Evolution of beryllium safety standards over the last 70 years and challenges ahead

Abstract

Beryllium (Be), its alloys, and ceramics are widely used in high-tech applications such as electronics, space, atomic energy, and other day-to-day items of use. Initially, Be-based phosphors such as ZnBeSiO4 were being used in the lamp industry during the 1930s onward but were soon abandoned due to lung-related diseases and deaths of workers in the phosphor industry which was attributed to the highly toxic nature of Be. Typical effects associated with Be inhalation are chronic and acute Be diseases (CBD and ABD) and the main target organ being affected is the lung although effects on other human body organs are also well documented. Such diseases were observed not only in occupational workers handling Be but also in the members of the public residing in the neighborhood of Be manufacturing and processing facilities, especially in the USA. The CBD in occupational workers may depend on many factors such as individual's sensitivity to Be, amount of Be exposure, nature of Be compound, and types of Be operations and processes being performed. All this led to safety concerns about the toxicity of Be and recommendations regarding Be air concentration in the workplace and public environment were issued by the Department of Energy, USA in 1949 as occupational exposure limit (OEL)/threshold limit values (TLVs) which were 2.0 μg/m3 and 0.01 μg/m3 for occupational Be workers and public environment, respectively. It is worth to mention that these recommendations were adopted by various countries and organizations either as it is or with small changes. Later, different organizations recommended changes in the value of TLV for occupational workplaces, but such changes were never adopted as they were lacking sound epidemiological basis. The OEL/TLV of 2.0 μg/m3 continued for nearly 70 years until Occupational Safety and Health Administration (OSHA) in 2017 reduced the Be air concentration (BeAir-Conc) limit for occupational workers to 0.20 μg/m3 as the value of 2.00 μg/m3 was inadequate to protect occupational workers from CBD. This is a major change in the Be-related safety standards recommended recently and is/being adopted by many countries. The present article provides details about the evolution of Be safety standards over the last 70 years, the notion behind the recent revision of Be permissible exposure limit (PEL) value from 2.0 μg/m3 to 0.20 μg/m3 by OSHA and the associated safety challenges ahead. The information from literature about Be safety and related safety standards adopted in India is also given. The article also provides details about TLVs for BeAir-Conc being followed in various countries in the world and various challenges for the implementation of a revised PEL value of 0.20 μg/m3 as suggested by OSHA i.e., reduction in PEL value by a factor of 10 or recommendation of revised TLV of 0.05 μg/m3 by American Conference of Governmental Industrial Hygienists as compared to the previous value of 2.0 μg/m3. In view of different notations and limits for BeAir-Conc recommended by various agencies and limited information about Be safety-related details, all relevant information regarding Be safety along with the evolution of Be safety standards over the last 70 years is included in the present article. This is an important issue for the safety of individual's at occupational workplaces as well as for environmental safety and its compilation was highly needed for providing comprehensive information on Be safety from the inception of standards to till today.