Document ppjQjwZygEB5Lod5R043BBa87

Industrial Hygiene Digest December, 1967 1184 Absorption and Translocation of Dieldrin by Forage Crops. W. B. Wheeler, et al. J. Agr. Food Chem. J_5, 231 -234 (March-April, 1967). Quantitative relationships ha,re been established among various levels of dieldrin in sand and in soil and the concentrations found in the aerial portion of wheat, corn, orchard grass, and alfalfa grown in these substrates under controlled environmental conditions. Plants grown in sand contained levels of dieldrin 2 to 6 times higher than plants grown in soil. A second cutting of the same wheat plants revealed a higher accumulation of the insecticide than the first cutting. Finally, the general distribution of dieldrin within young wheat plants was determined by chemical analysis. Plants used for forage were capable of absorbing and translocating dieldrin from the substrates in which they were grown. There are 12 references. -- Authors' abst. cond. , Public Health Eng. Absts. 1185 Los Angeles Rule 66 and Exempt Solvents. E. C. Larson and H. E. Sipple. J. Paint Technol, 39, 258-266 (May, 1967). Rule 66 adopted by Los Angeles County Air Pollution Control District on July 28, 1966, is designed to control emission of photochemically reactive volatile organic substances into the atmosphere. Although both are important and regulated, emphasis is placed on the type of compound rather than quantity of the emission. A limited amount of non-exempt solvents can be used, but it will be expedient to utilize exempt solvents wherever possible. According to the Rule an exempt solvent can contain a maximum of 20% of photochemically reactive com pounds consisting of: (1) 5% v maximum olefinic or cycloolefinic unsaturation: (2) 8% v maxi mum of aromatics having eight or more carbon atoms to the molecule except ethylbenzene; or (3) 20% v of a combination of toluene, ethylebenzene, ketones having branched hydrocarbon structures or trichloroethylene. Thus, primary attention is focused on aromatic content of paint solvents. Exempt mineral spirits and VM and P naphthas will contain less than 20% of complying aromatics. High solvency naphthenic base stocks will help offset the solvency of the displaced aromatics. These exempt solvents will be entirely adequate for long oil alkyds and many medium oil alkyds. But where greater solvency is needed, as in short oil alkyds, vinyls, expoxies, and the like, oxygenated compounds such as alcohols, ketones, and esters must be incorporated in the solvents. Rule 66 is already in effect for Installations of new equipment. Existing operations will come under control in three stages beginning on July 1, 1967, for the large consumer. Finally, the rule involves the application of both industrial and architectural coatings. -- Authors' summary, APCA Absts. f INDUSTRIAL DUSTS ~~| 1186 Removing Solid and Mist Particles From Exhaust Gases. N. Morash, M. Krouse, and W. P. Vosseller. Chem. Eng. Progr. 63, 70-74 (March, 1967). This article reports the results obtained when an irrigated, thin, felted fiber filter is used to remove a mixture of fine titanium dioxide pigmentary particles and sulfuric acid mist particles from the exhaust gases of pigment calciners. Four references are given. -Authors' abst., Public Health Eng. Absts. 1187 Primer on Fabric Dust Collectors. H. E. Friedrich. Air Eng. 26-31 (May, 1967). This look at the types of fabric collectors available for air pollution control and product recovery should indicate that, although they are by no means capable of handling all air pollution problems, they can solve many dust collection problems where properly applied. All cleanable industrial fabric filters are capable of giving very high collection efficiency (99. 9% by weight) and can operate over a range of airflow resistances depending on air-to- cloth ratio. For equal collection efficiency and resistance, commercial units may vary in size, operating, and maintenance requirements, but generally they will cost alike on a totally owned basis and will have closely similar power requirements. -- APCA Absts. 16. 03122723