Revised on
01/26/17 02:50pm
SafetyNet #
132

Nanotechnology: Guidelines for Safe Research Practices

Contact information

Introduction

This Safety Net provides environmental, health and safety information to researchers working with engineered nanoparticles, and should be incorporated as a standard operating procedure in each laboratory’s chemical hygiene plan.  Given the evolving knowledge base regarding health effects of nanoparticles, this fact sheet may be updated.  Always check with EH&S (530-752-1493) for the latest information.

Nanoparticles are materials that have at least one dimension between 1-100 nanometers. Particles in this size range have always been present in Earth’s air.  Nanoparticles may be naturally occurring (such as in volcanic ash), produced as unintentional byproducts (such as in auto emissions) or intentionally created or “engineered.”  These very small particles often have properties radically different from those of larger particles of the same composition, making them of interest to researchers and of potential benefit to society.  This Safety Net focuses on lab practices researchers should follow to protect themselves from the hazards of engineered nanoparticles.

Nanoparticles can be spheres, rods, tubes, and other geometric shapes or mixtures with various shapes.  Any nanoparticle hazards may depend on shape.  The small particles may be bound to surfaces or substrates, put into solution or suspension, attached to a polymer, or in a few cases handled as a dry powder.  Various nanoparticles can be created in the laboratory under experimental procedures, and some can be purchased from commercial vendors.  Often in research the amount of material used is small, generally less than a gram.

It is believed that some engineered nanoparticles may present health effects following exposure, based in part on air pollution studies that show smaller particles get deep into the lungs and can cause human illness.  However, laboratory research commonly involves handling nanoparticles in liquid solutions or other forms that do not become easily airborne, and even free formed nanoparticles tend to agglomerate to a larger size.  Materials that are comprised (in part) of nanoparticles may be sources of airborne nanoparticles, for example, as a result of abrasion or cutting of the materials.

When research involves work with engineered nanoparticles for which toxicity is not yet known completely, it is prudent to assume the nanoparticles may be toxic, and to handle the nanoparticles using the laboratory safety techniques outlined below.

Potential Routes of Occupational Exposure to Researchers

There are four possible routes of workplace exposure to nanoparticles:  inhalation, ingestion, skin absorption, and injection.

Skin absorption.  In some cases nanoparticles have been shown to migrate through skin and be circulated in the body.  If the particle is carcinogenic or allergenic, even tiny quantities may be biologically significant.  Skin contact can occur during the handling of liquid suspensions of nanoparticles or dry powders or as a result of tranpsort of the nanoparticles through air.  Skin absorption is much less likely when the nanoparticles are solid bound or matrixed.  Researchers should use double nitrile gloves to protect themselves from skin absorption and contamination, as well as protect their research materials from being contaminated.  Outer gloves should always be removed inside a fume hood or under the influence of a local exhaust ventilation system/device and placed into a sealed bag.  This procedure will help prevent the particles from becoming airborne in the laboratory.

Ingestion.  As with any material, ingestion can occur if good hygiene practices are not followed.  Once ingested, some types of nanoparticles might be absorbed and transported within the body by the circulatory system.  To prevent ingestion, eating, drinking and chewing of gum are not allowed in areas where hazardous materials are used or stored.  Also, spills of nanoparticles should be quickly and properly cleaned up, as detailed below.

Inhalation.  Respiratory absorption of airborne nanoparticles may occur through the mucosal lining of the trachea or bronchioles, or the alveolus of the lungs.  Because of their tiny size, certain nanoparticles appear to penetrate deep into the lungs and may translocate to other organs following pathways that are not significant when particles are larger.  Thus, whenever possible, nanoparticles are to be handled in a form that is not easily made airborne, such as in a solution, on a substrate, or inside an isolated environment.

Injection.  Exposure by accidental injection (skin puncture) is also a potential route of exposure, especially when a person is working with animals or needles.  To prevent this exposure, wear double nitrile gloves and a lab coat, and apply the standard practices for working with sharps.

Laboratory Safety Guidelines for Handling Engineered Nanoparticles

The current practices for working with engineered nanoparticles safely are essentially the same as one would use when working with any research chemical of unknown toxicity.

    The current practices for working with engineered nanoparticles safely are essentially the same as one would use when working with any research chemical of unknown toxicity.

    1. Use good general laboratory safety practices as stated in your chemical hygiene plan.  Wear double gloves (preferably nitrile gloves), safety glasses or goggles, and appropriate protective clothing.  Place Tacki-Mat (or similar sticky walk-off mat) at the exit to reduce the likelihood of spreading nanoparticles.

