Nanotechnology Safety Resources

ACS Guidelines for Safe Handling of Nanomaterials in the Laboratory

The foundation of safe handling of engineered nanomaterials rests on the principles of good laboratory practices.⁸ The following key considerations are adapted from guidelines provided by Dr. Peter Lichty (Lawrence Berkeley National Laboratory) and comments received from members of the ACS safety community. They follow laboratory safety’s organizing principle of RAMP: Recognize hazards, Assess risk, Minimize risk and Prepare for emergencies.

Recognize Hazards and Assess Risks:

• Be sure to consider the hazards of precursor materials in evaluating process hazards such as acidity, basicity, oxidizing or reducing strength, and flammability. Perform thorough hazard assessment and risk assessment for the nanomaterial syntheses (Figure 1).

• Consideration should also be given to the high reactivity of some ultrafine powdery materials, which poses potential fire and explosion hazards.

• Evaluate nanomaterial transfer methods, temperature controls and other process controls.

Minimize Risks

Selection of Nanomaterials, and Substitution

• Whenever possible, substitute dry nanomaterials with those in solution or bound to substrates.

Engineering Controls

• Given the differing synthetic methods and experimental goals, aerosol emissions controls should be carefully designed for the process, tested, and properly operated to be effective; see the National Institute for Occupational Safety and Health (NIOSH) Protecting Workers During the Handling of Nanomaterials. Controls should meet the respiratory protection standards in the Occupational Safety and Health Administration (OSHA) Personal Protective Equipment, Standard 1910.134 29 CFR 1910.134, if respiratory protection is used.

• NIOSH guidance notes that engineering control systems, such as adequate ventilation or scrubbing of contaminants, are the preferred control methods for reducing potential exposures. A primary engineering control used in the nanotechnology industry during the handling, weighing, mixing, or sonication of engineered nanomaterials is a ventilated enclosure. NIOSH recommends the use of local exhaust ventilation (e.g., laboratory chemical fume hoods; Figure 2). Exhaust air should be passed through a high-efficiency particulate air (HEPA) filter and, when feasible, released outside the facility. If the exhaust air is recirculated, then steps should be taken to ensure that recirculated air does not contain the nanoparticles (see NIOSH’s General Safe Practices for Working with Engineered Nanomaterials in Research Laboratories). Other engineering controls for safe handling include nanomaterial handling enclosures (glove boxes or isolators; Figure 3) and biological safety cabinets. Additional details are available in NIOSH’s Controlling Health Hazards When Working with Nanomaterials: Questions to Ask Before You Start.

• Laboratory equipment and exhaust systems should also be evaluated for any nanomaterial contamination before removal, remodeling, or repair.

• Equipment that was previously used to manufacture or handle nanoparticles should also be evaluated for any nanomaterial contamination before disposal or reuse.

Administrative Controls

• Administrative controls, such as appropriate signs and labels, access control, and a chemical hygiene plan including standard operating procedures (SOPs) and hazard assessment, are important aspects of good laboratory practices and are part of a hierarchy of controls supporting the implementation of feasible and effective control solutions.

• Housekeeping is an important aspect to prevent any exposures to nanomaterials. The work area and equipment should be cleaned regularly to avoid any exposure. Immediately clean spills involving nanomaterials according to written protocols or SOPs and using proper personal protective equipment. Typical methods for cleaning spills can be used for cleaning surfaces contaminated with dry powder nanomaterials. Never use flammable solvents for cleaning nanomaterials with flammable or pyrophoric properties. Clean dry nanomaterials with damp cloths, or by wetting the powder before wiping. Avoid using compressed air or other high-energy techniques, such as brushing or shaking, to remove nanomaterials from clothing.

• Test vacuum cleaners used to clean up nanoparticles; use HEPA-filtered units. Personal protective equipment should be used during spill cleanups and equipment maintenance.

• Dispose of and transport waste nanoparticles according to hazardous chemical waste guidelines, such as EPA’s Managing Laboratory Hazardous Waste guidance document.

Personal Protective Equipment

•  Use good general laboratory safety practices as found in your organization’s chemical hygiene plan. Wear personal protective equipment (nitrile or chemical-resistant gloves, lab coats, safety glasses, face shields, and closed-toed shoes) as needed. Avoid skin contact with nanoparticles or nanoparticle-containing solutions by using appropriate personal protective equipment. The NIOSH Personal Protective Technology Program has the most up-to-date information on appropriate personal protective technologies for workforce safety. See also NIOSH’s General Safe Practices for Working with Engineered Nanomaterials in Research Laboratories.

• Respirators should be used only when engineering control systems are not feasible or where engineering controls alone may not be considered adequate to completely prevent exposure (see NIOSH’s General Safe Practices for Working with Engineered Nanomaterials in Research Laboratories). If it is necessary to handle nanoparticle powders outside of a HEPA-filtered powered-exhaust laminar flow hood, wear appropriate respiratory protection. The appropriate respirator should be selected on the basis of professional consultation, should meet NIOSH certification requirements, and should follow OSHA standards on respiratory protective equipment (Personal Protective Equipment, Standard 1910.134).

Training and Education

• Students and researchers should be provided with safety training and education to understand the nature of possible workplace exposures, health risks, routes of exposure, and instructions for reporting health symptoms, including proper use of engineering controls and maintenance of control. See below for training resources as well as NIOSH’s Protecting Workers During Nanomaterial Reactor Operations.

Preparing for Emergencies

Preparedness and response for nanomateral emergencies should follow the laboratory’s overall emergency planning. Start by reviewing the response to fires, spills and releases, and consider what additional steps might be appropriate based on this guidance. In particular, significant exposures or symptoms of a possible exposure should be reviewed by a medical professional, preferably an occupational health specialist.