ISO/TC 146/SC 2/WG 4 - Organic vapours

The method described in this document quantifies the absolute exposure to mineral oil vapours and droplets, within a concentration range from 0,5 mg/m3 to 125 mg/m3, in the inhalable fraction of the workplace air. This document contains comprehensive information and instructions on the equipment and chemicals to be used. This method is applicable for water soluble oils and metal working fluids.

This document specifies a method for the sampling and analysis of airborne organic isocyanates in workplace air. This document is applicable to a wide range of organic compounds containing isocyanate groups, including monofunctional isocyanates (e.g. phenyl isocyanate), diisocyanate monomers [e.g. 1,6-hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate (MDI), and isophorone diisocyanate (IPDI)], prepolymers (e.g. the biuret and isocyanurate of HDI), as well as chromatographable intermediate products formed during production or thermal breakdown of polyurethane. In mixed systems of HDI and IPDI products, it is impossible to identify and quantify low levels of IPDI monomer using this document, due to coelution of IPDI monomer with HDI-uretidinedione. It is known that the method underestimates the oligomer in MDI-based products. Total isocyanate group (NCO) is underestimated in MDI-based products by about 35 % as compared to dibutylamine titration. The method has been successfully modified to be used with LC-MS-MS for TDI monomer using an isocratic 70 % acetonitrile/30 % 10 mM ammonium formate mobile phase. The useful range of the method, expressed in moles of isocyanate group per species per sample, is approximately 1 × 10−10 to 2 × 10−7. The instrumental detection limit for the monomers using both ultraviolet (UV) detection and fluorescence (FL) detection is about 2 ng monomer per sample. The useful limit of detection for the method using reagent impregnated filters is about 10 ng to 20 ng monomer per sample for both UV and FL detection. For a 15 l sample, this corresponds to 0,7 µg/m−3 to 1,4 µg/m−3. For impinger samples, which require solid phase extraction, experience has shown that the useful limit of detection is about 30 ng to 80 ng monomer per sample.

ISO 17734-1:2013 gives general guidance for the sampling and analysis of airborne isocyanates in workplace air. When amines and aminoisocyanates are suspected to be emitted (e.g. from thermal degradation of PUR), it is recommended that, in addition to isocyanates, the amines and aminoisocyanates in the air are determined, using DBA and ethyl chloroformate as reagents (see ISO 17734-2). The method is suitable for the determination of a wide range of different isocyanates in both the gas and particle phases. Typical monofunctional isocyanates that can be determined are isocyanic acid (ICA), methyl isocyanate (MIC), ethyl isocyanate (EIC), propyl isocyanate (PIC), butyl isocyanate (BIC), and phenyl isocyanate (PhI). Typical monomeric diisocyanates include 1,6-hexamethylene diisocyanate (HDI), 2,4- and 2,6-toluene diisocyanate (TDI), 4,4'-methylenediphenyl diisocyanate (MDI), 1,5-naphthyl diisocyanate (NDI), isophorone diisocyanate (IPDI), and 4,4'-dicyclohexylmethane diisocyanate (HMDI). Multifunctional isocyanates that can be determined are typically oligomers in polymeric MDI, biuret-, isocyanurate-, and allophanate-adducts, and prepolymeric forms of isocyanates. The instrumental detection limit for aliphatic isocyanates is about 5 nmol/sample and for aromatic isocyanates, it is about 0,2 nmol/sample. For a 15 l air sample, this corresponds to 0,6 ng∙m?3 for HDI and 0,02 ng∙m?3 for TDI. The useful range, for a 5 l air sample, of the method is approximately 0,001 µg∙m?3 to 200 mg∙m?3 for TDI.

