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Dry sampling of gas-phase isocyanates and isocyanate aerosols from thermal degradation of polyurethane

Gylestam, Daniel; Riddar, Jakob B. LU ; Karlsson, Daniel; Dahlin, Jakob LU ; Dalene, Marianne LU and Skarping, Gunnar LU (2014) In Annals of Occupational Hygiene 58(1). p.28-49
Abstract

The performance of a dry sampler, with an impregnated denuder in series with a glass fibre filter, using di-n-butylamine (DBA) for airborne isocyanates (200ml min-1) is investigated and compared with an impinger flask with a glass fibre filter in series (1 l min-1). An exposure chamber containing 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and 2,4- and 2,6-toluene diisocyanate (TDI) in the concentration range of 5-205 μg m-3 [0.7-33 p.p.b.; relative humidity (RH) 50%], generated by gas- and liquid-phase permeation, was used for the investigation. The precision for the dry sampling for five series with eight samplers were in the range of 2.0-6.1% with an average of 3.8%. During... (More)

The performance of a dry sampler, with an impregnated denuder in series with a glass fibre filter, using di-n-butylamine (DBA) for airborne isocyanates (200ml min-1) is investigated and compared with an impinger flask with a glass fibre filter in series (1 l min-1). An exposure chamber containing 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and 2,4- and 2,6-toluene diisocyanate (TDI) in the concentration range of 5-205 μg m-3 [0.7-33 p.p.b.; relative humidity (RH) 50%], generated by gas- and liquid-phase permeation, was used for the investigation. The precision for the dry sampling for five series with eight samplers were in the range of 2.0-6.1% with an average of 3.8%. During 120-min sampling (n = 4), no breakthrough was observed when analysing samplers in series. Sixty-four exposed samplers were analysed after storage for 0, 7, 14, and 21 days. No breakdown of isocyanate derivatives was observed. Twenty-eight samplers in groups of eight were collecting isocyanates during 0.5-32h. Virtually linear relationships were obtained with regard to sampling time and collected isocyanates with correlation coefficients in the range of 0.998-0.999 with the intercept close to the origin. Pre- or post-exposure to ambient air did not affect the result. Dry sampling (n = 48) with impinger-filter sampling (n = 48) of thermal decomposition product of polyurethane polymers, at RH 20, 40, 60, and 90%, was compared for 11 isocyanate compounds. The ratio between the different isocyanates collected with dry samplers and impinger-filter samplers was in the range of 0.80-1.14 for RH = 20%, 0.8-1.25 for RH = 40%, 0.76-1.4 for RH = 60%, and 0.72-3.7 for RH = 90%. Taking into account experimental errors, it seems clear that isocyanic acid DBA derivatives are found at higher levels in the dry samples compared with impinger-filter samplers at elevated humidity. The dry sampling using DBA as the reagent enables easy and robust sampling without the need of field extraction.

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author
publishing date
type
Contribution to journal
publication status
published
keywords
airborne isocyanates, dibutylamine derivatives, dry sampling, liquid chromatography-mass spectrometry, thermal decomposition
in
Annals of Occupational Hygiene
volume
58
issue
1
pages
22 pages
publisher
Oxford University Press
external identifiers
  • scopus:84893081885
ISSN
0003-4878
DOI
10.1093/annhyg/met046
language
English
LU publication?
no
id
196c935a-f71c-4878-93cd-d9e030c6be75
date added to LUP
2016-10-14 10:51:27
date last changed
2017-08-27 06:25:37
@article{196c935a-f71c-4878-93cd-d9e030c6be75,
  abstract     = {<p>The performance of a dry sampler, with an impregnated denuder in series with a glass fibre filter, using di-n-butylamine (DBA) for airborne isocyanates (200ml min<sup>-1</sup>) is investigated and compared with an impinger flask with a glass fibre filter in series (1 l min<sup>-1</sup>). An exposure chamber containing 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and 2,4- and 2,6-toluene diisocyanate (TDI) in the concentration range of 5-205 μg m<sup>-3</sup> [0.7-33 p.p.b.; relative humidity (RH) 50%], generated by gas- and liquid-phase permeation, was used for the investigation. The precision for the dry sampling for five series with eight samplers were in the range of 2.0-6.1% with an average of 3.8%. During 120-min sampling (n = 4), no breakthrough was observed when analysing samplers in series. Sixty-four exposed samplers were analysed after storage for 0, 7, 14, and 21 days. No breakdown of isocyanate derivatives was observed. Twenty-eight samplers in groups of eight were collecting isocyanates during 0.5-32h. Virtually linear relationships were obtained with regard to sampling time and collected isocyanates with correlation coefficients in the range of 0.998-0.999 with the intercept close to the origin. Pre- or post-exposure to ambient air did not affect the result. Dry sampling (n = 48) with impinger-filter sampling (n = 48) of thermal decomposition product of polyurethane polymers, at RH 20, 40, 60, and 90%, was compared for 11 isocyanate compounds. The ratio between the different isocyanates collected with dry samplers and impinger-filter samplers was in the range of 0.80-1.14 for RH = 20%, 0.8-1.25 for RH = 40%, 0.76-1.4 for RH = 60%, and 0.72-3.7 for RH = 90%. Taking into account experimental errors, it seems clear that isocyanic acid DBA derivatives are found at higher levels in the dry samples compared with impinger-filter samplers at elevated humidity. The dry sampling using DBA as the reagent enables easy and robust sampling without the need of field extraction.</p>},
  author       = {Gylestam, Daniel and Riddar, Jakob B. and Karlsson, Daniel and Dahlin, Jakob and Dalene, Marianne and Skarping, Gunnar},
  issn         = {0003-4878},
  keyword      = {airborne isocyanates,dibutylamine derivatives,dry sampling,liquid chromatography-mass spectrometry,thermal decomposition},
  language     = {eng},
  number       = {1},
  pages        = {28--49},
  publisher    = {Oxford University Press},
  series       = {Annals of Occupational Hygiene},
  title        = {Dry sampling of gas-phase isocyanates and isocyanate aerosols from thermal degradation of polyurethane},
  url          = {http://dx.doi.org/10.1093/annhyg/met046},
  volume       = {58},
  year         = {2014},
}