Formaldehyde test methods

Type 1 sample in the air above the water, type 2 sample in the water, EN ISO 14 184 part 1 = Japan Law 112, part 2 = AATCC 112. BS 6806 part 3 is a slight modification of AATCC 112. BS 6806 part 2 is called a free formaldehyde test method, but it also covers released formaldehyde, caused by elevated reaction temperature and the use of concentrated sulfuric acid for the colour development before colorimetrical determination. 

In the FTM-2 "Formaldehyde Test Method for Large Scale Test Chamber", the method allows a temperature correction factor to be applied to formaldehyde concentrations determined at temperatures other than the desired 25j 0.5 C. In addition, the states of Wisconsin and Minnesota allow temperature corrections of formaldehyde levels determined at temperatures other than 25 C for field complaint investigations. The temperature correction factors are based on the popular Berge Equation (25). 

Researchers had noted the release of formaldehyde by chemically treated fabric under prolonged hot, humid conditions (85,86). The American Association of Textile Chemists and Colorists (AATCC) Test Method 112 (87), or the sealed-jar test, developed in the United States and used extensively for 25 years, measures the formaldehyde release as a vapor from fabric stored over water in a sealed jar for 20 hours at 49°C. The method can also be carried out for 4 hours at 65°C. Results from this test have been used to eliminate less stable finishes. 

Prior to 1965, it was not unusual for unwashed finished fabrics to release 3—5000 ppm of formaldehyde when tested by an AATCC test method. Formaldehyde release was reduced to the level of 2000 or less by appHcation of DMDHEU or dimethyl olcarhama tes. This level was reduced to approximately 1000 in the mid-1970s. Modification of the DMDHEU system and use of additives demonstrated that release values below 100 ppm were achievable. As of this writing (1997), good commercial finishing ranges between 100 and 200 ppm of formaldehyde release. 

Detection of Preservatives.—Tests are made especially for salicylic acid, boric acid and formaldehyde, the methods given for wine being employed. 

Test method for determination of formaldehyde and other carbonyl compounds in air (active sampler methodology)... 

D 1490 Test Method for Non-volatile Content of Urea Formaldehyde of Resin... 

E.G.C Clark s Isolation and Identification of Drugs (The Pharmaceutical Press, London) specifies a method for making "microtests of a "pedant drop or "microdrop. The sulfuric acid-formaldehyde testing of DMT, to illustrate, yields dull orange with a sensitivity of 1.0 meg. sensitivity, while the ammonium molybdate test yields blue going to green and then yellow with a sensitivity of 0.1 meg. 

The second type of test is intended to simulate extraction of formaldehyde by perspiration. This test determines mainly the free formaldehyde that is dissolved in the test liquid during a direct extraction. The test liquid can be water only or water with specific additives like wetting agents or buffer salts. Some of the more important formaldehyde analysis methods are given in Table 5.9. 

DANSET 384 is a textile finishing resin which has been designed to afford extremely low formaldehyde evolution from fabrics finished with it. It will afford formaldehyde odor level potential values of below 200 ppm by AATCC Test Method 112-1978 for partially or fully cured finishes on properly prepared and finished fabrics without afterwashing. 

Formaldehyde odor values of below 500 ppm, as measured by AATCC Test Method 112-1979, are normal on finished fabrics which have been treated with DANSET JS. Formaldehyde odor in the finishing plant is also low with DANSET JS. 

In the USA, the regulatory focus is on consumer and worker exposure to formaldehyde vapors released from the fabric, so the test method specified is AATCC Test Method 112-2003. In this method, 1 g of fabric is suspended over 50 ml of distilled water in a sealed quart jar. The jar is placed in an oven for either 4 h at 65 °C or 20 h at 49 °C. Any formaldehyde vapors generated are absorbed by the water. An aliquot of the formaldehyde-water solution is taken and analyzed colorimetrically using the Nash reagent.Typical levels of formaldehyde found in properly processed fabrics treated with modem cross-linking reagents are less than 100 ppm. The Nash method is based on the reaction of acetylacetone with formaldehyde and an ammonium salt to form a yellow complex with an absorbance maximum at 414 nm. The mild conditions of the reaction ( pH 7, 5 min at 58 °C) eliminate many potential interferences. 

High-pressure liquid chromatography (HPLC) allows the separation of soluble materials into component parts based on the partitioning of the materials between a mobile (solvent) and stationary (column packing) phase. With proper choice of solvent and column packing, separation of many types of materials is possible. HPLC has been used successfully to determine reagent residues on fabrics treated with durable press finishes as well as detennining formaldehyde levels in aqueous solutions obtained by the AATCC Test Method 112. ... 

AATCC Test Method 112-2003, Formaldehyde Release from Fabrics, Determination of Sealed Jar Method , Technical Manual of the American Association of Textile Chemists and Colorists, Research Triangle Park, American Association of Textile Chemists and Colorists, 2003, 176-178. 