ISO 17734-2:2013 gives general guidance for the sampling and analysis of airborne amines and aminoisocyanates in workplace air. It is strongly recommended that the determination of amines and aminoisocyanates is made together with the determination of isocyanates in air, using DBA as a reagent (see ISO 17734-1). The method can be used for simultaneous determinations of amines, such as 4,4'-methylenediphenyldiamine (4,4'-MDA), 2,4- and 2,6-toluenediamine (2,4- and 2,6-TDA), and 1,6-hexamethylenediamine (1,6-HDA), and compounds containing both isocyanate and amine groups, such as 4,4'-methylenediphenyl aminoisocyanate (4,4'-MAI), 2,4-, 4,2-, and 2,6-toluene aminoisocyanate (2,4-, 4,2-, and 2,6-TAI), and 1,6-hexamethylene aminoisocyanate (1,6-HAI). The method is suitable for collecting amines and aminoisocyanates in both the gas and particle phases. The instrumental detection limit for the amines is about 5 nmol/sample and for the aminoisocyanate, it is about 0,3 nmol/sample. For a 15 l air sample, this corresponds to 0,4 ng⋅m?3 for TDA and 0,03 ng⋅m?3 for TAI.

This International Standard gives general guidance for the sampling and analysis of airborne toluene diisocyanate (TDI) in workplace atmospheres. The procedure specified in this International Standard is especially suitable for short (15 min) and long-term (4 h) sampling and analysis of 2,4- and 2,6-TDI vapours. The upper limit for this method is approximately 85 µg of TDI per sample. This is a conservative upper limit based on the requirement of maintaining a sufficient amount of reagent on the coated glass fibre filter while permitting a 4 h sample to be collected at 1 l/min from an atmosphere containing 50 nl/l of TDI. The quantitation limits for this method are 0,039 µg for 2,4-TDI and 0,034 μg for 2,6-TDI using a fluorescence detector. These limits, for a 15-min sample collected at 1 l/min, are equivalent to 0,36 nl/l for 2,4-TDI, and 0,32 nl/l for 2,6-TDI. For a 4 h sample collected at 1 l/min, the limits are equivalent to 0,022 nl/l for 2,4-TDI and 0,020 nl/l for 2,6-TDI. The commercial availability of the specified reagents, the use of common analytical instrumentation, and the current widespread use of the method make this standard method ideally suited for the determination of TDI in workplace environments.

ISO/TR 17737 provides industrial hygienists, employers and workers with a broad overview of isocyanates, their uses in industry, methods of measurement and guidance on choosing the appropriate sampling strategy. While not all issues can be addressed here in detail, ISO/TR 17737 discusses areas of concern to alert the industrial hygienist, employer and worker involved with the use of isocyanates to the importance of sampling and the key issues involved in choosing a sampling strategy for their workplace, and directs them to seek further information on the topic(s) of concern.

ISO 17736:2010 gives general guidelines for the sampling and analysis of airborne isocyanates in workplace air. ISO 17736:2010 is appropriate for organic compounds containing free isocyanate functional groups and is specific for the quantification of monomers, polymers and prepolymers, vapours and aerosols. Differential air sampling is performed with a segregating device which can show the physical state of the isocyanates analysed as found in the field. This capacity, however, may show limitations for given situations, e.g. when aerosols collected on the first filter contain free monomer that migrates to the second filter and is then quantified as vapour phase isocyanate. The determination of aromatic monomers includes toluene diisocyanate (TDI) and 4,4'-diisocyanato-diphenylmethane (MDI). Aliphatic monomers include isophorone diisocyanate (IPDI), 4,4'-methylene bis-(cyclohexyl isocyanate) (HMDI) and 1,6-hexamethylene diisocyanate (HDI). Isocyanate oligomers and prepolymers can also be determined using this method. The double-filter method is designed to determine short-term (15 min) exposure concentrations of organic isocyanates in a workplace environment by personal monitoring or by fixed location monitoring. However, if the exposure is expected to be in vapour form only, then sampling time can be extended to 8 h. Since the filter is derivatized in the field immediately after sampling, loss of isocyanate aerosol because of its reaction with other chemicals is negligible except for very fast-reacting isocyanate systems such as foam spraying of MDI in polyurethane applications. The method is suitable for the measurement of airborne organic isocyanates in the NCO equivalent concentration range of 0,01 µg/sample to 2,1 µg/sample, corresponding to approximately 0,67 µg/m3 to 140 µg/m3 for a 15 l sample volume. This range brackets about eight times the current established threshold limit value (TLV) of 5 ppb for monomers set by many national authorities.

