In a laboratory context, nanoparticles are engineered materials with a characteristic length of 1-100nm. Nanoparticles are commonly present in solution or suspension, or attached to a polymer. On occasion, they may also be handled as a dry powder. Nanoparticles exhibit very different properties from larger particles of the same composition.
The hazards associated with nanoparticles are not well characterized. Apart from a few species, the toxicity of nanoparticles are generally unknown. Until sufficient scientific evidence is present, all nanoparticles should be treated as hazardous to health and the environment. Reasonable measures should be taken to prevent human exposure and release to the environment.
- Some nanoparticles have shown greater toxicity than larger particles of the same composition (titanium dioxide, aluminum trioxide).
- Nanoparticles in insoluble form may be more toxic than soluble forms of the same material.
- Particles of this size range penetrate deeply into the lungs upon inhalation and cause adverse health effects.
- Dry powders can be highly reactive and pose a fire/explosion hazard.
The following precautions are recommended due to the largely unknown toxicity of nanoparticles.
- Whenever possible, work with nanoparticles in solution or attached to substrates.
- Work with nanoparticles in the form of a dry powder should be carried out in a fume hood, ducted BSC, or glove box. Recirculating hoods equipped with HEPA filtration (e.g., un-ducted BSC) may provide adequate ventilation, but ducted hoods are preferred.
- Reaction vessels or furnaces containing nanoparticles should not be vented into the building. A dedicated local exhaust is preferred.
- Dispose of nanoparticles and nanoparticle containing mixtures as a separate waste stream. Do not combine nanoparticles with other types of waste that do not contain nanoparticles. Fill out a Hazardous Waste Pick-Up Form for disposal of nanoparticle containing waste streams.
- Work areas where dry nanoparticles have been present should be wetted and wiped down with absorbent paper towels after each workday. Alternatively, disposable bench paper may be used.
- If a spill of dry nanoparticles occurs, do not sweep or brush the dry material. If the material cannot be wetted and collected, a HEPA filtered vacuum should be used and vented through a fume hood.
- Safety glasses and lab coats are required when working with nanoparticles.
- Double Nitrile gloves are recommended.
- If work with nanoparticles must occur outside of a fume hood, proper respiratory protection must be worn. Contact EHS for assistance.