Formaldehyde release methods

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. 

Determination of formaldehyde release. Part 2 Formaldehyde release by the gas analysis method... 

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. 

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. 

Roffael (15) measured formaldehyde emissions from a phenolic particleboard using the WKI-Method which involves suspending small samples over 50 cm of distilled water in tightly closed polyethylene bottles and measuring formaldehyde levels in the water after varying times. Temperatures were maintained at 42 C. This work indicated that formaldehyde release from the phenolic particleboards ceased after a relatively short reaction period (approximately 96 hours). This finding is consistent with the resin stability considerations discussed previously under theoretical considerations. 

In these studies, formaldehyde release rate coefficients were measured for different consumer products using two methods. 

In one series of studies, a small static chamber with no ventilation, which was a modification of the Japanese Industrial Standard (JIS) desiccator procedure, was used to compare formaldehyde release from a number of products (1, 7-14). In a second series of studies, a chamber with ventilation rates similar to those in houses was used to more closely mimic actual product use. With this method, combined formaldehyde release from two products placed in the same chamber was compared to their separate releases. 

Unwashed new clothing samples (Table IIC), fiberglass insulation products with formaldehyde resins (Table IID), paper products (Table HE), fabrics (cotton, nylon, olefin, and blended) (Table HF), and carpets (Table HG), had substantially 3 to > 100 fold) lower formaldehyde release rate coefficients, as measured by this method, than did pressed wood products or urea formaldehyde foams (1, 15). 

Enzymatic Methods for Determining Formaldehyde Release from Wood Products... 

Two sensitive fluorometric enzymatic methods for the determination of formaldehyde release from wood products were described. These methods were developed using the enzyme formaldehyde dehydrogenase to catalyze the oxidation of formaldehyde to form formic acid and NADH in the presenc of oxidized nicotinamide adenine dinucleotide (NAD ). The increase in NADH, which is directly proportional to the concentration of formaldehyde, is measured fluorometrically at em ... 

The measurement of formaldehyde release from wood products Involves the collection of formaldehyde vapor in the test chamber using a suitable absorbing solution and then analyzing the formaldehyde collected. For many years, formaldehyde emission measurements were carried out using the desiccator test sampling method due to... 

We have developed two novel new enzymatic fluorometric methods for the trace analysis of formaldehyde. Due to their simplicity, sensitivity and specificity, these methods should find wide applications in the monitoring of formaldehyde released from wood products. As we stated above, enzymatic fluorometric method II does offer higher sensitivity and better detection limit over enzymatic fluorometric method I. However, method II requires two... 

In cooperation with DSM, MCN developed a method of measurement for the determination of the formaldehyde release from particle board, based on a theorie for mass transfer, implying that under steady state conditions the emission of formaldehyde of a given particle board can and should be defined by two parameters of the particular board. These two parameters are (1) Ce defined as the equilibrium formaldehyde concentration (with ventilation rate 0") and (2) kgg defined as the overall mass transfer coefficient of the board. In (ideal mixed) climate rooms the stationary formaldehyde... 

Woodbased panels have also been tested with the perforator method. This method is European Norm according to CEN and gives an estimate of the extractable content of formaldehyde for especially particle boards. Formaldehyde release has also been investigated for different kind of pieces of furniture exposed in area to volume proportions in which they can be found in a small room. 

The purpose of this study was to evaluate laboratory formaldehyde release test methods for predicting real-life formaldehyde air concentrations human exposure levels, and health risk. Three test methods were investigated the European perforator test, the gas analysis method at 60 C and 3% RH, and the gas analysis method at 23 C and 55% RH. Different types of particleboard bonded with urea-formaldehyde and urea-melamine-formaldehyde resins were tested. The results were used to rank boards as a function of test method, conditioning, short-term humidity, and temperature variations during storage. Additional experiments were conducted in small experimental houses at a Dutch research institute. Our conclusions are that relative ranking of products is influenced by the test method and by change in relative humidity. The relationship between test method and release in real-life situations is not clear. In fact, it seems impossible to use laboratory measurements to predict real-life product performance of board if the board is not fully in equilibrium with the atmosphere. 

Formaldehyde emission from particleboard has been studied at our laboratory for over 15 years. We search for an answer to the following question Given the fact that amino-resin bonded wood products have the ability to release formaldehyde into indoor air when they are in use, what simple and rapid analysis method can be used at the time of manufacture to predict formaldehyde release under use conditions as quantitatively as possible Obviously, the chosen method needs to be applicable for all types of boards that are available on the market. 

This is not true for the formals which do not exhibit remarkable antimicrobial activity. Exception (3-iodopro-pargyl)-(4-chlorophenyl) formal (3.1.6.) the antimicrobial activity of which is not based on the formaldehyde incorporated into the molecule. It can pass for a rule that formaldehyde releasing compounds are effective if their formaldehyde contents can be analysed in diluted aqueous solutions using the method described by (Tanenbaum Bricker (1951) (reaction of the compounds with phenylhydrazine and potassium hexacyanoferrate). However,... 

The 1,3-oxazolidines listed here are highly soluble in water and polar solvents, and in oils, too. Aqueuos solutions have a basic pH. The formaldehyde releasable is detectable by the Tanenbaum method in consequence the antimicrobial effectiveness of the 1,3-oxazolidines corresponds to their formaldehyde content. 

Local restrictions concerning the inclusion of preservatives and other constiments are dependent on the cosmetic product s method of use. Products that are allowed to remain on the skin are differentiated from those that are meant to be rinsed off. Components of products left on the skin can be expected to penetrate the viable epidermis and to be systematically absorbed. Products that are rinsed off shortly after skin contact, such as shampoos, can, if properly labeled, contain preservatives that might elicit adverse reactions if left on the skin. Typical examples of such preservatives are formaldehyde, formaldehyde releasers such as Quaternium 15 or MDM hydantoin, and the blend of methylchloroiso-thiazolinone and methylisothiazolinone. 

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