ISO 16702:2007 gives general guidance for the sampling and analysis of airborne organic isocyanate (NCO) compounds in workplace air. ISO 16702:2007 is appropriate for a wide range of organic compounds containing isocyanate functional groups, including isocyanate monomers and prepolymers. Monomers containing a single isocyanate moiety (e.g. methyl isocyanate, ethyl isocyanate, phenyl isocyanate, hexyl isocyanate) are produced during thermal degradation of polyurethanes, i.e. flame bonding and laser cutting. Isocyanate polymers, also called polyisocyanates, homopolymers, oligomers or prepolymers, are derived from the diisocyanate monomers by self-condensation or reaction with polyols. Polymeric diisocyanates are widely used in the polyurethanes, paints and coatings, and adhesives industries. ISO 16702:2007 is appropriate for measuring any product containing free isocyanate groups. It was developed primarily for the commonly used methylenebis(phenylisocyanate) (MDI), 1,6-(diisocyanato)hexane (HDI), and toluene diisocyanate (TDI) and their oligomers and polymers. It has also been used for isophorone diisocyanate (IPDI), hydrogenated methylenebis(phenylisocyanate) (HMDI), and naphthyldiisocyanate (NDI), and their oligomers and polymers. The method is used to determine time-weighted average concentrations of organic isocyanates in workplace atmospheres, and is suitable for sampling over periods in the range 0,5 min to 8 h. The method is designed for personal monitoring, but can also be used for fixed location monitoring by suitable modification. The method is suitable for the measurement of airborne organic isocyanates in the concentration range from approximately 0,1 µg/m3 to 140 µg/m3 for a 15 l sample volume.

ISO 16107:2007 specifies methods for evaluation of sampler performance in terms of workplace conditions: wind speed, humidity, temperature, atmospheric pressure, and analyte variation. The concise set of experiments specified aims to minimize cost to the user. The evaluation is limited to conditions commonly encountered in personal sampling in the indoor workplace setting, namely wind speeds of up to 0,5 m/s and for sampling periods typically from 2 h to 8 h. Static or area sampling, unlike personal sampling where movement of the subject is significant, may sometimes be subject to sampling-rate reduction due to stagnation at very low wind speeds. ISO 16107:2007 therefore does not apply to wind speeds of less than 0,1 m/s relative to static samplers. Samplers are also tested for compliance with the manufacturer's stated limits on capacity, possibly in the presence of interfering compounds. Given a suitable exposure chamber, the sampler evaluation protocol can be extended to cover sampler use for other sampling periods and conditions. ISO 16107:2007 indicates how to measure diffusive sampler uncertainty for characterizing concentration estimates obtained subsequent to the evaluation. It is impractical continually to re-evaluate diffusive sampler performance under various environmental conditions prevailing during application.

This part of ISO 16200 gives general guidance for the sampling and analysis of volatile organic compounds (VOCs) in air. This part of ISO 16200 is applicable to a wide range of VOCs, including hydrocarbons, halogenated hydrocarbons, esters, glycol ethers, ketones and alcohols. A number of devices and sorbents are recommended for the sampling of these VOCs, each sorbent having a different range of applicability. NOTE Activated coconut shell charcoal is frequently used. Very polar compounds may require derivatization; very low boiling compounds will only be partially retained by the sorbents and can only be estimated qualitatively. Semi-volatile compounds will be fully retained by the sorbents, but may only be partially recovered. This part of ISO 16200 is valid for the measurement of airborne vapours of VOCs in a concentration range of approximately 1 mg/m3 to 1000 mg/m3 individual organic for an exposure time of 8 h. The upper limit of the useful range is set by the sorptive capacity of the sorbent used and, subject to dilution of the analysed solution, by the linear dynamic range of the gas chromatograph column and detector or by the sample splitting capability of the analytical instrumentation used. The lower limit of the useful range depends on the noise level of the detector and on blank levels of analyte and/or interfering artefacts on the sampling devices or in the desorption solvent. Artefacts are typically sub-nanogram for activated charcoal, but higher levels of aromatic hydrocarbons have been noted in some batches.

