Environ. Sei. Technol. 1083, 17, 753-757
Formaldehyde Release Rate Coefficients from Selected Consumer Products John A. Pickrell," Brian V. Mokler,t Larry C. Grlffls,s and Charles H. Hobbs
Inhalation Toxicology Research Institute, Lovelace Biomedical and Environmental Research Institute, Albuquerque, New Mexico 87185
Amblka Bathlja U.S. Consumer Product Safety Commission, Washington, DC 20201
Many consumer products release formaldehyde into the atmosphere in varying concentrations. A modification of the Japanese Industrial Standard (JIS)desiccator test was used to measure formaldehyde release after conditioning for 46 samples from six different types of consumer products (pressed wood products, clothes, insulation, paper, fabric, and carpet). Release rate coefficients were calculated per unit mass (pg g-l dayT1)and surface area (pg mT2day-l) for each product. The latter coefficient was used to rank the products. The eight highest release coefficients were from pressed wood products. More than half (24) of the products had release coefficients that were less than or equal to 100 pg of formaldehyde released (m2of product surface area)-l day-l. Individual samples from five of the six types of products were represented in this class. The fraction of total extractable formaldehyde released each day under JIS desiccator conditions at loading of 21 m2/m3 was calculated. Wood products and carpets released 1-4% of total extractable formaldehyde per day while fiberglass insulation released -10% per day under the conditions of this 2-day test procedure.
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Introduction The widespread use of products containing formaldehyde-based resins has led to the observation that many of these products release formaldehyde, leading to consumer annoyance and health-related complaints. Formaldehyde levels in houses and trailers have been measured in many cases and have been associated with various symptoms. The most common symptoms include irritation of eyes and upper respiratory tract (1-4). Formaldehyde has produced nasal carcinomas in mice and rats following prolonged exposure to 14.1 (mice and rats) and 5.6 ppm (rats) (1,5-7). These findings have led to an intensified concern with various consumer products that release formaldehyde into the indoor environment. The Japanese Industrial Standard (JIS) desiccator procedure is widely used to measure formaldehyde release coefficients at 100% relative humidity (RH) (8-14). Analysis of consumer products in equilibrium with 100O RH by the JIS desiccator procedure has been widely accepted as a way of ranking relative release rate coefficients from different products (8, 11, 12). Formaldehyde is extremely soluble in water (40 g/100 mL of water a t 20 "C) (8). Thus, water content of a product and fluctuations in the content could influence the formaldehyde release by various products. Because others (2,8,15,16) have reported that any change in water content of the product may alter formaldehyde release over a short-term period, it is important that the water content of the product be close to or at equilibrium with the RH of the test atmosphere.
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t Present address: Small Particle Technology, Albuquerque, NM
87111.
*
Present address: Chevron Environmental Health Center, Richmond, CA 94802. 0013-936X/83/0917-0753$01 S O / O
Table I. Samples Analyzed by the Modified JIS Desiccator Procedure
general types of samples
no. of different samples analyzed
pressed wood products new unwashed clothes insulation products paper products fabric carpet
12 4 6 3 14 7
Little systematic information is available concerning the amounts of formaldehyde released by various consumer products. This research was directed toward measuring formaldehyde release rates of various consumer products and providing a ranking by product type. We report relative release coefficients of formaldehyde from 46 consumer products including pressed wood products, clothes, insulation products, paper products, and fabrics and carpets. The percent of total extractable formaldehyde released per day was also determined for selected products.
