Guidelines for Safe Use of Nanomaterials

PURPOSE: These guidelines establish safe work procedures for personnel working with nanomaterials.

SCOPE:  These guidelines cover all of the Missouri University of Science and Technology campus.

APPLICABILITY:  These guidelines cover all users of nanomaterials and other personnel present in the lab while they are being used, facilities workers, and first-responders to incidents involving nanomaterial releases.

INTRODUCTION to Nanomaterials: The International Organization for Standardization (ISO) has developed nomenclature and terminology for nanomaterials. According to ISO 27687:2008, a nano-object is a material with one, two, or three external dimensions in the size range from approximately 1-100 nanometers (nm).

Sub-categories of a nano-object are:

• Nanoplate: a nano-object with one external dimension at the nanoscale (i.e. 1-100nm)
• Nanofiber: a nano-object with two external dimensions at the nanoscale, with a nanotube defined as a hollow nanofiber and a nanorod as a solid nanofiber
• Nanoparticle: a nano-object with all three external dimensions at the nanoscale

PROCEDURE:

I.  Working safely with Nanomaterials

At this time there are no published regulations for safe work practices with nanomaterials. However, the National Institute for Occupational Safety and Health (NIOSH) recommends that worker exposure be kept below 1 µg/m³ 8-hour time-weighted average during a 40 hour work week. Manmade nanoparticles may pose risk to human health due to their composition, size and ability to cross cell membranes. Engineered nanomaterials may exhibit higher toxicity due to their size compared to larger particles of similar composition. Current information about risk associated with nanomaterials exposure is limited. Safe work practices are generally based on understanding the hazards of the materials at a larger scale and may not be fully accurate for the same material in the nano-size. Until more definitive information becomes available these guidelines, based off of NIOSH Current Intelligence Bulletin 65 – Occupational Exposure to Carbon Nanotubes and Nanofibers, will be established and followed as precautionary work practices. Risk assessments and control strategies for nanomaterial research will be based on the most current toxicological data, exposure assessments, and exposure control information and these guidelines will be updated as needed.

II. Engineering Controls

To prevent adverse health effects from exposure to nanomaterials, steps to eliminate exposure and minimize risks early in the design or re-design of manufacturing and down-stream user processes must be taken. The best way to do this is through engineering controls. For personal and environmental protection all manipulations with nanomaterials must be performed in either a chemical fume hood (annually tested by Environmental Health and Safety; contact ext. 4305 if your hood needs testing) or a local exhaust ventilation system with a High Efficiency Particulate Air (HEPA) filter.

III. Work Practices

To help minimize exposure to nanomaterials the following good work practices must be followed in addition to general laboratory practices:

• Nanomaterial selection
  • When possible nanomaterials should be handled in solutions or attached to substrates to minimize airborne release
  • Use safety data sheets (SDSs) when using unfamiliar nanomaterials. Please note that many safety data sheets are not based on the nano-size scale but rather the bulk material and may contain information not fully accurate or relevant.
• Safety Equipment
  • Know the location and proper use of safety showers, eye wash stations, fire extinguishers, and fire alarms.
• Hygiene
  • Storage or consumption of food or drink in areas where nanomaterial are handled and/or stored is prohibited.
  • Hand washing is required before and after working with nanomaterials, when removing personal protective equipment (PPE), and before leaving the lab area.
  • Lab coats can become contaminated with nanomaterials and should not be worn outside the lab.
• Storage and labeling
  • Store all nanomaterials in a well-sealed container
  • Label all containers with the identity of the contents and be sure to include the word “nano”
  • Include hazard warnings and concentration on label
  • When transporting nanomaterials use a double containment system
• Cleaning
  • Clean all lab work areas with a HEPA filtered vacuum cleaner or use a wet wipe method

IV. Personal Protective Equipment

There are no regulations or guidelines for the selection of protective clothing or other apparel against exposure to nanomaterials. Some nanoparticles have shown the ability to penetrate the skin and possibly enter the bloodstream. If the particles are suspended in a liquid, penetration of the liquid can be enhanced if the glove is permeable to the liquid. Outer clothing should consist of at least a lab coat, gloves, and safety goggles while working with nanoparticles. Clothing requirements can be upgraded to higher levels of protection as circumstances require. If worker exposure to nanomaterials remains a concern after all feasible engineering controls are instituted, respiratory protection may be deemed necessary.  If respiratory protection is deemed necessary by EH&S or respirators will be used voluntarily, all parts of Missouri S&T’s Respiratory Protection Program must be followed.

V. Spill Management

Cleanup of spills will comply with current practices and modified with information about the reactive characteristics of the particles being used. Cleaning should always be done in a manner that will minimize the creation of aerosols. Clean up should be done using a wet wipe method for smaller spills. For large spills collection of material with a HEPA filtered vacuum followed by wet wiping may be needed. DRY SWEEPING IS PROHIBITED.

VI. INFORMATION AND TRAINING

• The Principle Investigator shall train employees who handle nanomaterials on the hazards of nanomaterials and what to do in the event of an exposure or a spill or other emergency.
• The SDS together with these guidelines shall be used to train employees on the hazards of nanomaterials. Note: Information contained in the SDS may not be fully accurate and/or may be more relevant to the properties of the bulk material rather than the nano-size particles.

VII. RESPONSIBILITIES

Principle Investigatory (PI):

• Must ensure personnel are trained in the safe use of nanomaterials and these guidelines.

Environmental Health & Safety (EHS):

• Provide annual velometer test of fume hood.  Tag hoods that have deficient air flow and notify Facilities on these hoods and any others that need repair.
• Follow up on exposure or spill incidents.
• Review and update these guidelines, as necessary.

 Sources:

www.cdc.gov/niosh/docs/2013-145/pdfs/2013-145.pdf

www.cmu.edu/ehs/fact-sheets/nanoparticle-safety.pdf

www.ehs.psu.edu/occhealth/nanomaterials.cfm

www.stanford.edu/dept/EHS/prod/researchlab/IH/nano/lab_safety_guidelines.html

(Missouri S&T’s Environmental Health & Safety Office, June 2013)