Standards emissions testing methods

Many standard emissions test methods and protocols require measurement of the TVOC emission rate in addition to that of individual compounds. This is usually obtained from the GC data by summing the masses of every individual analyte which elutes within a particular range (typically n-C6 to n-C16), on a nonpolar capillary GC column. Detailed procedures for this vary, with some protocols calling for individual measurements to be made by FID, others by MS. Similarly some protocols require individual compounds to be calibrated using authentic standards (i.e., standards of each specific compound found) while others allow measurements of all the individual compounds which contribute to a TVOC data point to all be calibrated as toluene (that is, in toluene equivalents ). 

The standard astm test method (D-1149-64) for rubber damage includes a test chamber (volume, 0.11-0.14 m ) through which ozonized air flows at a rate greater than 0.6 m/s. Because the residence time of the ozonized air in the test chamber is about 1 s, the ozone may be expected to reach the material in about 0.1 s. A somewhat similar test procedure (aatcc test method 109-1972 ansi L14, 174-1973) is used in testing colorfastness. The ozone generator is usually (but not necessarily) a mercury-vapor resonance lamp with emission lines at 184.9 and 253.7 nm. The 184.9-nm line is absorbed, and two ground-state oxygen atoms are produced ... 

Standardized Methods for Testing Emissions of Organic Vapors Table 6.1 List of prominent standard material emissions test methods and protocols. 

Standard Test Methods on the other hand, specify procedures for carrying out measurements. In the case of emissions testing, methods are usually broken down into multiple separate sections covering sampling frequency, sample collection and preparation, emissions testing and vapor analysis (see below.) Test methods may also include lists of target compounds or compounds that are commonly... 

Continuing with the above example of ER3 of the European Construction Products Directive horizontal emissions test methods (i.e., applicable to multiple product types) have been developed by CEN and ISO for compliance with the CPD and are now available as parts 6, 9,10 and 11 of EN/ISO standard 16000 (see Table 6.1). Furthermore, a program of work led by CEN TC351 has now been instigated under European Council Mandate M/366 to amalgamate and validate these standards. Once this work is completed (estimated 2010) it is understood that chemical emissions testing will become a mandatory part of CE marking for construction products. 

Test or Certification Protocols and/or Product Standards are similar to standard test methods but include additional criteria (requirements). Typical test protocols or product standards specify which emission test method should be used, when it should be carried out (for example 3 days, 12 days or 28 days after the sample has been placed in the test apparatus), a list of target compounds (i.e., which compounds or groups of compounds are to be measured) and pass/fail criteria (i.e., limit levels for emissions above which a product would fail the certification process because one or more compounds are being emitted from that product material at an unacceptably high rate.)... 

Low temperature/surface-only thermal extraction/microchamber methods have recently been evaluated to see if the results obtained provide better correlation with standard emissions tests (GUT, 2008 VDI, 2008 Schripp et al., 2007 HEMICPD, 2009) and whether or not they can be used to accurately and rapidly predict product performance with respect to chemical emissions after 3 or 28 days. Some of these studies are still on going but results have been very positive and have already led to the consideration/development of several low temperature, surface extraction methods for emissions screening (ASTM, 2008 GUT, 2008 VDI, 2008). 

If the additional variables of sample selection, transport and preparation and chamber/cell emissions testing are taken into account, overall uncertainty for emissions testing methods is likely to be in the range 30-50%, even with best practice. Pass/fail criteria in associated test protocols and product standards, must take this into account. 

The proposed test methods is the basis for future type test standards including test methods and procedures to determine heat output, efficiency and emissions of slow heat releaseappliances. 

ASTM. 1998a. ASTME1613. Standard test method for analysis of digested samples for lead by inductively coupled plasma atomic emission spectrometry (ICP-AES). Flame Atomic Absorption (FAAS), or Graphite Furnace Atomic Absorption (GFAA) Techniques. American Society for Testing and Materials. 

ASTM D-6349. Standard Test Method for Determination of Major and Minor Elements in Coal, Coke, and Solid Residues from Combustion of Coal and Coke by Inductively Coupled Plasma-Atomic Emission Spectrometry. 

