EPA tightens safety provisions for nanotech workers

On Wednesday, June 24, EPA established a new federal rule that requires nanotechnology workers exposed to carbon nanotubes to use respirators and wear protective clothing. The new direct final rule will go into effect Aug. 24, 2009.

Under the new rule, EPA designated 23 chemical substances as a “significant new use” under a provision of the Toxic Substances Control Act of 1976. The rule requires companies manufacturing, importing or processing any of the 23 substances to notify EPA at least 90 days before commencing the activity.

The Arlington, VA-based American Chemistry Council issued a press release calling the agency’s provisions in the rule “a reasonable approach” as additional research is conducted on potential health and environmental impacts of nanotechnology.

What is Nanotechnology?

Nanotechnology is somewhat loosely defined, although in general terms it covers engineered structures, devices and systems that have a length scale of 1 – 100 nanometers. At these length scales, materials begin to exhibit unique properties that affect physical, chemical and biological behavior. Researching, developing and utilizing these properties is at the heart of the new technology. The use of the term “nanotechnology” can be misleading since it is not a single technology or scientific discipline. Rather it is a multidisciplinary grouping of physical, chemical, biological, engineering, and electronic, processes, materials, applications and concepts in which the defining characteristic is one of size.

Background

The past decade has seen intense interest in developing technologies based on the unique behavior of nanometer-scale (nanoscale) structures, devices and systems, leading to the rapidly expanding and highly diverse field of nanotechnology.

Although many nanotechnologies are still in the pre-competitive stage, nanoscale materials are increasingly being used in optoelectronic, electronic, magnetic, medical imaging, drug delivery, cosmetic, catalytic and materials applications. Between 1997 and 2003, worldwide government investment in the field rose from $432 million a year to just under $3 billion a year, and the global impact of nanotechnology-related products is predicted to exceed $1 trillion by 20152.

The National Institute of Occupational Health (NIOSH) is unaware of any comprehensive statistics on the number of people in the U.S. employed in all occupations or industries in which they might be exposed to engineered, nano-diameter particles in the production or the use of nanomaterials. Perhaps because of the relative newness of the nanotechnology industry, there appear to be no current, comprehensive data from official survey sources, such as the U.S. Bureau of Labor Statistics (BLS).

Occupational Health Risks

Occupational health risks associated with manufacturing and using nanomaterials are not yet clearly understood. The rapid growth of nanotechnology is leading to the development of new materials, devices and processes that lie far beyond our current understanding of environmental and human impact. Many nanomaterials and devices are formed from nanometer-scale particles (nanoparticles) that are initially produced as aerosols or colloidal suspensions. Exposure to these materials during manufacturing and use may occur through inhalation, dermal contact and ingestion. Minimal information is currently available on dominant exposure routes, potential exposure levels and material toxicity. What information does exist comes primarily from the study of ultrafine particles (typically defined as particles smaller than 100 nanometers).

Studies have indicated that low solubility ultrafine particles are more toxic than larger particles on a mass for mass basis. There are strong indications that particle surface area and surface chemistry are primarily responsible for observed responses in cell cultures and animals. There are also indications that ultrafine particles can penetrate through the skin, or translocate from the respiratory system to other organs. Research is continuing to understand how these unique modes of biological interaction may lead to specific health effects.

Workers within nanotechnology-related industries have the potential to be exposed to uniquely engineered materials with novel sizes, shapes and physical and chemical properties, at levels far exceeding ambient concentrations. To understand the impact of these exposures on health, and how best to devise appropriate exposure monitoring and control strategies, much research is still needed. Until a clearer picture emerges, the limited evidence available would suggest caution when potential exposures to nanoparticles may occur.

TEES Requirements for Working Safely with Nanotechnology

The Engineering Program, TEES and the Look College of Engineering have established guidelines for reducing risk and working safely with nanoscale materials in research and academic work. The full guideline is available on our Engineering SafetyNet web site at http://engineering.tamu.edu/safety/, under “Guidelines.” Researchers planning to use nanoscale materials must complete a Project Safety Analysis (PSA) incorporating these nanotechnology safety guidelines.

SUMMARY: Reasonable Control Strategies for Working with Nanotechnology

Strategies to control potentially harmful exposure to nanoparticles will include:

• Total enclosure of the process
• Storage of all nano-materials in total enclosure
• Local exhaust ventilation, with HEPA filtration
• General ventilation
• Limitation of numbers of workers and exclusion of at risk individuals
• Reduction in periods of exposure, via SOP’s and personnel training
• Regular cleaning of wall, floor and other surfaces; documented cleaning schedule
• Use of appropriate personal protective equipment
• Prohibition of eating and drinking in laboratories and controlled areas
• Transport of nano-materials within secondary containment device
• Immediate cleanup of all spills & discharges
• Use free, unfixed nanoscale materials within an enclosure, such as a rated hood or glovebox where the exhaust air is filtered to collect the nanoparticles before discharge.
• Collection of all nanoparticle waste materials for disposal in compliance with the TAMU Hazardous Waste Management Plan.

Resources for Further Information

i. Nanotechnology at NIOSH

http://www.cdc.gov/niosh/topics/nanotech/

ii. Guidelines for Working Safely with Nanomaterials in Engineering Research

http://engineering.tamu.edu/safety/, under “Guidelines”

Contact:

D. C. Breeding, PhD, RPE, CSP, CHMM

Manager, Office of Engineering Safety

979-845-4986 or <Safety@tees.tamus.edu>