Dust Study practices

Farfel, M. R., Orlova, A. O., Lees, P. S. J., Rohde, C., Ashley, P. J., Chisolm, J. J., Jr. (2003). A study of urban housing demolitions as sources of lead in Ambient dust Demolition practices and exterior dust fall. Environmental Health Perspectives, 111. 

A major purpose of the Dust Study was to assess the proposed work practices. A statistically valid sample of housing at the national level is not needed to assess the work practices. If anything, the Dust Study is conservative with respect to the age of housing because it studied older houses and therefore is appropriate for assessing the effectiveness of the work practices. 

In particular, the Dust Study found that renovation activities involving power planing and high temperature heat gun resulted in higher post-job renovation dust lead levels than activities using other practices. The geometric mean post-work, precleaning... 

Based on the results of the Dust Study and in response to the voluminous persuasive public comments, this final rule prohibits or restricts the use of the following practices during renovation, repair, and painting activities that are subject to the work practice requirements of this rule ... 

The Dust Study, which is described elsewhere in the preamble, assessed the proposed work practices. As one component of the proposed work practices, the cleaning verification was evaluated in the Dust Study. It should be noted that the Dust Study was not designed specifically to evaluate the cleaning verification in isolation of the rest of the work practices. Unlike the earlier Disposable Cleaning Cloth Study that was intended to test the effectiveness of the use of the white glove test in isolation, the Dust Study was meant to evaluate the effectiveness of the proposed work practices, including cleaning verification. 

Cleaning verification, when used apart from the other work practices, is not as reliable a test for determining whether the hazard standard has been achieved as clearance testing. However, the Dust Study supports the validity of cleaning verification as an effective component of the work practices. The cleaning and feedback aspects of cleaning verification are important to its contribution to the effectiveness of the work practices. 

Based on a review of the Dust Study and the Disposable Cleaning Cloth Study, EPA concluded that if the practices prohibited in this final rule are avoided and the required work practices are followed, then cleaning verification is an effective component of the work practices. EPA believes that the suite of work practices as a whole are effective at addressing the lead-paint dust that is generated during renovation, repair, and painting preparation activities. 

The Environmental Protection Agency received comments prior to the 2007 reqnest for comments on the proposed work practices in light of the Dnst Stndy. Those pre-Dust Study comments are summarized in the following paragraphs. 

EPA disagrees with these commenters. The Dust Study did provide a real-world practical setting in which to assess the use of cleaning verification. Local renovation contractors performed actual renovations for each experiment in the study. The contractors performed cleaning verification on floors of wood, vinyl, or tile, in good, fair, or poor condition. The Dust Study used the protocols that were consistent with those in the 2006 Proposal. 

Finely divided aluminium powder or dust forms highly explosive dispersions in air [1], and all aspects of prevention of aluminium dust explosions are covered in 2 recent US National Fire Codes [2], The effects on ignition properties of impurities introduced by recycled metal used to prepare dust were studied [3], Pyrophoricity is eliminated by surface coating aluminium powder with polystyrene [4], Explosion hazards involved in arc and flame spraying of the powder are analysed and discussed [5], and the effect of surface oxide layers on flammability was studied [6], The causes of a severe explosion in 1983 in a plant producing fine aluminium powder are analysed, and improvements in safety practices discussed... 

Lower limits of explosibility of several organic dusts were determined and found to be in general agreement with estimated values [24], Probabalistic aspects of occurrence of dust explosions were studied experimentally with lycopodium powder in relation to dust and hot surface (or dust) temperature. The probability of explosion increases with dust concentration, then falls off, due to the ballast effect of unbumt dust. Probability also increases continuously with the temperature of the hot surface and/or dust particles. Application of the results to practical plant... 

The American Textile Industry Involvement with cotton dust as a workplace hazard began over ten years ago with Industry studies to determine whether the Industry had such an Illness problem. Then followed major dust removal and ventlllatlon efforts. The Industry developed a work practices and medical surveillance program which was presented to OSHA. 

Atmospheric effects of large-scale TNT expins have also been studied in depth both practically and theoretically. Factors considered include pressure and impulse effects, decay characteristics and travel and duration times, all as a function of distance, and for both free-field and reflection situations (Refs 3,9,15,16, 17,24,32, 33,34,35,36,44, 53,75,76,115 116). A distinction is made between the blast area dose to the source, comprising air and the products of expln, and that farther away involving air only (Ref 53). Double-burst conditions (fireball and shock wave interaction, and torus formation) have been studied (Ref 149), as have also the dynamics of dust formation and motion (Refs 25,26 117). Performance tests were run on a naval blast valve (Ref 92), and on aircraft wing panels (Ref 4)... 

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