Product tests. Clearly, the best product test is full-scale testing of finished panels under actual use conditions. This has been done (27,38) but is expensive, because several full-sized panels of each product must be pre-conditioned at constant temperature and humidity for at least a week. The next best approach is to test product samples in air chambers under standardized conditions. A summary of such methods is contained in Table I. A very large effort has been made over the last three decades world-wide to develop quick, reliable and meaningful product tests. Wittmann (16), Zartl (20), Plath (17), Verbestel (1, Neusser (21,22), Roffael (25), HUD, the U.S. Forest Products Industry (39,40), many standaraization organizations (41-43) and others have published many viable methods, but the testing involves a combination of complex factors and there is simply no single test that fulfills everybody s specific needs. Table I list some of the currently accepted test methods for formaldehyde emission from particleboard, plywood and medium density fiberboard. 

Manufactured Home Construction and Safety Standard, Air Chamber Test Method for Certification and Qualification of Formaldehyde Emission Levels," U.S. Code of Federal Regulations, Vol. 24, Part 3280.406, (U.S. Department of Housing and Urban Development), and F eral Register, Vol. 48, pg 37136-37195, 1983. 

Sma11 Sea Ie Test Method for Determ i n i ng Forma Idehyde Em i ss i on from Wood Products, Two Hour Dessicator Test, FTM-1," National Par id eboard Association, Hardwood Plywood Manufacturers Association, Formaldehyde Institute and U.S. Department of Housing and Urban Development, Federal Register, 1982, 48, 37169. 

Hardwood plywood products are decorative in nature and are designed for interior use. Over 95X of all hardwood plywood is made with urea-formaldehyde adhesives. Responding to concerns about formaldehyde and certain wood products, test methods for measuring surface emissions were developed in the early 1980 s. Emissions from most hardwood plywood and particleboard products have decreased 65% to 95% in recent years primarily by use of low emitting UF adhesives and/or scavengers. Good correlation has been demonstrated between product test methods and indoor levels of formaldehyde in experimental manufactured homes. Decorative surface finishes can act to either increase or decrease surface emissions, depending on the nature of the finish and the substrate. 

Small scale test method for determining formaldehyde emissions from wood products, two-hour desiccator test, FTM 1, Reston, VA. 

G. Gramp, W. Groah. "Evaluation of the relationship between formaldehyde emission from particleboard mobile home decking and hardwood plywood wall paneling as determined by product test methods and formaldehyde levels in experimental mobile homes." U.S. Dept. of Housing and Urban Development, 1982. 

Large-Scale Test Method For Determining Formaldehyde Emissions From Wood Products — Large Chamber Method, FTM 2-1983 National Particleboard Association Gaithersburg, MD, 1983. 

These test chambers can be incorporated to the enzymatic methods for formaldehyde determination. Formaldehyde emissions of a product, or mix of products, to the ambient air can be collected in distilled water or 1% sodium bisulfite as the absorbing solution. After collection, formaldehyde samples are analyzed as described above. In the mobile home simulator test method (2J, double or triple impingers, which are placed in series, should be used in order to collect all of the formaldehyde vapor. The test conditions should simulate the actual environment. Several factors such as temperature and relative humidity of the system including the specimens and background of formaldehyde in the test chamber, affect the precision and accuracy of the results. It has been shown that a 7 C change in temperature doubles the emission level (L). The temperature of the test chamber should be... 

The effect on particleboard of an ammonia treatment can also be shown using this testing method. In figure 8 again the ideal mixing model is applied. Notice that the line with the lowest emission is the one on the top. The reason is that the reciprocal values and not the steady state formaldehyde concentrations as such, are plotted. Here the slope is different as well. 

This paper presents Georgia-Pacific s and other investigators experience with various aspects of large environmental chamber design and operation. Experimental data and observations are presented in such topics as 1.) Common formaldehyde air test methods 2.)... 

Formaldehdye generation and recovery studies 3.) Air exchange measurement techniques 4.) Preconditioning of test boards 5.) Temperature effect on chamber formaldehyde concentrations 6.) Relationship of popular quality control test methods to the large chamber 7.) Loading, air exchange rate, and wood product combination effects on chamber formaldehyde concentrations 8.) Chamber Round Robin studies between Georgia-Pacific s chamber and other outside lab chambers 9.) Chamber concentrations and its relationship to actual field measurements. 

All quality control tests and specimen conditioning are conducted under carefully controlled environmental conditions, i.e. temperature = 24 H3.5 C, 50h 5% relative humidity and a background formaldehyde level of less than 0.1 ppm. Ourselves as well as others have found that temperature effects on the quality control test values follow the same pattern observed in the large scale chamber (30). In short, the Berge temperature correction can be applied to the quality control test methods. 

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