This International Standard gives general guidance for the sampling and analysis of airborne organic isocyanates in workplace air, using the 2-(1-methoxyphenyl) piperazine reagent and liquid chromatography.
This International Standard is applicable to the measurement of a wide range of organic compounds containing isocyanate functional groups (NCO), including isocyanate monomers and prepolymers.
This International Standard is applicable to the measurement of any product containing free isocyanate groups.
This International Standard is applicable to the measurement of time-weighted-average concentrations of organic isocyanates in workplace atmospheres, and for sampling over periods in the range 10 min to 8 h. It is designed for personal monitoring, but may also be used for fixed-location monitoring by suitable modification.
This International Standard is applicable to the measurement of airborne organic isocyanates in the concentration range approximately 0,1 μg NCO·mto 140 μg NCO·m for a 15 I sample volume.
The qualitative and quantitative detection limits for isocyanate, defined as three times and ten times the standard deviation of six blank determinations, have been found to be typically around 0,001 μg NCO and 0,004 μg NCO per sample respectively (electrochemical detection). For a 15 I air sample, these values correspond to qualitative and quantitative detection limits of 0,07 μg·m and 0,3 μg·m respectively.
EXAMPLES Aromatic monomers include toluene diisocyanate (TDI) and methylene bis(4-phenyl isocyanate) (4,4-diisocyanatodiphenylmethane, MDI). Aliphatic monomers include isophorone diisocyanate (IPDI) and 1,6-hexamethylene diisocyanate (HDI). Isocyanate oligomers or prepolymers are derived from these monomers by self-condensation or reaction with polyols.
NOTE 1 Organic isocyanates can also arise from thermal decomposition of polyurethanes. If both isocyanates and amines are believed to be present, use of a standard which enables the simultaneous determination of both amines and isocyanates may be more appropriate (ISO method in draft). An alternative procedure using the MAP [1-(9-anthracenylmethyi)piperazine] reagent is also available (ISO method in draft).
NOTE 2 The objective of air monitoring is usually to determine worker exposure and, therefore, the procedures described in this International Standard are for personal sampling in the breathing zone. The procedures may be used for background or fixed location sampling. However, it should be recognized that, due to aerodynamic effects, samplers designed for personal sampling do not necessarily exhibit the same collection characteristics when used for other purposes.
ISO 16702:2001 history
2007ISO 16702:2007 Workplace air quality - Determination of total organic isocyanate groups in air using 1-(2-methoxyphenyl)piperazine and liquid chromatography
2001ISO 16702:2001 Workplace air quality - Determination of total isocyanate groups in air using 2-(1-methoxyphenyl) piperazine and liquid chromatography