Methods Forty-six different brands or lots of consumer products of six different general types were analyzed in this study. All products were collected and provided by the Consumer Product Safety Commission with the exception of two wood products. All products were purchased from commercial sources. The time of manufacture relative to purchase was not known. After purchase, samples were encased in plastic wrap until conditioning to minimize release of formaldehyde. One sample each of particle board and interior plywood was obtained locally and is so identified. Table I indicates the number and type of samples analyzed. Each of these products was conditioned at room temperature, and -100% RH until a nearly constant weight was obtained (weight gain / chamber volume (m3)]in a -9-L desiccator (8,17) (Figure 1). Lateral surface area was calculated by using outside dimensions. The surface area on both sides and lateral faces was used in the loading calculations. The volume of six pieces of wood products tested was > clothes insulation products paper products > fabric > carpet. Although it is possible that the ranking might have changed for some products with similar release rates, it is necessary for the product not to be gaining or losing significant amounts of water (>0.9/day) so that measured release rate will reflect
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the true release rate as closely as possible. Considering the surface area of each type of product likely to be present and the relative release rate coefficients, pressed wood products appear to have the greatest potential for formaldehyde release in a house. Exterior plywoods released very little formaldehyde, possibly because of the use of phenol-formaldehyde instead of urea-formaldehyde resin. Urea-formaldehyde resins hydrolyze slowly in continuous contact with moisture (8). Phenol-formaldehyde resins have a different chemical structure. They lack the chemical features which allow urea-formaldehyde to be hydrolyzed (8,20).The degree to which a second product with a lower release of formaldehyde might reduce the high formaldehyde release of particle board, when they are in combination, is an unresolved question. Release rate coefficients determined in this report for a variety of products are only one way of assessing the relative potential for release of formaldehyde from these products. The release rate coefficient based on surface area is a more realistic measure of potential release than is one based on weight. In this report, samples were measured at loadings of 21 m2 surface area/m3 chamber volume loading. Values of greater than fivefold higher release of formaldehyde were measured for particle board and plywood a t lower loadings of 1.5-1.8 m2 of surface area/m3 of chamber volume (16). The degree to which the ranking in this report would change under loading conditions more like the lower conditions typically present in houses and mobile homes should be investigated in the future. Total extractable formaldehyde as measured by the perforator procedure (8) provided an interesting adjunct to the measurement of formaldehyde release rate coefficients. Although measured only once for each product, it provided an estimate of the total amount of formaldehyde which is available for release at the time of extraction. Total extractable formaldehyde was correlated with formaldehyde release coefficients measured at 1.5-1.8 m2 of product surface area/ms of chamber volume loading in a desiccator (r2 = 0.96; p < 0.02) (16). No such relationship was apparent in this study between total extractable formaldehyde and the fraction that was released per day. Under the conditions of testing used in this study, insulation released a higher fraction of its extractable formaldehyde during the period of testing than did either wood or carpet products (Table 111). Also, the fraction of total extractable formaldehyde released per day a t 21 m2 of product surface area/m3 of chamber volume loading was higher for interior plywood than for particle board or carpet (Table 111). The mechanism for this release of different fractions of total extractable formaldehyde in different products is poorly understood. However, it may relate to differing total surface area to mass ratios of these products as compared to the lateral surface area used for these calculations. In regard to total surface area, glass fiber insulation would be higher than wood products or carpet. Likewise, lateral surface area of insulation products was probably much less than the available surface area in this product. Alternatively, this difference may relate to the water content of the product (very low in insulation relative to carpet or wood products). Since formaldehyde moves to the water phase of a wood-water-formaldehyde mixture (21),insulation may have a higher equilibrium pressure for formaldehyde relative to its total extractable formaldehyde than wood producta and release a higher fraction of its extractable formaldehyde. A third alternative is that formaldehyde and wood may interact within the process of release. 756
Envlron. Sci. Technol., Vol. 17, No. 12, 1983
Although both carpet and particle board release only a small fraction of their extractable formaldehyde, the extractable formaldehyde from particle board was -20-100 times higher than that of carpet (considered to be negligible). Moreover, particle board can release 225% of its extractable formaldehyde at this initial rate (17) over an -40-day time period. On the other hand, insulation released 10% of its total extractable formaldehyde during 1 day of measurement. These data and interpretations point the way toward the type of information needed for understanding formaldehyde release profiles. An initial concern would be with measured room levels of formaldehyde. The information required to convert measured release of formaldehyde in small static chambers (desiccators) to room levels of formaldehyde should be collected. This type of information should be collected in a well-designed dynamic chamber system over time, so that release measurements may be made in a system with air movement similar to that of a dwelling which would aid in converting formaldehyde release to room levels.
