Material emissions – Vehicle interior air quality
The need for VIAQ monitoring
Emissions from vehicle trim components (PVC, polyurethane, foam, carpets, adhesives etc.) can adversely affect vehicle interior air quality (VIAQ), and subsequently the comfort and health of drivers and passengers.
As a result of these concerns, VIAQ is of growing importance to the automotive industry, mainly due to market image but ever more due to the increase of industry regulation. This has been reflected in the development of harmonised methods to quantitate releases of chemicals released from the materials used, and assess the overall quality of in-vehicle air.
Using these methods, the emission levels and potential impact of any given car trim component can be evaluated, and the levels of volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs, i.e. fogging compounds) and specific malodorous compounds emitted under different conditions can be determined.
Target compounds and sampling methods
Target compounds include formaldehyde, acetaldehyde, benzene, styrene, xylenes and phthalates, and limit levels are specified by various automobile associations, including:
Over the years, hundreds of manufacturer-specific methods have been developed for the sampling and analysis of VOCs and SVOCs, and these employ numerous analytical techniques.
Some widely-used methods are:
Therefore, to simplify matters for the industry, the International Standards Organization recently convened a technical committee (ISO/TC 146/SC 6) to develop harmonised methods (see below).
What Markes can offer
Thermal desorption (TD)–GC–MS – for example, using Markes’ UNITY-xr and TD100-xr thermal desorbers – and related sampling methods can help analysts determine and quantify the compounds affecting VIAQ. This can be done in one of three main ways:
|Harmonised methods || |
Four methods have been developed by ISO/TC 146/SC 6 for sampling VOCs and SVOCs from vehicle interiors and the materials used in them:
Three further methods are in preparation:
- For discussion of the application of thermal desorption to the monitoring of vehicle cabin air, see Application Notes 028 and 033.
- For an example of the use of direct desorption to detect VOCs and SVOCs from furnishings and car trim, see Application Notes 040 and 059.
- For more information on the use of small chambers, Tedlar® or Mylar® bags, and microchambers, see Application Notes 067, 069, 073 and 074.
- For additional examples of the use of Markes’ Micro-Chamber/Thermal Extractor, see Application Notes 068, 093 and 103.
- For a more in-depth discussion of standard methods relevant to in-vehicle air, see: M. Wensing, Standard test methods for the determination of VOCs and SVOCs in automobile interiors, in: Organic Indoor Air Pollutants, ed. T. Salthammer and E. Uhde, Wiley-VCH, 2009, pp. 147–161.
- For a description of Markes’ Micro-Chamber/Thermal Extractor, its application (with UNITY-ULTRA) to assess emissions from plastic pellets, wall coverings and polyurethane foams, and correlation with small-chamber methods, see: T. Schripp et al., A microscale device for measuring emissions from materials for indoor use, Analytical and Bioanalytical Chemistry, 2007, 387: 1907–1919.
The following pages may also be of interest: