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Nanomaterial Safety

Nanomaterial Safety. Created By: Dean Marinchek Supervised By: Dr. Larry Miller. Nanotechnology. Nanotechnology is the engineering and manipulation of materials at the molecular level The dimension of nanomaterials are between 1 and 100 nanometers 1nm is 1 billionth of a meter

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Nanomaterial Safety

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  1. Nanomaterial Safety Created By: Dean Marinchek Supervised By: Dr. Larry Miller

  2. Nanotechnology • Nanotechnology is the engineering and manipulation of materials at the molecular level • The dimension of nanomaterials are between 1 and 100 nanometers • 1nm is 1 billionth of a meter • A human hair is 50,000 nanometers in diameter

  3. Nanotechnology Particles created at the nanoscale have different chemical and physical properties than larger particles of the same material

  4. Carbon Nanotubes • Carbon Nanotubes (CNTs) in particular have unique electrical, mechanical, and thermal properties with a large potential in electronics, aerospace, and many other industries. • CNTs exist in two forms, single-wall (SWCNTs) and multi-wall (MWCNTs)

  5. Potential Health Hazards • Due to the relatively new nature of nanotechnology, research is still being conducted on the health hazards • Two facts must be known to determine if workers are at risk • The type and concentration of nanoparticles in the workplace • The specific properties of the nanoparticles that could potentially affect the body

  6. Potential Health Hazards • Workplace tasks that increase the risk of exposure • Handling powders of nanomaterials • Maintenance on equipment and processes used to produce or fabricate nanomaterials and the cleaning-up of spills and waste material containing nanomaterials • Cleaning of dust collection systems used to capture nanoparticles • Machining, sanding, drilling, grinding, cutting, or other mechanical disruptions of materials containing nanoparticles

  7. Research on Health Risks • In lab animals, some nanoparticles reach blood, brain, and other organs when inhaled • This causes adverse effects such as inflammation and fibrosis in the lungs and other organs • Recent studies have shown that size, surface area, surface chemistry, solubility, and possibly shape all play a role in determining the potential to cause harm

  8. Research on Health Risks Studies in workers exposed to aerosols of some manufactured or incidental microscopic and nanoscale particles have reported adverse lung effects including lung function decrements and obstructive and fibrotic lung disease

  9. CNT Specific Research CNTs may contain metal catalysts as byproducts of their production, which could contribute to their toxicity Regardless of the process by which CNTs were synthesized and the types and amounts of metals they contained, CNTs were capable of producing inflammation, epithelioid granulomas (microscopic nodules), fibrosis, and biochemical/toxicological changes in the lungs

  10. CNT Specific Research SWCNTs have been shown to produce adverse effects at mass doses at which ultrafine carbon black did not produce adverse effects. Both are carbon based but SWCNTs have a unique structure SWCNTs were shown to be more toxic than quartz, which is considered a serious occupational health hazard if it is chronically inhaled

  11. CNT Specific Research MWCNTs have been shown to produce lung lesions similar to those observed in studies with SWCNTs These results indicate that, if CNT particulates reach the lung in sufficient quantity, they will produce a toxic response

  12. CNT Specific Research These studies do not answer the important health risk question of whether airborne CNT particles can reach the lungs, because in all cases the CNTs were placed inside the lungs of animals, not inhaled

  13. CNT Specific Research • The lungs aren’t the only organ affected by CNTs • Studying the effects on mouse hearts, scientists found damage to the DNA, an increase of plaque in the aortic area, and an increase of atherosclerotic lesions in the brachiocephalic arteries

  14. CNT Specific Research The risk of nanotubes is often compared to that of asbestos Exposure to asbestos is not the same exposure that could occur with CNT’s. According to Lance Criscuolo, president of Zyvex Performance Materials, an Ohio-based company that uses CNTs, “CNTs, once mixed into a polymer matrix, are bound up and no longer releasable into air or water.”

  15. CNT Specific Research This means the workers in most concern are the ones actually creating the CNTs and putting them into plastics The EPA is most concerned with the fibrous, dry powder and less concerned with CNTs that are integrated into polymer materials, said David Burton, General Manager, Applied Sciences Inc.

  16. CNT Specific Research Criscuolo said Zyvex has done air monitoring studies throughout the entire process. “These studies were performed by a certified company. They were not able to detect any significant amount of CNTs in the airstream. This testing was also included in the composite cutting and sanding area. This provides some solid evidence that once CNTs are encapsulated within a resin system, that they are not able to become free from that system.”

