Nanomaterials

Health & Safety Guidelines for Working with Nanomaterials at Cornell

Introduction

The National Institute for Occupational Safety and Health (NIOSH) is the lead federal agency for research on the occupational safety and health implications of nanomaterials. In this role, NIOSH recognizes that the research community is at the front line of creating new nanomaterials; testing their usefulness in a variety of applications, and determining their toxicological and environmental impacts. Although the risks of nanomaterials to human health and the environment are largely unknown, it is prudent to be aware of current information and recommendations for handling nanomaterials from NIOSH and other authoritative sources. The Cornell Department of Environmental Health and Safety (EHS) maintains this webpage to make health and safety information available to our faculty, staff, and students who work with engineered nanomaterials.

Definition

Nanotechnology is the engineering and manipulation of structures with dimensions ranging from 1 to 100 nanometers. These are often incorporated into a larger matrix known as a nanomaterial. In many cases, particles created at the nanoscale are found to have different chemical and physical properties than larger particles of the same material. These manufactured nanomaterials are also known as engineered nanomaterials.

NIOSH Recommendations for Nanomaterial Safety

The information below is a summary of (Click here to download the complete publication) NIOSH Publication No. 2012-147: General Safe Practices for Working with Engineered Nanomaterials in Research Laboratories.

Hazards of Nanoparticles

The characterization and potential for release of the nanomaterial is a challenge. NIOSH is conducting research of its own and summarizing the results of studies to determine when nanomaterials are likely to pose a safety and health threat to exposed workers, the general public and the environment. Different types of nanomaterials are made or used in various processes. To determine whether these nanomaterials pose a hazard, scientists must know the following:

the identity of the chemical constituents,
the shape of the nanomaterials,
the resulting physical and chemical properties of the nanomaterials, and
the concentrations of the nanomaterials in the environment

Based on these considerations, the primary health and safety concerns are:

Nanomaterial Safety: Fire, explosion and other unexpected reactions involving nanomaterials are the main safety hazards. Materials at the nanometer scale may unexpectedly become chemical catalysts and result in unanticipated reactions.
Health: Laboratory studies with animals have shown that when some types of nanoparticles are inhaled, they may reach the blood, brain, and other organs of laboratory animals. Some studies have shown adverse effects such as inflammation and fibrosis in the lungs and other organs. These studies are ongoing to better define the health impacts of nanomaterials.
Environment: There are many ongoing studies of the impact of nanomaterial releases into the general environment, whether by air or wastewater or in the handling of hazard waste. These have not progressed far enough for any regulatory authority to establish limits for these emissions. For this reason, Cornell EHS recommends disposal of all nanomaterials through our hazardous waste program.
Laboratory Safety: The processes of producing nanomaterials require the use of a variety of highly reactive materials such as concentrated mineral acids, organic solvents and strong oxidizers. Careful management of these chemicals must be an important consideration using prudent laboratory practices.

Although more research is needed to predict the effects of nanomaterial exposures in humans, sufficient information is available to provide interim recommendations and guidance about occupational exposures. NIOSH recommends a prudent approach for manufacturing and using nanomaterials in industry. Employers should take steps to minimize worker exposures until more information is available.

Controlling Personal Exposure to Nanomaterials

Several factors affect worker exposure to nanomaterials:

The concentration, duration, and frequency of exposure to nanoparticles all affect worker exposure.
In addition, the ability of nanoparticles to be easily dispersed as a dust (e.g. a powder) or an airborne spray or droplets will impact exposure of the workers.
Use of protective measures such as engineering controls (e.g. fume hoods) and personal protective equipment (e.g. gloves) can reduce worker exposure.

Job-related activities may also influence worker exposure:

Active handling of nanomaterials as powders on the benchtop pose the greatest risk for inhalation exposure; NIOSH recommends the use of HEPA filters, either in respirators or local ventilation equipment to control such powders
Tasks that generate aerosols of nanomaterials from slurries, suspensions, or solutions pose a potential for both inhalation and dermal exposure. In some cases, it has been found that nanomaterials have penetrated both gloves and skin.
Cleanup and waste disposal of nanomaterials may result in exposure if not properly handled. Maintenance and cleaning of production systems or dust collection systems may result in exposure if deposited nanoparticles are disturbed.
Machining, sanding, drilling, or other mechanical disruptions of materials containing nanomaterials may lead to aerosolization of them.