      2. All personnel participating in research involving nanoscale materials need to be briefed on the potential hazards of the research activity, as well as on proper techniques for handling nanoparticles.  The contents of this Fact Sheet can serve as a useful component of this training.  As with all safety training, written records need to be maintained to indicate who has been trained on this topic.

        3. Storage, consumption, and use of food, beverage, medicines, tobacco, chewing gum, and the application of cosmetics or handling of contact lenses are prohibited in areas where hazardous chemicals, including engineered nanoparticles, are used or stored.

          4. When purchasing commercially available nanoscale materials, be sure to obtain the Safety Data Sheet (SDS) and to review the information in the SDS with all persons who will be working with the material.  Note, however, that given the lack of complete knowledge of toxicity of nanoparticles, the information on an SDS may be more applicable to the properties of the bulk material.

            5. In some cases, the manufacture of nanomaterials involves the use of chemicals that are known to be hazardous or toxic.  Be sure to consider the hazards of the precursor materials when evaluating the process hazard or final product.  Users of any chemicals should make themselves familiar with the known chemical hazards by reading the SDS or other health hazard literature.

              6. To minimize airborne release of engineered nanoparticles to the environment, nanoparticles are to be handled in solutions, or attached to substrates so that dry material is not released.  When this is not possible, nanoscale materials should be handled with engineering controls such as a HEPA-filtered local capture hood or glove box.  If neither is available, work should be performed inside a laboratory fume hood.  HEPA-filtered local capture systems should be located as close to the possible source of nanoparticles as possible, and the installation must be properly engineered to maintain adequate ventilation capture.

                7. Use fume exhaust hoods to expel any nanoparticles from tube furnaces or chemical reaction vessels.  Do not exhaust aerosols containing engineered nanoparticles inside buildings.

                  8. If you must work outside of a ventilated area with nanomaterials that could become airborne, wear a respirator with NIOSH-approved filters that are rated as N-, R- or P-100 (HEPA).  EH&S will work with researchers to provide the most appropriate type of respirator.  Refer to the UC Davis Respiratory Protection Program for requirements.

                  9. Lab equipment and exhaust systems used with nanoscale materials should be wet wiped and HEPA vacuumed prior to repair, disposal, or reuse.  Construction/maintenance crews should contact EH&S for assistance.

                    10. Spills of engineered nanoparticles are to be cleaned up immediately.

                    1. Personnel should wear double nitrile gloves and either vacuum up the area with a HEPA-filtered vacuum or wet wipe the area with towels, or both.
                    2. For spills that might result in airborne nanoparticles, proper respiratory protection should be worn (see item 8 above).  For assistance with cleaning up any chemical spill contact EH&S.
                    3. Do not brush or sweep spilled/dried nanoparticles.
                    4. Place Tacki-Mat at the exit to reduce the likelihood of spreading nanoparticles.

                    11. Because many engineered nanoparticles are not visible to the naked eye, surface contamination may not be obvious.  Work surfaces should be wet-wiped regularly – daily wiping is recommended.  Alternatively, disposable bench paper can be used.

                    12. All waste engineered nanoparticles should be treated as chemical hazardous waste unless the waste determination shows it to be non-hazardous.  Dispose and transport waste nanoparticles in solution according to the hazardous waste procedures for the solvent.  Waste nanoparticles on a substrate or as a result of decomissioning equipment used with nanoparticles should also be treated as chemical hazardous waste.  Wipers, bench paper, gloves, and other lab debris contaminated with nanoparticles should be disposed as hazardous waste.  If you have questions on how to dispose a specific nanoparticle waste, call EH&S for more information.

                    For more information on Health and Safety of Nanotechnology visit the following web sites:

                      NIOSH (http://www.cdc.gov/niosh/topics/nanotech/)

                      National Nanotechnology Initiative (http://www.nano.gov/)

                      EPA (http://www3.epa.gov/)

                      Woodrow Wilson International Center for Scholars (http://nanotechproject.org/)

                      Rice University (http://cnst.rice.edu/)

                      This information was developed in consultation with the University of California Lab Safety Work Group, a subcommittee of the University of California Industrial Hygienists and Safety Steering Committee.  The author gratefully acknowledges the input of Dr. Gang-Yu Liu, Professor of Chemistry, Dr. Bruce Gates, Professor of Chemical Engineering, and Dr. Frank Yaghmaie, Director, Northern California Nanotechnology Center, UC Davis.