) (8.3) and buffer (8.4) in the percentage of 70 and 30
on sampling.
(v/v), respectively, suitably degassed.
10.2 This proposed test method recommends sampling in
8.11 Phosphoric Acid (H PO )—Reagent grade.
3 4
accordance with the method described in Ref (12,14) of this
8.12 2,4-Toluene Diisocyanate (2,4-TDI)—(F.W. 174.2)
test method.
97 % purity.
10.3 Equip the worker, whose exposure is to be evaluated,
8.13 2,6-Toluene Diisocyanate (2,6-TDI)—(F.W. 174.2)
with a filter holder connected to a belt-supported sampling
97 % purity.
pump. Place the filter, holder pointing downward, in the
breathing zone of the worker. Draw air through the sampling
7 device and collect 15 L at a rate of approximately 1.0 L/min.
Reagent Chemicals, American Chemical Society Specifications , American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
listed by the American Chemical Society, see Analar Standards for Laboratory
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, Whatman No. 40, ashless filter paper has been found satisfactory for this
MD. purpose.
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