A
new report from the U.S. Environmental Protection Agency presents a
case study of engineered nanoscale silver (nano-Ag), focusing on the
specific example of nano-Ag as possibly used in disinfectant sprays.
The
case study is organized around the comprehensive environmental
assessment (CEA) framework, which structures available information
pertaining to the product life cycle, environmental transport and fate,
exposure-dose in receptors (i.e., humans, ecological populations, and
the environment), and potential impacts in these receptors. The document
does not draw conclusions about potential risks. Instead, it is
intended to be used as part of a process to identify what is known and
unknown about nano-Ag in a selected application. In turn, the external
review draft of the document provided a starting point to identify and
prioritize possible research directions to support future assessments of
nanomaterials.
Engineered
nanoscale materials (nanomaterials) have been described as having at
least one dimension between 1 and 100 nm. They often have novel or
unique properties that can arise from their small size. Like all
technological developments, nanomaterials offer the potential for both
benefits and risks. The assessment of such risks and benefits requires
information, but given the nascent state of nanotechnology, much remains
to be learned about the characteristics and effects of nanomaterials.
The
document (“Nanomaterial Case Study: Nanoscale Silver in Disinfectant
Spray”) is intended to be used as part of a process to identify what is
known and, more importantly, what is not yet known that could be of
value in assessing the broad implications of certain nanomaterials. The
complex properties of various nanomaterials make evaluating them in the
abstract or with generalizations difficult if not impossible. Thus, this
document focuses on a specific example of nano-Ag in disinfectant spray
products.
The
case study does not represent a completed or even a preliminary
assessment of nano-Ag; rather, it and other, similar case studies
support research planning efforts for nanomaterials. The document is
organized around the comprehensive environmental assessment (CEA)
framework, which structures available information pertaining to the
product life cycle, transport, transformation and fate processes in
environmental media, exposure-dose in receptors (i.e., humans,
ecological populations, and the environment), and potential impacts in
these receptors. When information is available, it also includes other
direct and indirect ramifications of both primary and secondary
substances or stressors associated with a nanomaterial.
The
CEA approach is both a framework and a process; the external review
draft of the document supported the latter aspect, which engaged
stakeholders from diverse technical (e.g., toxicology, exposure science,
atmospheric chemistry) and sector (e.g., industry, government,
academia) backgrounds. Through a structured collective judgment method
these expert stakeholders used the document to identify and prioritize
research gaps that could inform future assessments and risk management
efforts. Some of these research gaps pertain to nano-Ag in disinfectant
spray; others to nano-Ag irrespective of its application, while still
others may apply more widely to nanomaterials in general. These and
other research gaps identified through similar applications of CEA to
nanomaterials are intended to inform ongoing research planning for
nanotechnology in the general scientific community as well as at the
EPA.
Report: Nanomaterial Case Study: Nanoscale Silver in Disinfectant Spray
Source: EPA