Measurement of Nanomaterials

Traditional industrial hygiene sampling methods such as airborne dust measurements have been used to measure airborne nanomaterials. However, these methods require careful interpretation. Scientists are developing more sensitive and specific sampling techniques to evaluate occupational exposures. Sampling in the workplace should include background measurements and measurements before, during, and after production or handling of these materials. These measurements can determine if emissions and possible exposures are occurring.

Exposure Controls

Elimination or Substitution to a less hazardous substance is a basic principle of occupational safety and health. Certain aspects of a process may be changed and result in a less hazardous situation to exist. Engineered Nanomaterials: Investigating substitution and modification options to reduce potential hazards is a source of information about potential substitutions to improve nanomaterial safety.
Engineering Controls should be used to reduce worker exposures to nanomaterials. They have been designed to reduce exposures to other particles of similar size. Examples include source enclosure (isolating the generation source from the worker) and local exhaust ventilation systems. Exhaust ventilation systems that use high-efficiency particulate air (HEPA) filters are very effective in removing nanomaterials. The following table is provided by NIOSH to make recommendations of installing control measures depending on the nanomaterial used in specific activities.
Administrative Controls include operational procedures to limit exposure by reducing the time the employee is handling the material, specifying good housekeeping and other good work practices, training employees, and implementing proper labeling and storage of materials.
Personal Protective Equipment, such as respirators and appropriate gloves and coveralls, should be considered if engineering and administrative controls cannot control exposures. The decision to use respirators should be based on professional judgment and an assessment of worker exposures and the health risks they pose.

Nanoparticles- Handle with care... even with gloves!

Criteria for exposure potential and recommended minimum controls
State of the nanomaterial	Employee activity	Potential exposure source	Recommended engineering controls
Bound or fixed nanostructures (polymer matrix)	Mechanical grinding, alloying, etching, lithography, erosion, mechanical abrasion, grinding, sanding, drilling, heating, cooling	Nanomaterials may be released during grinding, drilling, and sanding. Heating or cooling may damage the matrix, allowing release of nanomaterial.	Local exhaust ventilation Laboratory chemical hood with HEPA-filtered exhaust HEPA-filtered exhausted enclosure (glovebox) Biological safety cabinet class II type A1, A2, vented via thimble connection, or B1 or B2
Liquid suspension, liquid dispersion	Synthesis methods: chemical precipitation, chemical deposition, colloidal, electrodeposition crystallization, laser ablation (in liquid) Pouring and mixing of liquid containing nanomaterials Sonication Spraying Spray drying	Exposures may result from aerosolization of nanoparticles during sonication or spraying, equipment cleaning and maintenance, spills, or product recovery (dry powders).	Laboratory chemical hood (with HEPA-filtered exhaust) HEPA-filtered exhausted enclosure (glovebox) Biological safety cabinet class II type A1, A2, vented via thimble connection, or B1 or B2
Dry dispersible nanomaterials and agglomerates	Collection of material (after synthesis), material transfers, weighing of dry powders, mixing of dry powders	Exposures may occur during any dry powder handling activity or product recovery.	Laboratory chemical hood with HEPA-filtered exhaust HEPA-filtered exhausted enclosure (glovebox) Biological safety cabinet class II, B1 or B2
Nanoaerosols and gas phase synthesis (on substrate)	Vapor deposition, vapor condensation, rapid solidification, aerosol techniques, gas phase agglomeration, inert gas condensation (flame pyrolysis, high temperature evaporation), or spraying	Exposures may occur with direct leakage from the reactor, product recovery, processing and packaging of dry powder, equipment cleaning, and maintenance.	Glovebox or other sealed enclosure with HEPA-filtered exhaust Appropriate equipment for monitoring toxic gas (e.g., CO)

Emergency Procedures

Because of the considerations described above, NIOSH recommends a specific spill kit for responding to nanomaterial spills. Cornell laboratories working with these materials should review the NIOSH spill management guidelines and develop specific procedures for managing these events. Contact Cornell EHS for assistance in developing these plans.

References

This information above is based on NIOSH Publication No. 2012-147: General Safe Practices for Working with Engineered Nanomaterials in Research Laboratories. However, best practices in this field are evolving rapidly and these other references should be reviewed to assure that the most current information is being used in managing the safety and health aspects of your work:

NIOSH Publications:

American Industrial Hygiene Association: