Precautionary Measures for Experimental Work Involving Engineered Nanoparticles at HKUST
January 2009 (Revised)
Health, Safety and Environment Office
Hong Kong University of Science and Technology
“Engineered nanoparticles” is defined as nanomaterials existing in a particle form, with a diameter less than 100nm, and are intentionally produced for specific purposes. This is to differentiate from natural particles such as atmospheric aerosols, and incidental man-made particles such as diesel exhaust, that are of the same size range.
It is well known that when materials are reduced to nanosize, there are novel physicochemical properties not found in the original materials. In general, both chemical and biological activities of nanoparticles are increased, compared with the parent materials. Because of these new and mostly not well characterized properties, and their potential adverse health and environmental effects as demonstrated in preliminary studies, it is prudent to adopt the following precautionary measures in experiments involving engineered nanoparticles:
Risk Assessment
- Treat as hazardous. Engineered nanoparticles are to be treated as hazardous, regardless of the physicochemical properties of the parent materials.
- Treat as new chemical. Engineered nanoparticles are to be treated as “new” chemicals. The material and safety information (i.e. SDS) of the parent materials can only be considered as a “starting point” at best, for assessing risk of the derived nanoparticles.
- Assess impact throughout lifecycle. Assess potential impact throughout the lifecycle of engineered nanoparticles. Seek to destroy the nanoparticles or at least the “nano-features” of the materials after they serve their experimental purposes.
Handling Nanoparticles
- Avoid aerosolization. Conduct processes that may aerosolize nanoparticles inside a properly functioning fumehood, preferably equipped with a HEPA filter to prevent releasing nanoparticles to the environment. A biological safety cabinet (which has a built-in HEPA filter) may be considered if the process does not involve volatile chemicals.
- Respiratory protection. A properly fitted N-95 or equivalent particulate respirator should be worn by workers handling dry nanoparticles, especially for processes that cannot be contained in a fumehood. If the potential of aerosolization is high, a full-face elastomeric respirator with HEPA filter cartridges, or a half-face respirator coupled with a pair of safety goggles should be used.
- Avoid skin contact. Although not much information is available on penetration of nanoparticles through glove materials, at least a pair of general purpose chemical-resistent gloves (e.g. nitrile) should be worn when handling engineered nanoparticles.
Releasing Nanoparticles into the Environment
- Risk-benefit analysis. Do not release engineered nanoparticles into the environment for experimental purposes unless the benefits clearly outweigh the risks.
Disposal of Waste Containing Nanoparticles
- Treat as chemical waste. Do not allow nanoparticles to enter regular trash or sewer. Find a suitable chemical waste stream for disposal.
- Seek to remove from waste stream. Consider ways to either remove the nanoparticles from wastes, or to destroy the “nano-features” of the materials, e.g. dissolving nanoparticles in suitable solutions, before disposal.
Responding to Nanoparticle Spills
- Treat as a hazardous material spill
- Evacuate area, allow 20 minutes for nanoparticles to settle.
- Put on HEPA respirator, gloves and coverall
- Remove spilled dry nanomaterials by HEPA vaccum cleaner
- Use normal sorbent materials for spilled liquid containing nanomaterials
- Contact HSEO for major spill or assistance
Referenences:
Please contact Dr Samuel Yu of HSEO at Ext 6547 or samyu@ust.hk if you have any questions or comments.