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Nanomaterials

Nanomaterials Safety Program

Nanomaterials are special because they have the potential to behave differently than the same material in the macro size range.  Therefore, what is known about the macro material’s toxicity profile and how it may cause adverse effects may not be applicable to the nanomaterial.  This is why traditional methods of assessment do not apply to nanomaterials.

This program will outline a risk based approach to controlling and reducing the risk of working with Nanomaterials at any University of Waterloo facility.

For the purpose of this program a nanomaterial will be defined as follows:

“a natural, incidental, or manufactured material containing particles, in an unbound state or as an aggregate or agglomerate where 50% or more in the number distribution are comprised of particles with one or more of its dimensions in the size range of 1 nm to 100 nm.”

Purpose:

The purpose of the University of Waterloo’s Nanosafety Program is to outline the responsibilities and processes required to minimize the risk of working with nanomaterials at the University of Waterloo.

Scope:

This program covers all work being conducted with nanomaterials.  This means any individual whether faculty, staff, contract worker, graduate student, co-operative student or volunteer must abide by the rules set forth in this document.

For anyone working with nanomaterials, this program guide will outline:

  • their roles and responsibilities
  • how to assess the risk of working with nanomaterials
  • how to respond to emergencies involving nanomaterials

Roles and Responsibilities

All individuals involved in the use, manipulation, handling, and research of nanomaterials have a role in maintaining a safe work and learning environment.  The University of Waterloo has outlined the responsibilities expected for each role below:

Principle Investigators:

The primary responsibility for the safety of workers, students, and the public lies with the Principal Investigator.  The principal investigator is considered a supervisor under the Occupational Health and Safety Act in Ontario.  In this role they must ensure the following duties are met:

  • Identify all hazards associated with use and manipulation of nanomaterials
  • Assess and control risks associated with the identified hazards
  • Communicate:
    • the hazards of working with and being exposed to nanomaterials and other laboratory substances required for the work being conducted. 
    • the control measures required to reduce the risk of working with these substances.
  • Ensure workers and students are made competent to perform the work they have been assigned through training and any other means that the PI or Safety Office feels is reasonable.
  • Develop written standard operating procedures (SOPs) to outline how all processes with nanomaterials will be performed and train all workers on the SOPs developed
  • Respond to worker reports of hazards in a timely manner with appropriate action
  • Meet all legislative requirements and university policies associated with work with nanomaterials
  • ​Investigate unintentional exposures and incidents involving nanomaterials

Researchers, Workers & Students:

Researches, workers, and students are expected to:

  • Report any hazards to their direct supervisor
  • Follow all procedures as written or required for the work they are performing
  • Follow all legislative requirements as deemed necessary for them to complete their work
  • Attend any training sessions deemed necessary by the University of Waterloo or their supervisor
  • Wear and use any personal protective equipment as required

The Safety Office:

The safety office’s main function is to support researchers, staff, employees, and students in assessing and controlling the risks they are exposed to.  For nanomaterials in particular this means:

  • Providing a guidance manual (this document) on assessing and controlling the health risks of working with nanomaterials
  • Providing consulting services in the assessment and control of health risks
  • Providing exposure assessments

Risk Assessment

Many of the health risks associated with nanomaterial use are unknown.  For this reason, the University of Waterloo requires that a risk assessment is conducted PRIOR to the use of nanomaterials.  This also includes processes that cause the generation of nanomaterials. 

A risk assessment involves examination of the potential harm a material may cause based upon two factors:

  1. Its properties; and,
  2. How it is used. 

At the University of Waterloo, we have adapted the Control Banding Nanotool (CB Nanotool) developed by the Lawrence Livermore National Laboratory located in Livermore California.

This tool will guide the user through a series of questions to ascertain the risk level work with a particular material may pose.  This risk is quantified into 1 of 4 categories called risk levels.  Risk Level 1 represents the scenario posing minimal risk, whereas risk level 3 represents scenarios posing the greatest risk.  Risk Level 4 is specifically designated for operations that are not stationary operations and cannot be controlled through the use of typical engineering controls.  Examples include cleaning spills or performing maintenance on gloveboxes, fumehoods, biological safety cabinets or other devices contaminated by nanomaterials.

The tool calculates risk by considering two categories of information supplied by the researcher:

  • the hazard potential of the material based upon its physical and chemical properties
  • the exposure potential of an individual based upon how the material is being used

The risk assessment is currently in the form of an excel spreadsheet.  To access it, please open the following link: UW Nanomaterials Risk Assessment Form.  Print out the assessment when you are done.  This will be the document you can use to illustrate that you have performed a risk assessment on the materials you are working with. 

When doing the risk assessment, you will note that you can select “unknown” for the physical properties of the material.  Keep in mind that selecting “unknown” may elevate the risk of the material.  To ensure that the controls required are not overprotective, the Safety Office advises that you contact the supplier to find out as much hazardous information as possible.  The more you know, the more accurate the assessment will be.  The less you know the more protective the result will be.  Also keep in mind that any information you enter in the risk assessment spreadsheet should be referenced or sourced.

