Generally - if the nanoparticle is hazardous to health (either due to its size or the chemical nature of the nanoparticle) then the user/population must be protected from exposure.

The precautions required depend on the nature of the nanoparticle and how its being used. At the moment you're asking a really broad question, which can't be answered with a few bullet points - but below I've put some _very_ general guidelines

Prevent inhalation of the nanoparticles - preferably by containing the source of the nanoparticles. Only as a last resort should protective preventative equipment/clothing be used to prevent problems.

Prevent ingestion of the nanoparticle (again, by containment of the source.

Lower concentration of the nanoparticle (for example by dilution)

Use the largest nanoparticle possible (look at data on the size of particles which remain trapped in the lungs compared to the sizer of particles which don't make it into the lungs and/or are exhaled)

I agree with Smail.

I agree with Fiona Smail to explain the precautions but i want to explain some health problems.

Nano-material can be inhaled, swallowed, absorbed through skin, injected during medical procedures, may enter the bloodstream from the lungs and translocate to other organs, including the brain. Many metal and metal oxide NP’s have shown genotoxic or carcinogenic effects, systemic cadiovascular effects, detrimental effects on the cells with which they come into contact to DNA breakage and oxidation, mutations, reduced cell viability, warped morphology and decreased proliferation. Studies using primary or cultured human skin cells have shown that carbon nanotubes can enter cells and cause release of pro-inflammatory cytokines, granulomas, and pulmonary fibrosis, oxidative stress, and decreased viability. Engineered radioactive nanoparticles have applications in medical diagnostics, medical imaging, toxicokinetics, and environmental health, and are being investigated for applications in nuclear medicine produced many health problems . Titanium dioxide (TiO2) dust is considered a lung tumor risk.

I find a photo-link which explain the diseases associated to nano-material exposure.

I agree with the above answers and it is really difficult to answer this broad question. Potential and severity of risk varies from materials to materials. In general all metal based nanoparticles are harmful for health. It is better to use protection while dealing with any kind of nanoparticles.

You can go through these articles:

http://www.tandfonline.com/doi/abs/10.1080/13698570701306807?journalCode=chrs20

https://phys.org/news/2007-04-nanoparticles-dna-cancer.html

We theoretically investigated the effect of nanoparticles on the point mutations of DNA. Practically for all types of nanoparticles a mutation is possible (see my publications)

Hi,

The characteristics of nanoparticles that are relevant for health effects are:

Size: In addition to being able to cross cell membranes, reach the blood and various organs because of their very small size, nanoparticles of any material have a much greater surface to volume ratio (i.e. the surface area compared to the volume) than larger particles of that same material. Therefore, relatively more molecules of the chemical are present on the surface. This may be one of the reasons why nanoparticles are generally more toxic than larger particles of the same composition.

Chemical composition and surface characteristics: The toxicity of nanoparticles depends on their chemical composition, but also on the composition of any chemicals adsorbed onto their surfaces. However, the surfaces of nanoparticles can be modified to make them less harmful to health.

Shape: Although there is little definitive evidence, the health effects of nanoparticles are likely to depend also on their shape. A significant example is nanotubes, which may be of a few nanometres in diameter but with a length that could be several micrometres. A recent study showed a high toxicity of carbon nanotubes which seemed to produce harmful effects by an entirely new mechanism, different from the normal model of toxic dusts.

Please you refer the following link

ec.europa.eu/health/ph_risk/committees/04_scenihr/docs/scenihr_o_003b.pdf

Yes. There are a lot of published research regarding risk and exposure of nanomaterials. Importantly, Material Safety Data Sheets (MSDS) for nanomaterials are in the developing stage. There are no threshold values in many sections of MSDS (such as physicochemical properties, Toxicological information and so on) which should be harmonised and acceptable by the Governments and standard scientific community worldwide. Therefore, a robust techniques for developing control binding chart in a lab is still challenging to create. Hopefully, we will have complete MSDS for all nanomaterials near future.

Thank you everyone for sharing your valuable explanations.