Nanoparticles have distinct features that make them valuable for a wide range of industries. But these tiny particulates also come with their share of health hazards and therefore have occupational hygienists at work to keep them in check.
In this blog, we will define nanoparticles, their process of generation, health hazards, the assessment process, and Exposure Standards in place.
What are Nanoparticles?
Particles with dimensions between 1 and 100 nm are called nanoparticles. 1 nanometer (nm) is 1 billionth of a meter and is 500 times smaller than the diameter of human hair.
Definitions of Nanoparticles
Based on their size, the nanoparticles are defined as given below:
1) Nanoparticles – 3 dimensions < 100nm
2) Nanofibres – 2 dimensions <100nm
3) Nanoplatelets – 1 dimension <100 nm
Besides, when the primary nanoparticles come together they are referred to as given below depending upon their interconnecting bonds:
- Agglomerates – Weakly bound particles
- Aggregates – Strongly bound particles
NOAA – Nano objects and their aggregates and agglomerates
European Commission recommended definition Recommendation (2022/C 229/01) of Nanomaterials is:
Natural, incidentally formed or manufactured material constituted of solid particles:
- as an unbound or individual particles
- as an identifiable constituent particle in aggregate or agglomerate
- At least 50% of these particles (individual or constituent) in the numerical size distribution have one or more external dimensions between 1 nm and 100 nm.
However, it should be noted that a material with a VSSA (Volumetric Specific Surface Area) < 6 m²/cm3 is not considered a nanomaterial.
Types of Manufactured Nanomaterials
Nanoparticles are divided into many categories based on their size, shape, physical and chemical characteristics. Carbon-based nanoparticles, ceramic nanoparticles, metal nanoparticles, semiconductor nanoparticles, polymeric nanoparticles, and lipid-based nanoparticles are a few examples.
Some of the types of Nanomaterials that are manufactured are as given below:
1. Carbon-based
Fullerenes, carbon nanotubes, graphene, and carbon dots are examples of these materials. Because of their electrical conductivity, high strength, structure, electron affinity, and adaptability, these materials are very appealing.
2. Metal
They are entirely composed of metal precursors. These have distinct optoelectrical qualities due to their well-known localised surface plasmon resonance (LSPR) features.
3. Ceramic
Researchers are interested in these inorganic non-metallic solids because of their usage in catalysis, photocatalysis, dye photodegradation, and imaging applications.
4. Semiconductor
Semiconductor materials exhibit qualities in between metals and nonmetals, as well as broad bandgaps. Bandgap tuning causes considerable changes in their characteristics. As a result, they are crucial materials in photocatalysis, photo optics, and electrical devices.
5. Polymers
Many approaches have been developed by scientists to synthesise polymeric nanoparticles for a variety of applications such as surface coating, sensor technology, catalysis, and nanomedicine.
6. Lipids
These NPs have lipid moieties and are employed as medication carriers in a variety of medicinal applications (the mRNA Covid-19 vaccines are using lipid nanotechnology). In gene therapy, lipid nanoparticles are also viewed as extremely promising techniques for delivering nucleic acids
Besides, nanoparticles are present in Aluminium Oxide, Titanium Dioxide, Synthetic, Amorphous silica, Cerium Oxide, and Zinc Oxide
How are Nanoparticles generated?
Natural and anthropogenic are the two primary sources of nanoparticles.
Natural nanoparticles have been present on Earth for centuries due to wind erosion, dust storms, volcanic activity, and biogenic sources.
Large amounts of anthropogenic nanoparticles have recently been discharged into the environment, both purposefully and inadvertently.
Nanoparticles are being utilised as insecticides and fertilisers, as well as for water and soil clean-up. They are used in numerous items nowadays due to their unique features compared to bulk equivalents.
Accidental nanoparticle release happens due to a rising number of nanoparticle-containing goods and a by-product of incomplete combustion caused by cars and industries.
Uses of nanomaterials
Nanoparticles are incredibly tiny particles that are fewer than 100 nanometers in size. They are employed in a variety of applications like as medication administration, medical imaging, water purification, and consumer goods. Nanoparticles have unique physical and chemical characteristics due to their tiny size, making them valuable for a wide range of applications. They can, for example, be used to deliver medications directly to particular cells in the body, which can increase therapeutic efficacy and lessen adverse effects.
