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45.7 Work Process S. Specific Controls and Procedures — Engineered Nanomaterials
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ES&H Manual Chapter 45_45.7 Work Process S. Specific Controls and Procedures — Engineered Nanomaterials

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Chapter 45
CHEMICAL HYGIENE AND SAFETY PLAN

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Work Process S. Specific Controls and Procedures — Engineered Nanomaterials

  1. General Information
  1. Engineered nanomaterials (ENMs), also known as engineered nanoparticles, are defined as:
  1. Materials having structures with at least one dimension between 1 and 100 nanometers (nm)
  2. Intentionally created, as opposed to those that are naturally or incidentally formed
  1. ENMs do not include:
  1.  Larger materials that may have nanoscale features, for example etched silicon wafers
  2. Biomolecules (proteins, nucleic acids, and carbohydrates)
  3. Materials with occupational exposure limits (OELs) that address nanosize particles for that substance
  1. Unbound engineered nanoscale particles (UNPs) are defined as nanoscale particles that are not contained within a matrix under normal temperature and pressure conditions that would reasonably be expected to prevent the particles from being separately mobile and a potential source of exposure.
  1.  An engineered primary nanoscale particle dispersed and fixed within a polymer matrix, incapable as a practical matter of becoming airborne, would be “bound,” while such a particle loosely attached to a surface (e.g., nanowire forest grown on wafer) or suspended in liquid (e.g., nanoparticles in colloidal suspension) or a dry powder would be “unbound.”
  1.  A UNP worker is a worker who:
  1. Has the potential for inhalation of or dermal exposure to UNPs
  2. Routinely spends time in an area in which engineered UNPs have the potential to become dispersed in the air or on surfaces or
  3. Works on equipment that might contain or bear UNPs and that could release UNPs during servicing or maintenance
  1. Exposures to ENMs may occur through inhalation, dermal contact, or ingestion of UNPs. Because of their tiny size, UNPs can penetrate deep into the lungs and may translocate to other organs following pathways not demonstrated in studies with larger particles.
  2. In general, laboratory personnel should treat all new compounds, including ENMs of unknown toxicity, as though they could be acutely toxic in the short run and chronically toxic over time. ENMs whose hazards have been studied should be managed in a manner consistent with the observed risks.
  3.  Work involving these materials shall be added to a Work Planning and Control Activity. Consult the Work Planning and Control program (EH&S Manual Chapter 6).
  1. Training and Information
  1. Employees who either handle or who may be exposed to the hazards of ENMs must complete Chemical Hygiene and Safety Training (EHS 348) and Safe Handling of Engineered Nanoscale Particulate Matter (EHS 344).
  2. Activity leads are responsible for on-the-job training specific to hazards and controls of these materials for their work activities.  Information on hazards and minimum PPE requirements must be available to workers accessing work areas where these hazards are present such as through the entrance placard and co-located hazards in WPC activities.  EHS Health and Safety Representatives are available to provide assistance.
  1. Engineering Controls
  1. Conduct work that could generate UNPs in glove boxes, glove bags, laboratory fume hoods, or other negative-pressure or isolation enclosures. If a process (or subset of a process) cannot be enclosed, use other engineered systems to control fugitive emissions of UNPs or hazardous precursors that might be released. For example, use a local exhaust system such as an extractor arm.
  2. With regard to gloves worn in glove boxes: Consider using an inner pair of different-color gloves to detect small tears in glove-box gloves and/or wearing an outer pair of gloves to prevent degradation of glove-box gloves. Refer to Work Process I, Personal Protective Equipment, for selecting chemically resistant gloves.
  3. Avoid exhausting effluent air reasonably suspected to contain UNPs whose hazards are not well understood. Whenever practical, filter it or otherwise clean (scrub) it before release. High Efficiency Particulate Arresting (HEPA) filtration appears to effectively remove UNPs from air.
  4. Do not use horizontal laminar-flow hoods (“clean benches”) that direct a flow of air into the laboratory to control exposure to UNPs.
  5. Consider exhausting Type II biological safety cabinets, in which free UNPs are handled, directly to the exterior (hard-ducted) or through a thimble connection over the cabinet’s exhaust.
  6. Evaluate laboratory equipment and exhaust systems for contamination before removing, remodeling, or repairing them.
  1. Housekeeping
  1.  In so far as practicable, maintain all working surfaces (e.g., benches, glassware, apparatus, exhaust hoods, support equipment) free of UNP contamination. Some UNPs fluoresce under ultraviolet light, which can be useful in locating areas of contamination.
  2. Clean up dry UNPs using:
  1. A dedicated HEPA vacuum-tested and certified by EHS
  2. Wet wiping
  3. Other methods that do not involve dry sweeping or the use of compressed air
  1. Dispose of used cleaning materials and wastes as hazardous waste (see below).
  1. Chemical Inventory
  1. Enter all containers of commercially obtained ENMs into the Chemical Management System (CMS). The CMS has a checkbox for ENMs to allow easier identification of storage and use locations. Ensure this is checked when entering the material into the inventory.
  1.  Marking, Labeling, and Signage
  1. Post signs indicating hazards, minimum PPE requirements, and administrative control requirements at entry points into areas where ENMs are handled. Work Process AA, Posting Area Entrances, has specific posting requirements and instructions.
  2. Consult Work Process Y, Container Labeling, for labeling requirements for primary and secondary containers. Label containers to plainly indicate that the contents are in engineered nanoparticulate form, e.g., “nanoscale zinc oxide particles” or other identifier, rather than just “zinc oxide.”
  3. There may be practical limitations to carrying out these labeling requirements to small containers such as sample vials and tubes. Alternatives such as numbering or coding are permissible provided that the material’s identity and hazards are readily accessible (e.g., by means of a lab notebook, a spreadsheet, or some other equivalent means).
  4. When UNPs are being moved outside the work area, also include label text that indicates that the particulates may be unusually reactive and are potentially more toxic, quantitatively and qualitatively, than normal-scale forms of the same material.
  1. Storage
  1. Consult Work Process K, Chemical Storage, for hazardous-materials storage requirements, recommendations, and information on chemical incompatibility. Additional requirements are provided below.
  2.  Follow the storage guidelines in Work Process N, Specific Controls and Procedures — Flammables and Combustibles if the material is either flammable or combustible.
  1.  Personal Protective Equipment
  1. Skin and eye contact must be prevented. Wear PPE appropriate to the hazard, as identified through the WPC Activity. Obtain a hazard assessment from an EHS Health and Safety Representative to determine the selection and use of PPE. PPE required for a wet-chemistry laboratory, which is often appropriate for handling ENMs, includes:
  1. Laboratory coats
  2. Eye protection, e.g., safety glasses with side shields, face shields, chemical splash goggle, or other safety eyewear appropriate to the type and level of hazard. NOTE: Face shields or safety glasses alone do not provide sufficient protection against unbound, dry materials that could become airborne.
  3. Closed-toe shoes made of a low-permeability material
  4. Protective gloves
  1. Store gloves in a clean area outside of fume hoods and away from equipment that could potentially contaminate them.
  2. Wear polymer (e.g., nitrile rubber) gloves when handling ENMs and particulates in liquids. Choose gloves only after considering the resistance of the glove to the chemical attack both by the ENM and, if suspended or dissolved in liquid, the liquid. Consult the glove selection guides in Work Process I, Personal Protective Equipment. Disposable gloves may be appropriate.
  3. Change gloves often to minimize potential exposure hazards. Alternatively, double-glove.
  4. For glove-box gloves: Consider using an inner pair of different-color gloves to detect small tears in glove-box gloves and/or wearing an outer pair of gloves to prevent degradation of glove-box gloves.
  5. Wash hands and forearms after wearing gloves.
  1. Keep potentially contaminated clothing and PPE in the laboratory or change-out area to prevent ENMs from being transported into common areas. Use disposable lab coats if feasible, and discard of them as hazardous waste (see below) when they become unusable. If cloth lab coats are used, do not send them to a laundry unless the laundry (such as the Berkeley Lab contract lab coat provider) has specifically agreed to handle ENM-contaminated clothing.
  1. Engineered Nanomaterial-Bearing Waste Streams
  1. Consider any material that has come into contact with UNPs (and that has not been decontaminated) as belonging to an ENM-bearing waste stream. This includes gloves, other PPE, wipes, blotters, and other disposable laboratory materials used during research activities.
  2. Do not put material from ENM-bearing waste streams into the regular trash or down the drain.
  3. Collect ENM-bearing waste in an appropriate sealing container such as a plastic bag. Until the container is sealed, keep it in the laboratory hood. The container must remain sealed unless adding waste to it. It should be managed as hazardous waste, including completing the Hazardous Waste label when accumulation begins, and placing it in an identified SAA. The identity of the waste must be given on the label. For example, “Wipes contaminated with trace levels of carbon nanotubes” provides an appropriate level of description. In addition to the applicable hazards on the label, add "NANO" or "<100 nm" to the "Other" hazardous properties section. When the bag is full, close it, take it out of the hood, and place it into a second plastic bag or other sealing container in an SAA.
  4. Characterize and manage ENM-bearing waste streams per the requirements of the Waste Management program (EH&S Manual Chapter 20). Be sure to consider the properties of all components, for example, solvents in which the ENMs may be dissolved or suspended.
  1.   Emergency Procedures and Spills
  1. Refer to Work Process V, Emergency Procedures and Equipment, for Berkeley Lab policy and response procedures for chemical spills. Spills containing ENMs are generally handled in a manner similar to spills of other potentially hazardous materials, with the following additional requirements:
  1. Clean the spilled material using wet-wiping methods. Characterize, collect, and dispose of spill cleanup materials as ENM-bearing waste.
  2. Only HEPA vacuums that have been tested and certified by EHS may be used to vacuum nanomaterials. Do not dry-sweep or use compressed air.
  3. Consider using a walk-off mat such as a clean-room mat or “sticky mat” at access/egress points to reduce the likelihood of spreading nanoparticles. These are available through McMaster-Carr via the Laboratory’s Procurement & Property Web site.

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