Nanotechnology SafetyPrecautionary Measures for Employers and Workers Handling Engineered Nanomaterials
Overview: Given the limited amount of information about the health risks, it is prudent to take measures to minimize worker exposures.
- For most processes and job tasks, the control of airborne exposure to nanoaerosols can be accomplished using a wide variety of engineering control techniques similar to those used in reducing exposure to general aerosols.
- The implementation of a risk management program in workplaces where exposure to nanomaterials exists can help to minimize the potential for exposure to nanoaerosols. Elements of such a program should include:
- evaluating the hazard posed by the nanomaterial based on available physical and chemical property data and toxicology or health effects data.
- assessing potential worker exposure to determine the degree of risk.
- the education and training of workers in the proper handling of nanomaterials (e.g., good work practices).
- the establishment of criteria and procedures for installing and evaluating engineering controls (e.g., exhaust, ventilation) at locations where exposure to nanoparticles might occur.
- the development of procedures for determining the need and selection of personal protective equipment (e.g., clothing, gloves, respirators).
- the systematic evaluation of exposures to ensure that control measures are working properly and that workers are being provided the appropriate personal protective equipment.
- Engineering control techniques such as source enclosure (i.e., isolating the generation source from the worker) and local exhaust ventilation systems should be effective for capturing airborne nanoparticles. Current knowledge indicates that a well-designed exhaust system with a high-efficiency particulate air (HEPA) filter should effectively remove nanoparticles.
- The use of good work practices can help to minimize worker exposures to nanomaterials. Examples of good practices include; cleaning of work areas using HEPA vacuum pickup and wet wiping methods, preventing the consumption of food or beverages in workplaces where nanomaterials are handled, and providing hand-washing facilities and facilities for showering and changing clothes.
- No guidelines are currently available on the selection of clothing or other apparel (e.g. gloves) for the prevention of dermal exposure to nanoaerosols. However, some clothing standards incorporate testing with nanoscale particles and therefore provide some indication of the effectiveness of protective clothing with regard to nanoparticles.
- Respirators may be necessary when engineering and administrative controls do not adequately prevent exposures. Currently, there are no specific exposure limits for airborne exposures to engineered nanoparticles although occupational exposure limits exist for larger particles of similar chemical composition. The decision to use respiratory protection should be based on professional judgment that takes into account toxicity information, exposure measurement data, and the frequency and likelihood of the worker’s exposure. Preliminary evidence shows that for respirator filtration media there is no deviation from the classical single-fiber theory for particulates as small as 2.5 nm in diameter. While this evidence needs confirmation, it is likely that NIOSH certified respirators will be useful for protecting workers from nanoparticle inhalation when properly selected and fit tested as part of a complete respiratory protection program.