As a guideline, the Safety Office recommends you request the following information from your supplier before conducting the risk assessment:

  • MSDS for the nanomaterial (many times suppliers will just supply MSDS’s for the parent material)
  • Transmission electron microscope scan (to determine agglomeration characteristics)
  • Particle shape
  • Hazardous information with respect to:
    • carcinogenicity, reproductive toxicity, mutagenicity,
    • hepatotoxicity (affects liver), nephrotoxicity (affects kidneys), neurotoxicity (affects nerves, 
    • mutagenicity; and,
    • the material’s potential to impair lung function or cause harm to skin

Controls

A completed risk assessment will outline the type of control required for each activity being performed.  A more detailed description of each Risk Level and the required control for each is presented below.

Assigning Risk

The risk assessment form assigns risk levels using the matrix illustrated in Figure 1 below.

This table provide a visual image of how "severity" and "exposure" combine meaninfully into a risk level.

Figure 1: Risk Level Assignment.

Risk Level 1 (RL1):

Materials that fall into this category are of low toxicity with physical properties that limit the substance’s ability to become airborne.  In many cases, these materials are bound in a liquid or solid matrix and are handled in a way that will limit exposure.

As both toxicity and exposure characteristics are low, working with this material in a standard fume hood or on a bench top will be acceptable. 

Risk Level 2 (RL2):

Risk level 2 nanomaterials encompass the largest group of materials.  These materials can have a range of toxicity and physical characteristics.

The control recommended by the Safety Office constitutes a powder handling enclosure.  This can take the form of a Level 1 or 2 Biosafety Cabinet or something else of comparable design.  The minimum criteria are:

  • Enclosure with frontal opening panel
  • HEPA filter exhaust
  • Must exhaust to outside if being used with a chemical that poses a secondary hazard like a flammable or toxic solvent.
This image depicts class 1 and 2 type biosafety cabinets.

Figure 2: Examples of a Class 1 Biosafety Cabinet and Class 2 B2 Biosafety Cabinets.  Images in this figure are curtsey of NuAire Inc. http://www.nuaire.com/products/biological-safety-cabinets.html

Important requirements for use with toxic and/or flammable compounds:

  1. The BSC must be hard ducted to an external exhaust system
  2. If a Class II BSC is being used, only Class II B2 can be used, as this is the only B2 style cabinet that does not recirculate lab air.
  3. Construction material of cabinet must suit the materials being used in the cabinet.  For example, some plastics may not be compatible with some solvents.

Risk Level 3 (RL3):

Risk level 3 nanomaterials are those that will pose a significant risk to an individual.  These materials are almost always in a powder form, and tend to be highly or extremely toxic.  To minimize risk, these materials should always be handled in a glove box.  We recommend that the glovebox possess the following minimum attributes:

  • HEPA filter on outlet
  • Antechamber to allow for a secondary protection when moving product into and out of the glovebox.
  • Made of a material composition that is compatible to the materials being used in the glovebox (namely solvents)
  • Must exhaust to outside if being used with a chemical that poses a secondary hazard like a flammable or toxic solvent.

Illustration of a glovebox.

Figure 3: Illustration of a HEPA filtered glove box.  Image curtesy of Cleatech, Cleanroom and Laboratory Solutions.

*Note, that in most cases, solvents are not compatible with the blowers for the system.  Furthermore, if a solvent is required, the glovebox will need to be vented to the exterior of the building or the building ventilation system.

If you perform the risk assessment, and are unclear about the result, please contact the Safety Office for a review.  However, please keep in mind that in order for an accurate review of your material to occur we will ask for the following information:

  • MSDS for the nanomaterial and potentially the parent material
  • MSDS for any other compound required for the work being conducted
  • A TEM or SEM scan in which agglomeration can be examined
  • A summary of the experimental process that includes how the material is handled from the purchase of the material to its ultimate disposal (cradle to grave).

Emergency Procedures

Spills of nanomaterials pose the greatest risk to individuals

Risk level 2 and 3 (inside containment)

  1. Use personal protective equipment appropriate for risk level.
  2. Notify occupants of laboratory.
  3. Use absorbent material with an appropriate solvent to wet wipes the areas or HEPA filtered vacuum.
  4. Place all cleaning materials, disposable PPE and waste in plastic bag.
  5. Seal and wipe exterior.
  6. Place bag in secondary bag.
  7. Seal secondary bag and wipe exterior.
  8. Label nanomaterial waste with description for disposal (i.e. Nanomaterial contains nano-silver material).

Spills procedures risk level 2 and 3 (outside containment)

  1. Evacuate occupants of laboratory, close laboratory door and secure area.
  2. Contact UWaterloo Police at ext. 22222.
  3. Provide the following information:
  4. Location of spill
    1. Material
    2. Quantity
    3. Assessment of risk
  5. Remain with UWaterloo Police until spill team arrives.