They may also be utilised to manufacture more efficient and effective water filters, as well as more effective sunscreens and other consumer items. Overall, nanoparticle utilisation is a fast-expanding subject with several potential uses.
Health Effects of Nanoparticles Exposure
The health effects of nanoparticles depend on the size of their particles; the smaller the size, the larger the surface area and the greater the chance of exposure to biological factors.
The particles enter the body through various routes like inhalation, ocular route, ingestion or oral absorption, and dermal absorption, with inhalation being the most common one.
Certain tiny nanoparticles can settle down in the alveoli and lead to inflammation and respiratory diseases.
The key health effects of exposure to and inhaling the nanoparticles are as given below:
- Total death rate is increased
- Rise in the fatal rate caused by respiratory and cardiovascular diseases
- damage to the heart and lung functioning.
- Pulmonary inflammatory effects
- Interruption in blood coagulation
Nanoparticles Exposure Assessment
Test methods
Measuring exposure – Metrics to be used Standard EN 16966
1. Direct Reading Real-time
Depending on the equipment, direct reading measures might be time and size based. Postponed measurements might be universal or specific in nature. They can be size-based by utilising cascade impactors.
2. Time-based Measurements
Time-based measurements involve identifying high-exposure periods or incidents, considering ambient noise and intensity monitoring.
3. Size-based Measurements
Gives data about the aerosol’s particle size distribution.
4. Time and size-based measurements
The time and size-based measurements involve the monitoring of high-exposure phases or events and provide Granulometry data.
5. Real-time Measurements
They involve the use of different instruments like Partector, P-track, Grimm, etc. to measure direct exposure readings in real-time.
It should be noted that the size distinguishing instruments provide data on the agglomerates’ sizes rather than constituent particles.
Hence, one should select the measuring instrument based on the size range (agglomerates and/or isolated particles) and the predicted concentration.
a) Optical Particle Counters
It involves the measurement of optical diameter measurement and particle counting.
b) Condensation Particle Counters
Principle: Light scattering / Detection by increasing particle size by
vapour condensation on the surface
6. Deferred Measurements
Deferred measurements are calibrations that are postponed and might be global or specialised. They might be based on size.
It involves the sampling of the Respirable fraction and the Cascade impactor and the laboratory analysis depending on the chemical composition of the particles.
Assessment Strategy of Nanoparticles
The assessment strategy for analysing the exposure to nanoparticles has 3 stages:
1. Initial Assessment stage
This stage involves onsite visits to analyse and measure static points and the review of documents. This phase highlights the presence of nanoparticles at the workplace location.
2. Fundamental Exposure Evaluation
This stage involves the basic evolution of exposure to the nanoparticles. It involves individual real-time measurements, which is a combination of the sampling process and laboratory analysis. During all these processes, the light protocol is followed.
3. Complete Evaluation of Exposure
In this third stage, advanced protocols are followed. Here individual real-time measurements are done against multiple metrics. It also involves sampling and laboratory analysis, which is repeated for each metric.
Exposure Standards for Nanoparticles
There are no worldwide regulations for limiting nanoparticle exposure. Many nations, including Australia, have legislation in place to safeguard employees and the general public from potentially dangerous compounds, such as nanoparticles. These rules may include occupational exposure limits (OELs).
Occupational Exposure Limits (OELs):
It describes the maximum concentration of a material to which a worker is permitted to be exposed, as well as instructions for the safe handling and disposal of nanoparticles. Employers must be aware of and follow these requirements to guarantee the safety of their employees and the general public.
Anitech’s Precautionary Tips
Anitech’s Occupational Hygienists have some precautionary tips for workers who handle or are exposed to nanoparticles.
We recommend workers wear proper personal safety equipment such as gloves, masks, and eye protection for the following:
- To limit the danger of inhaling nanoparticles, work in a well-ventilated location.
- To avoid the discharge of nanoparticles into the air, use a fume hood or other containment device.
- To avoid ingestion, keep nanoparticles away from food and drink.
- To avoid skin contact, avoid touching your face or lips when dealing with nanoparticles.
- For correct handling and disposal of nanoparticles, follow the manufacturer’s recommendations.
- To avoid contaminating the environment, use caution while disposing of nanoparticles.
- To prevent particle accumulation, clean and maintain equipment used to handle nanoparticles on a regular basis.
You can drop an enquiry here
For further advice, you can also ring us at 1300 802 163 or email at info@anitechgroup.com
Our Occupational Hygienists will be happy to help!
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