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Acknowledgments The technical assistance of Tina Shifani, the illustrative assistance of Emerson E. Goff, and the scientific and editorial review of Rogene F. Henderson, Ray L. Hanson, Alan R. Dahl, and other members of the ITRI staff are gratefully acknowledged. Registry No. Formaldehyde, 50-00-0.
Literature Cited (1) Blackwell, M.; Kang, H.; Thomas, A,; Infante, P. Am. Ind. Hyg. ASSOC.J. 1981, 42 (7), A34-A46. (2) Committee on Toxicology “Formaldehyde and Its Health Effects”; prepared for Consumer Product Safety Commission by National Academy Sciences, March 1980. (3) Schuck, E. A.; Stephens, E. R.; Middleton, J. T. Arch. Enuiron. Health 1966, 13, 570-575. (4) Olsen, J. H.; Dossing, - M. Am. Ind. Hyg. Assoc. J. 1982,43 (5), 366-370. (5) Swenberg, J. A,; Kerns, W. D.; Mitchell, R. I.; Gralla, E. J.; Pavkov, K. L. Cancer Res. 1980,40, 3398-3401. (6) Albert,R.; Sellakumar, A.; Laskin, S.; Kuschner, M.; Nelson, N.; Snyder, C. A. JNCI, J.Natl. Cancer Inst. 1982,68 (4), 597-603. (7) Committee on Indoor Pollutants “Indoor Pollutants”; National Research Council, National Academy Press: Washington, DC, 1981. (8) Meyer, B. “Urea Formaldehyde Resins”; Addison-Wesley: Reading, MA, 1979; p 423. (9) Meyer, B.; Koshlap, K. Molecular and Materials Research Division, Lawrence Berkeley Laboratory, University of California, Berkeley, CA 1981, LBL Report 12570 (DRAFT). (10) Myers, G. E.; Nagoka, M. Symposium on Wood Adhesives-Research, Applications and Needs, Forest Product Laboratories, Madison, WI, Sept 1980. (11) Myers, G. E.; Nagoka, M. Wood Sci. 1981,13 (3), 14C-150. (12) Sundin, B., presented at The International Particle Board Series Symposium No. 16, Washington State University, Pullman, WA, March 30-April 1, 1982. (13) Fujii, S.; Suzuki, T.; Koyagashiro, S. Kenzai Shiken Joho, Transl., 1973, 9 (3), 10-14. (14) Griffis, L.; Pickrell, J. A. Enuiron. Int. 1983, 9, 3-7. (15) Andersen, I.; Lundquist, G. R.; Molhave, L. Atrnos. Enuiron. 1975, 9, 121-127. (16) Moschondreas, D. J.; Rector, H. E. National Technical Information Service, 1981, Technical Report LBL-12590, EEB-Vent El-12. (17) Pickrell, J. A.; Griffis, L. C.; Hobbs, C. H. “Release of Formaldehyde from Various Consumer Products”; final report to the Consumer Product Safety Commission, Lovelace Inhalation Technology Research Institute, Na-
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(20) Roberts, J. D.; Caeerio, M. C. “Basic Principles of Organic Chemistry”; W. A. Benjamin: New York, NY, 1965; pp
tional Technical Information Service, 1982, LMF-93. (18) Miksch, R. R.; Anthon, D. W.; Fanning, L. Z.; Hollowell, C. D. Revzan, K.; Glanville, J. Anal. Chem. 1981, 53, 2118-2123. (19) Singh, J.; Walcott, R.; St. Pierre, C.; Ferrel, T.; Garrison,
S.; Gramp, G.; Groah, W. “Evaluation of the Relationship Between Formaldehyde Emissions from Particle Board Mobile Home Decking and Hardwood Plywood Wall Paneling as Determined by Product Test Methods and Formaldehyde Levels in Experimental Mobile Homes”; technical report, U.S.Department Housing and Urban Development, Office of Policy Development and Research, Division of Energy, Building Technology and Standards, March 1982.
1083-11 15. (21) Johns, W. E.; Jahan-Latiban, A. Wood Fiber 1980, 12, 144-152.
