On January 21, 2016, the National Institute for Occupational Safety and Health (NIOSH) announced the availability of a draft NIOSH Current Intelligence Bulletin: Health Effects of Occupational Exposure to Silver Nanomaterials. The draft Current Intelligence Bulletin (CIB) includes a review and assessment of the currently available scientific literature on the toxicological effects of exposure to silver nanoparticles in experimental animal and cellular systems, and on the occupational exposures to silver dust and fume and the associated health effects. According to the draft CIB, “[a]lthough the experimental animal and cellular studies are useful for showing potential risks from exposure to silver nanomaterials, NIOSH considers the currently available data to be too limited to develop a REL for silver that is specific to particle size.” Instead, NIOSH recommends that effective risk management control practices be implemented so that worker exposures to silver nanomaterials do not exceed the NIOSH recommended exposure limit (REL) of ten micrograms per cubic meter (μg/m3) (eight-hour time-weighted average) for silver metal dust, fume, and soluble compounds, measured as a total airborne mass concentration. NIOSH “recommends additional prudent measures including conducting workplace exposure and hazard assessments and medical surveillance of workers potentially exposed to silver nanomaterials.” The draft CIB provides recommendations for the safe handling of silver nanoparticles, and proposes research needs to fill important data gaps in the current scientific literature on the potential adverse health effects of occupational exposure to silver nanoparticles. NIOSH seeks public comments on the draft CIB, and will hold a public meeting to discuss the CIB on March 23, 2016. Comments are due March 21, 2016.
The Federal Register notice states that special emphasis will be placed on discussion of the following:
- Whether the health hazard identification, risk estimation, and discussion of health effects of silver and silver nanomaterials are a reasonable reflection of the current understanding of the scientific literature;
- Workplaces and occupations where exposure to silver and silver nanomaterials may occur; and studies on health effects associated with occupational exposure to silver dust and fume;
- Current strategies for controlling or preventing exposure to silver and silver nanomaterials (g., engineering controls, work practices, personal protective equipment);
- Current exposure measurement methods and challenges in measuring workplace exposures to silver nanomaterials; and
- Areas for future collaborative efforts (g., research, communication, development of exposure measurement and control strategies).
During the public meeting, NIOSH will allow commenters to provide oral comments on the draft CIB, to inform NIOSH about additional relevant data or information, and to ask questions on the draft CIB and NIOSH recommendations. The Federal Register notice states that the forum will include scientists and representatives from various government agencies, industry, labor, and other stakeholders, and is open to the public. The meeting will be open to a limited number of participants through a conference call phone number and will be webcast live on the Internet. Due to the limited spaces, notification of intent to attend the meeting must be made no later than March 9, 2016. NIOSH states that it will give priority for attendance to those providing oral comments. Other requests to attend the meeting will then be accommodated on a first-come, first-served basis.