There is also a standard test method for determination of major and minor elements in coal ash by inductively coupled plasma (ICP)-atomic emission spectrometry (ASTM D-6349). In the test method, the sample to be analyzed is ashed under standard conditions and ignited to constant weight. The ash is fused with a fluxing agent followed by dissolution of the melt in dilute acid solution. Alternatively, the ash is digested in a mixture of hydrofluoric, nitric, and hydrochloric acids. The solution is analyzed by (ICP)-atomic emission spectrometry for the elements. The basis of the method is the measurement of atomic emissions. Aqueous solutions of the samples are nebulized, and a portion of the aerosol that is produced is transported to the plasma torch, where excitation and emission occurs. Characteristic line emission spectra are produced by a radio-frequency inductively coupled plasma. A grating monochromator system is used to separate the emission lines, and the intensities of the lines are monitored by photomultiplier tube or photodiode array detection. The photocurrents from the detector... 

Coal contains several elements whose individual concentrations are generally less than 0.01%. These elements are commonly and collectively referred to as trace elements. These elements occur primarily as part of the mineral matter in coal. Hence, there is another standard test method for determination of major and minor elements in coal ash by ICP-atomic emission spectrometry, inductively coupled plasma mass spectrometry, and graphite furnace atomic absorption spectrometry (ASTM D-6357). The test methods pertain to the determination of antimony, arsenic, beryllium, cadmium, chromium, cobalt, copper, lead, manganese, molybdenum, nickel, vanadium, and zinc (as well as other trace elements) in coal ash. 

Infrared absorption is one of three standard test methods for sulfur in the analysis sample of coal and coke using high-temperature tube furnace combustion methods (ASTM D-4239). Determination of sulfur is, by definition, part of the ultimate analysis of coal (Chapter 4), but sulfur analysis by the infrared method is also used to serve a number of interests evaluation of coal preparation, evaluation of potential sulfur emissions from coal combustion or conversion processes, and evaluation of the coal quality in relation to contract specifications, as well as other scientific purposes. Infrared analysis provides a reliable, rapid method for determining the concentration of sulfur in coal and is especially applicable when results must be obtained rapidly for the successful completion of industrial, beneficiation, trade, or other evaluations. 

Table 5.1 Standard chamber and cell methods for emission testing.

ISO (2006a) 16000-9. Indoor Air-Determination of the Emission of Volatile Organic Compounds from Building Products and Furnishing-Emission Test Chamber Method, International Organization for Standardization, Geneva, Switzerland. 

To satisfactorily meet and address these regulatory and market needs, standard methods for emissions testing need to be both robust and repeatable for competent laboratories to carry out, and practical and affordable for manufacturing industry. Uniformity of test methods, between countries and markets is also important if manufacturers are to avoid having to submit the same products for emissions testing by multiple different emissions certification protocols. 

Materials Emissions Testing A Challenge for Method Standardization... 

For emissions testing to be accepted as a meaningful and necessary part of product quality assessment, relevant test methods must ensure acceptable uncertainty. Any associated products standards, incorporating pass/fail criteria, must also take into account the actual uncertainty of the standard methods specified. A relatively detailed summary of some of the major potential causes of error in the multistep materials emissions testing process is presented later in this chapter (see Section 6.6.2). For an emissions test standard/protocol to be robust and useful, it must take into account all of these issues and include sufficient guidance to ensure that a competent laboratory can achieve results within the expected uncertainty limits. 

The International Organization for Standardization (ISO) Technical Committee (TC)146 sub-committee (SC)6 maintains the main EN ISO 16000-series of test methods for emissions testing and associated IAQ (see Table 6.1) and is working in conjunction with ISO TC 22 (cars) to harmonize associated test methods for in-vehicle air quality monitoring and emissions from car trim components. 

It is interesting that regulations such as these are not effective in isolation. For example ER 3 of the CPD, requiring that chemical emissions from products used indoors must not adversely impact the indoor environment, became European law in 1989. However, it has not yet been effectively implemented. This is partly because there has not, hitherto, been a validated and broadly applicable (horizontal) standard test method available to carry out emissions measurement in compliance with the regulation. 

Standard test Methods for Formal Evaluation and Certification of Emissions... 

Standard Methods and Protocols for Emissions Testing Current Status... 

A list of the most prominent materials emissions standards and test protocols is presented in Table 6.1. The current level of method development activity is such that it is difficult to be confident that all relevant standard methods, both published and in later stages of development, have been included, but care has been taken to try to make this list as comprehensive as possible. 

Storage of samples between tests is another potential source of error. In an ideal world, samples should be kept in the chamber or under the cell throughout an emission test. However, given that many standard methods and protocols require a 2- or 4-week evaluation and that each fully configured emissions test... 

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