Specifies a method for the measurement of the concentrations of airborne vapours in the range from approx. 1 mg/m^3 to 1 000 mg/m^3 when sampling 10 litres of air. Annexes A, B and C form an integral part of this standard. Annex D is for information only.

Specifies a method for the measurement of the concentrations of airborne vapours in the range from approx. 1 mg/m^3 to 1 000 mg/m^3 when sampling 10 litres of air. Annexes A, B and C form an integral part of this standard. Annex D is for information only.

ISO 17735:2009 gives general guidance for the sampling and analysis of airborne organic isocyanates in workplace air. ISO 17735:2009 is appropriate for a wide range of organic compounds containing isocyanate groups, including monofunctional isocyanates (e.g. phenyl isocyanate), diisocyanate monomers (e.g. 1,6-hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), and isophorone diisocyanate (IPDI), prepolymers (e.g. the biuret and isocyanurate of HDI), as well as intermediate products formed during production or thermal breakdown of polyurethane. In mixed systems of HDI and IPDI products, it is impossible to identify and quantify low levels of IPDI monomer using ISO 17735:2009, due to coelution of IPDI monomer with HDI-uretidinedione. The useful range of the method, expressed in moles of isocyanate group per species per sample, is approximately 1 x 10-10 to 2 x 10-7.

ISO/TR 17737:2007 provides guidelines which are intended to provide industrial hygienists, employers and workers with a broad overview of isocyanates, their uses in industry, methods of measurement and guidance on choosing the appropriate sampling strategy. This document discusses areas of concern to alert the industrial hygienist, employer and worker involved with the use of isocyanates to the importance of sampling and the key issues involved in choosing a sampling strategy for their workplace, and directs them to seek further information on the topic(s) of concern.

ISO 17734-1:2006 gives general guidance for the sampling and analysis of airborne isocyanates in workplace air. The method is suitable for the determination of a wide range of different isocyanates in both the gas and particle phases. Typical monofunctional isocyanates that can be determined are isocyanic acid (ICA), methyl isocyanate (MIC), ethyl isocyanate (EIC), propyl isocyanate (PIC), butyl isocyanate (BIC), and phenyl isocyanate (PhI). Typical monomeric diisocyanates include 1,6-hexamethylene- (HDI), 2,4- and 2,6-toluene- (TDI), 4,4'-diphenylmethane- (MDI), 1,5-naphthyl- (NDI), isophorone- (IPDI), and 4,4'-dicyclohexylmethane diisocyanate (HMDI). Multifunctional isocyanates that can be determined are typically oligomers in polymeric MDI, biuret-, isocyanurate-, and allophanate-adducts and prepolymeric forms of isocyanates.

ISO 17734-2:2006 gives general guidance for the sampling and analysis of airborne amines and aminoisocyanates in workplace air. The method can be used for simultaneous determinations of amines, 4,4'-methylenediphenyldiamine (4,4'-MDA), 2,4- and 2,6-toluenediamine (2,4-, 2,6-TDA) and 1,6-hexamethylenediamine (1,6-HDA), and compounds containing both isocyanate and amine groups, 4,4'-methylenediphenyl aminoisocyanate (4,4'-MAI), 2,4-, 4,2- and 2,6-toluene aminoisocyanate (2,4, 4,2, 2,6-TAI), 1,6-hexamethylene aminoisocyanate (1,6-HAI). The method is suitable for collecting amines and aminoisocyanates in both the gas and particle phases.

The procedure is valid for concentrations in the range from 250 g/m3 to 25 mg/m3. It is compatible with low flow-rate personal sampling equipment and can be used for personal and fixed location sampling. It cannot be used to measure instantaneous or short-term fluctuations of concentrations.