  17. How Can Workers Be Exposed • Inhalation • This is the most common and most dangerous type of exposure • It has been determined that the factors that have a role in pulmonary toxicity include, but are not limited to: • particle number and size distribution • dose of particle to target tissue • surface treatment on particles

  18. How Can Workers Be Exposed • the degree to which engineered nanoparticles aggregate/agglomerate • surface charge on particles • particle shape and/or electrostatic attraction potential • method of particle synthesis – i.e., whether formed by gas phase or liquid phase synthesis and post-synthetic modifications, which likely influence aggregation behavior.

  19. How Can Workers Be Exposed • Ingestion • Nanoparticles may enter the gastrointestinal tract as they are cleared from the upper respiratory tract and they appear to pass through relatively quickly • It is known that some nanoparticles, specifically nanotubes and nanofibers, can undergo surface oxidation and length shortening in presence of strong acid conditions, so it is possible that the acidic gastric environment will not only be unable to destroy the nanoparticles, but it may functionalize and shorten the particles to a point that their toxicological effect on the surrounding environment might change drastically

  20. How Can Workers Be Exposed • Dermal • Some studies show that nanoparticles may penetrate the skin due to their small size. This possibility is being investigated

  21. Can Nanoparticles Be Measured? • Traditional industrial hygiene sampling methods can be used to measure airborne nanoparticles • Scientists are developing more sensitive and specific sampling techniques

  22. Can Nanoparticles Be Measured? Workers need the development of sensors that simultaneously detect airborne nanoparticles and determine their potential to generate reactive oxygen species- possibly providing early indications of harm

  23. Airborne Exposure Limits These materials are used in the production of the CNT’s

  24. Controlling Exposure • Employers should use engineering controls to reduce workers exposure to nanoparticles • Source enclosure • Isolating the generation source from the worker • Local exhaust ventilation systems • Exhaust ventilation systems that use HEPA filters are effective in removing nanoparticles • (See next slide)

  25. Controlling Exposure Prevent food and beverages in workplaces where nanomaterials are handled It’s a good idea to systematically evaluate exposure to ensure that control measures are working properly and that workers are being provided the appropriate personal protective equipment

  26. Controlling Exposure • Existing U.S. regulations do not specifically address nanomaterials • The EPA apparently intends to designate CNT releases into US waters as a “significant new use,” which would likely trigger a major amount of additional compliance record-keeping for companies • For a specific examples of a protocol for handling of nanotubes see: • PROTOCOLS FOR HANDLING NANOTUBE COMPOSITES.doc • C-nano Material Safety Data Sheet.pdf

  27. Government Regulations EPA is issuing significant new use rules (SNURs) under section 5(a)(2) of the Toxic Substances Control Act (TSCA) for two chemical substances which were the subject of PremanufactureNotices (PMNs). The two chemical substances are identified generically as multi-walled carbon nanotubes (MWCNT) (PMN P–08–177) and single-walled carbon nanotubes (SWCNT) (PMN P–08–328). This action requires persons who intend to manufacture, import, or process either of these two chemical substances for a use that is designated as a significant new use by this final rule to notify EPA at least 90 days before commencing that activity. EPA believes that this action is necessary because these chemical substances may be hazardous to human health and the environment.

  28. Government Regulations • Exclusions include: • After they have been completely reacted (cured); • Incorporated or embedded into a polymer matrix that itself has been reacted (cured); or, • Embedded in a permanent solid polymer form that is not intended to undergo further processing except for mechanical processing.

  29. Safety Equipment • Personal Environmental Monitors can detect the amount of nanomaterials in the air that a worker is exposed to • This is crucial in the production of nanomaterials • Examples of PEMs

  30. Safety Equipment • Inhalation and ingestion protection can be provided by respirators • Must be(NIOSH)-approved air-purifying, tight-fitting full-face respirator equipped with N100 filters) • Ingestion protection can be aided by frequent washing of the hands and maintaining a clean work environment • Dermal penetration can be prevented by the use of nitrile gloves and full-coverage lab coats

  31. Cleanup and Disposal • Accidental spills of nanotubes are inevitable during their production, and the massive use of nanotubes-based materials could lead to increased environmental pollution • Research is being conducted to help aid in this situation • Scientists have found that CNTs deteriorate when exposed to the natural enzyme horseradish peroxidase, also called HRP • Once fully developed the method could be administered as easily as chemical cleanups in today’s labs

  32. Cleanup and Disposal The use of HEPA filtered vacuums and/or wet wiping techniques should be use often to keep the workplace clean Workers must wash hands frequently Setting up conforming hazardous waste management practices is a good idea

  33. Conclusion All in all, nanotechnology is a fun and exciting new science With all new technology comes risks It is recommended to take a prudent approach to manufacturing and to minimize exposure until more information available

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