Acrolein Test Method Advisory and Data
There is currently no CARB-approved test method for acrolein from stationary sources. Until more is known about acrolein emissions, local air districts must determine on a case-by-case basis how they will implement their toxics programs.
On April 28, 2000, the ARB sent an advisory to the local air districts titled "Advisories to Limit Use of ARB Method (M430) Determination of Formaldehyde and Acetaldehyde in Emissions From Stationary Sources" which read:
Method 430 (M430) was last amended on December 13, 1991, by the Air Resources Board (ARB). M430 is based on collecting samples with impingers containing DNPH and analyzing the samples by HPLC. The method was developed to determine formaldehyde and acetaldehyde from stationary sources. In the intervening years, many studies have contributed to ARB staff's knowledge of aldehyde sampling and analysis. Unfortunately, all new information about M430 limits its applicability strictly to formaldehyde and acetaldehyde under certain conditions. Until an improved test method is identified, ARB has developed the following advisories warning against misuse of M430.
First Advisory: Do not use M430 for the determination of any aldehyde(s) other than formaldehyde and acetaldehyde; especially, do not use M430 for the determination of acrolein.
Second Advisory: Any data or results, based on the use of M430 to determine acrolein, or aldehyde(s) other than formaldehyde and acetaldehyde, are suspect and should be flagged as non-quantitative wherever they appear.
Third Advisory: Any data or results, based on the use of M430 to determine formaldehyde and acetaldehyde in emissions containing over 50pmvd (parts per million volume dry) of oxides of nitrogen (NOx), are suspect and should be flagged as non-quantitative whenever they appear.
Background for the First Advisory: M430 has always been clear in its stated limitations regarding applicability. The statement of applicability limits its application to determination of formaldehyde and acetaldehyde in emissions from stationary sources. Nevertheless, statutory requirements for acrolein testing of emissions from stationary sources have led to the use of M430 for acrolein. ARB staff has warned against the use of M430 whenever contacted regarding such testing.
The technical limitation for M430 and acrolein involves the strong acid in the sampling train. Acrolein has a double bond that is rapidly degraded by acid. This leads to underestimation of the acrolein emissions. A partial "fix" for this problem was published as a circular by Air Toxics LTD. It involves mixing the sample with a strong organic solvent to pull the acrolein out of the acid, limiting the degradation of acrolein. This is to be done as soon as possible after sampling.
After further work, Air Toxics LTD. published a more comprehensive treatment of M430 problems with acrolein. According to their research, after 30 minutes in the sampling acid more than 60% of the sampled acrolein is lost. After one hour, 70% is gone. This is bad news since the typical sampling time is one hour. Based on this study, M430 cannot be used to determine acrolein.
Background for the Second Advisory: The preceding background for the first advisory casts serious doubt on any date or results using M430 for anything but the determination of formaldehyde or acetaldehyde. For example, the degree of acrolein degradation is not always 60% at 30 minutes, but varies from test to test unpredictably. An example of a set of results rendered void by the second advisory is the large M430 acrolein database compiled per the California "Toxic Hot Spots Act".
Background for the Third Advisory: The sampling acid in M430 is charged with a complexing agent before each test. The agent combines with aldehydes to prepare them for detection at the laboratory. If this combination does not occur, the formaldehyde or acetaldehyde cannot be quantified.
The complexing agent also combines with NOx. Any such NOx-agent combinations prevent aldehyde-combinations with that complexing agent. With enough NOx combinations, there will not be enough complexing agents for aldehyde quantification at the laboratory. For typical M430 sampling trains, this problem for aldehyde quantification occurs when the NOx concentration is 50ppmvd or higher.
For questions regarding acrolein measurements, please contact Mr. Chris Halm (916) 323-4865.
There is currently no ARB-approved test method for acrolein from stationary sources. Until more is known about acrolein emissions, local air districts must determine on a case-by-case basis how they will implement their toxics programs. Additional information, including a research report that describes what we do know about the existing test methods, and details about ambient acrolein measurements, is provided below.
U.S. EPA's ambient method for aldehydes: TO-5
Additional Acrolein Information on Test Methods in Development
Draft Modified Stationary Source Test Method CARB 430 - MSWord (38k)
Ashland - Lawn Mower Emissions with Modified M430 - MSWord (2,309k)
Sucha Parmar - Retention Study of Acrolein with M430 Paper #1 - Paper #2
Japanese paper - hydroxylamine derivatization ( MSWord 108k)
For questions, please contact Mr. Chris Halm (916) 323-4865.