Received for review December 20,1982. Accepted June 29,1983. Research performed for the Consumer Product Safety Commission under Interagency Agreement CPSC-IAG-801463 under U S . Department of Energy Contract DE-AC04-76EV01013. The views expressed in this paper are those of the authors and do not necessarily represent those of The Consumer Product Safety Commision or the U S . Department of Energy.
NOTES Emissions of Ammonia and Amines from Vehicles on the Road William R. Plerson” and Wanda W. Brachaczek
Research Staff, Ford Motor Company, Dearborn, Michigan 48 121 Experiments were conducted in the Allegheny Mountain Tunnel of the Pennsylvania Turnpike in 1981 to evaluate ammonia emissions from gasoline-powered vehicles and heavy-duty diesel vehicles in highway operation. Emission of NH3 and aerosol NH4+from gasoline-powered vehicles was below our detection limit, i.e., K0.28 mmol/km. Emission of NH3 + NH4+ from diesel trucks was 1.45 f 0.35 mmol/km or, stated as NH3, 25 f 6 mg/km (possibly including significant amounts from the livestock hauled by many of these trucks). Dimethyl- and diethylamines were sought at the same time because the two amines are of interest as possible atmospheric precursors of dimethyland diethylnitrosamines which are animal carcinogens that have been reported in air principally in industrial areas. No amines were found; methylamine, ethylamine, dimethylamine, diethylamine, and trimethylamine were all below the detection limits of 0.04-0.3 mg/km (depending on the compound) for gasoline-powered vehicles and 0.08-0.7 mg/km for heavy-duty diesels. Introduction From time to time questions are raised about nitrosamines and nitramines in the environment. These compounds are carcinogenic to animals and hence are suspected human carcinogens (1). Nitrosamines have been reported in ambient air (2-4), especially near industrial sources. Evidently the amount of nitrosamines emitted in vehicle exhaust is inconsequential (5-7). Nitrosamines have been sought in diesel crankcase blowby emissions, with positive (8),negative (6),and equivocal (9) results. The upper limits on the amounts reported are many orders of magnitude too small to account for the nitrosamines reported (2-4) in air samples. The question arises, then, whether dialkylamines are emitted by motor vehicles at rates sufficient to form significant amounts of nitrosamines by reactions in the atmosphere with traces of nitrous acid or even concurrently emitted nitrogen oxides. The answer is definitely no, in the case of gasoline-powered automo0013-936X/83/0917-0757$01.50/0
biles, on the basis of chassis-dynamometerexperiments (5, 10-17). The work reported herein shows that the same holds in an actual on-road setting and for both gasolinepowered and heavy-duty diesel vehicles. The method employed in this study for amine measurements also provided data on ammonia emissions. Such data are of interest from the standpoint of emission inventories and also because ammonia is important in atmospheric chemistry. As a pollutant, ammonia from automotive sources evidently is not significant (18, 19). Ammonia emissions data are available from chassis dynamometer studies (5, 12-1 7,20-26), but heretofore not from roadway studies. Experimental Procedures Amines and ammonia together with their salts were measured in the Allegheny Mountain Tunnel of the Pennsylvania Turnpike, July 22-30,1981. Air was sampled at 3 L/min (known within a few percent) through impingers containing 0.01 N H2S04 (40 mL) to trap the gas-phase amines and ammonia. Upstream of each impinger was a Teflon membrane filter (Ghia “Zefluor”) of 0.2-pm nominal pore diameter to remove particulate matter including ammonium salts, alkylammonium salts, and any amines adsorbed to the aerosol particles. Each filter was immersed, immediately after sampling, in 0.01 N H2S04 (10 mL). The H2S04impinger and filter solutions were analyzed for NH4+and alkylammonium ions by an ion chromatographic procedure patterned after one described elsewhere (27) and also for amines by gas chromatography with a nitrogen-sensitive detector. The gas chromatographic method (28) employs a 1.8 m X 2 mm glass column packed with 4 % Carbowax 20M/0.8% KOH on Carbopak B, the silanized glass wool having been removed from the front of the column in order to prevent adsorptive losses of the amines and to prevent a “memory” effect. Before analysis, the sample solutions were placed in small vials sealed with Teflon-coated septa and then made alkaline by injecting 1N KOH into the vials through
0 1983 American Chemical Society
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