https://www.researchgate.net/profile/Md_Karim6/publication/265128652_Too_enthusiastic_to_care_for_safety_Present_status_and_recent_developments_of_nanosafety_in_ASEAN_countries/links/5405be460cf23d9765a72cd6.pdf

hope this helps you.

Article Too enthusiastic to care for safety: Present status and rece...

According to quantum mechanics, the energy levels in atoms or

molecules are not continuous, but discrete. Hence there is a well

defined gap between the valence band and the conduction band. This

is called as the ‘electron band gap’ and is an important concept to

understand many phenomena associated with the nanomaterials.

The band gap is expressed in terms of electron volts (eV) which is a

very small unit signifying the energy acquired by an electron

accelerated across the potential difference of 1 volt.

The lager the band gap, the greater the difficulty for the valence

electrons to jump to the conduction band. This explains poor

electrical conductivity of non-metals (insulators). Whenever there is

an overlap of valence and conduction bands, the electrons can move

across freely into the conduction band as happens in the case of

metals (conductors). If the band gap is narrow, the electrons can be

elevated to the conduction band with small amount of energy. Such

materials are semiconductors.

The concept of band gap is also useful in understanding the

interaction of light with matter. The band gap is a useful predictor of

wavelength of light that will absorbed by the material. This

relationship is inverse. The narrow band gap materials can absorb in

the high wave length visible range due to lower energy requirement

for transition of the electron into the conduction band. The large band

gap materials absorb in the short wavelength UV region due to the

high energy required by the valence electrons to jump across a wide

gap to the conduction band. The semiconductors have a very narrow

band gap of 1~3 eV and these generally absorb in the near UV region

(UV A&B).

Band gap is the intrinsic property of the material. However, in the

nanoscale region there is an alteration in the band gap and the

dependant propertie

Dear Andrea Spinazzé 

Greetings,

Please find the attached file about your topic may be useful for you.

Best Regards,

Yes dear

According to the my practical knowledge, there are three different researches schools ,German, English and Swiss made well practical assessment for nanomaterials hazards and prevention actions from their impacts on occupational safety and public health. The Swiss school assessment was contains a details to classify the degree of expected hazard into three levels Nano 1, Nano 2 and Nano 3.

Figure (1) and (2) shows schemes after answering the questions to determining the level of the risks, and what action to take for minimizing and\or avoiding their impacts. Table (1) of Hampshire University contains a set of questions,  leading to quantify the risks without pointing to the protection requirements for these risks.

The protective measures of the exposure risk to nanomaterials were organized in four trends for all risks levels Nano 1, Nano 2, Nano 3. These trends are connected to technical aspect, organizational, personnel and finally the workplace cleaning. Table (2) and (3) and (4) and (5), respectively shows  better detail for the limits of these trends representing  the latest , clearer and more comprehensive requirements on which the requirements of occupational safety for the prevention are designed. Also content  a set of steps that would prefer to follow.

Thank you 

[German school]

The Federal Institute for Occupational Safety and Health (BAuA), "Guidance for Handling and Use of Nanomaterials at the Workplace", German, 2007.

[English school]

 University of New Hampshire,"Nanomaterials Safety Program", UK, 2009.

[Swiss school]

Groso A., Alke P.F., Magrez A., Riediker M.and Meyer T., "Management of nanomaterials safety in research environment", Part. Fibre Toxicol, 7:40, 2010.

Thank you for your prompt and exhaustive replies.

Andrea

Andrea:

CSA Z12285 provides guidance on setting up an exposure control program for engineered nanoparticles.  Exposure assessment and risk management are elements within the program, but I suspect you are looking for a more detailed document to help you do exactly that.  CSA has developed complimenting standards to Z12285 to help workplaces perform exposure assessments and risk management.  I have attached the scopes of each for simplifying your decision.

CAN/CSA-ISO/TR 13121:13 Nanotechnologies – Nanomaterial Risk Evaluation

1 Scope

This Technical Report describes a process for identifying, evaluating, addressing, making decisions about, and communicating the potential risks of developing and using manufactured nanomaterials, in order to protect the health and safety of the public, consumers, workers and the environment.

While the overall product stewardship and risk management process set forth in this Technical Report is not unique to nanomaterials, it supplements recognized approaches by providing, where possible, a focus on information and issues specific to nanotechnologies. It offers guidance on the information needed to make sound risk evaluations and risk management decisions, as well as how to manage in the face of incomplete or uncertain information by using reasonable assumptions and appropriate risk management practices. Further, it includes methods to update assumptions, decisions, and practices as new information becomes available, and on how to communicate information and decisions to stakeholders.

This Technical Report suggests methods organizations can use to be transparent and accountable in how they manage nanomaterials. To that end, it describes a process of organizing, documenting, and communicating what information organizations have about nanomaterials. This includes acknowledging where information is incomplete, explaining how information gaps were addressed, and explaining the rationale behind the organization's risk management decisions and actions.

And CAN/CSA-Z12901-2:15 Nanotechnologies — Occupational risk management applied to engineered nanomaterials—Part 2: Use of the control banding approach

1 Scope

The purpose of this part of ISO/TS 12901 is to describe the use of a control banding approach for controlling the risks associated with occupational exposures to nano-objects, and their aggregates and agglomerates greater than 100 nm (NOAA), even if knowledge regarding their toxicity and quantitative exposure estimations is limited or lacking.

The ultimate purpose of control banding is to control exposure in order to prevent any possible adverse effects on workers’ health. The control banding tool described here is specifically designed for inhalation control. Some guidance for skin and eye protection is given in ISO/TS 12901-1.[19]

This part of ISO/TS 12901 is focused on intentionally produced NOAA that consist of nano-objects such as nanoparticles, nanopowders, nanofibres, nanotubes, nanowires, as well as of aggregates and agglomerates of the same. As used in this part of ISO/TS 12901, the term “NOAA” applies to such components, whether in their original form or incorporated in materials or preparations from which they could be released during their lifecycle. However, as for many other industrial processes, nanotechnological processes can generate by-products in the form of unintentionally produced NOAA which might be linked to health and safety issues that need to be addressed as well.

This part of ISO/TS 12901 is intended to help businesses and others, including research organizations engaged in the manufacturing, processing or handling of NOAA, by providing an easy-to-understand, pragmatic approach for the control of occupational exposures.

Control banding applies to issues related to occupational health in the development, manufacturing and use of NOAA under normal or reasonably predictable conditions, including maintenance and cleaning operations but excluding incidental or accidental situations.

Control banding is not intended to apply to the fields of safety management, environment or transportation; it is considered as only one part of a comprehensive risk management process.

Hope this helps.

The Dutch RIVM has nanomaterials as one of their focuses. See https://www.rivm.nl/bibliotheek/rapporten/2014-0157.pdf