Allotropes Some elements exist in several different structural forms, called allotropes. Each allotrope has different physical properties. For more information on the Visual Elements image see the Uses and properties section below. Group A vertical column in the periodic table.
Cosmogenic nuclide dating
Revising the Beryllium Standard for General Industry
OSHA has issued a final rule, published in the August 9 Federal Register , to extend the compliance date for specific ancillary requirements of the general industry beryllium standard to December 12, The extension affects provisions for methods of compliance, beryllium work areas, regulated areas, personal protective clothing and equipment, hygiene facilities and practices, housekeeping, communication of hazards, and recordkeeping. This compliance date extension does not affect the compliance dates for other requirements of the general industry beryllium standard. OSHA began enforcing the new permissible exposure limits for general industry, construction, and shipyards, and the general industry provisions for exposure assessment, respiratory protection, medical surveillance, and medical removal on May 11, Those requirements are unaffected by this rule. Any provisions for which the standard already establishes compliance dates in change rooms and showers or engineering controls are also unaffected by this rule. The Final Rule is available here.
Compliance Date for Certain Beryllium Provisions Extended
The use of cosmogenic beryllium-7 7Be as a soil and sediment tracer relies upon a number of important assumptions which to date have not been fully underpinned by supporting data. As a catchment management tool 7Be offers unique potential to assess the effects of recent land use or climate change but further research is required to provide confidence in key data and elucidate sources of uncertainty. Through a range of laboratory and field studies, this thesis aims to explore knowledge gaps relating to i the temporal and spatial dynamics of 7Be activity in rainfall which has importance in the context of estimating fallout input during erosion studies ii adsorption behaviour in soils which is of critical importance when considering tracer stability at the field and catchment-scale and iii the reliability of erosion estimates using 7Be inventories at the slope-scale to address the current lack of model validation. Findings showed temporal and spatial variability of 7Be fallout emphasising the need for regular site-specific sampling to determine fallout flux during erosion studies.
The final rule, published in the Aug. The first has a compliance date of March 11, ; the latter is slated to go into effect on March 10, OSHA is enforcing the permissible exposure limit of 0. Beryllium is a strong, lightweight metal used in electronics and the defense industry, among others. Overexposure can cause serious health risks, including incurable chronic beryllium disease and lung cancer.