Journal of Minerals & Materials Characterization & Engineering, Vol. 9, No.5, pp.455-459, 2010 Printed in the USA. All rights reserved
Safety and Risk Associated with Nanoparticles - A Review
Vinita Vishwakarma 1*, Subhranshu Sekhar Samal 1 & N. Manoharan 2
1Centre for Nanoscience and Nanotechnology
(A Joint Initiative of IGCAR, Kalpakkam & Sathyabama University, Chennai)
2Sathyabama University, Chennai, India-600119
*Corresponding author:
The emerging field of nanotechnology has created risk for environment and human health.
Nanoparticles are not a recent discovery. It has existed for many years. Today synthesis of
nanoparticles takes place for many applications in various field of science, technology,
medicine, colloid technologies, diagnostics, drug delivery, health impacts, food, personal care
applications etc. In spite of this, toxicology of nanoparticles is poorly understood as there are no
sufficient methods to test nanoparticles for health, safety and environmental impacts, especially
in the size range lower than 50nm.
Key Words: Nanosafety, nanoparticles, nanotoxicity, health and risk, environmental impact
The behavior of nanoparticles is relatively different from larger particles of the identical
material. There is a correlation between a decrease in particle size and an increase in toxicity,
because of larger surface area. The ability of nanoparticles to penetrate deep into our respiratory
system and their better assimilation in the body fluids make them unique.
The nanoparticles are likely to be unsafe for the biological system. The research on toxicity of
nanoparticles indicates that some of these products may enter the human body and become toxic
at the cellular level in the tissues and organs [1, 2]. The materials of these particles may or may
not be carcinogenic or allergic but even inert nanoparticles show harmful effects due to some
absorbed toxic species or formation of toxic products due to reactions with body fluids. Some
456 Vinita Vishwakarma, Subhranshu Sekhar Samal & N. Manoharan Vol.9, No.5
nanoparticles may show enhanced catalytic properties to generate highly reactive forms of
oxygen that can cause tissue injury including inflammation and other toxic effects. For air born
particles, this injury can translate into asthma and atherosclerotic heart diseases.
The impact of nanoparticles interactions with the body is dependent on their size, chemical
composition, surface structure, solubility, shape and how the individual nanoparticles accumulate
together. Due to small size and hence higher specific surface area of the nanoparticles, these can
easily bind with and transport toxic pollutants, which when inhaled can cause a number of
pulmonary diseases in mammals. Inhaled nanoparticles have the ability to translocate in the body
as much as 80 % of the deposited mass. Once the nanoparticles enter the body, these can travel
freely in the blood throughout the body and reach the organs like liver or brain. It can get deeper
into the lungs and bloodstream may cross the blood-brain barrier Skin contact could easily occur
during handling of the nanoparticles.
According to the Berkeley proposal, lower sized (<10nm) nanoparticles behave more like a gas
and can pass through skin and lung tissue to penetrate cell membranes. Once inside the cell, they
might become toxic or disrupt normal cell chemistry. Threadlike nanotubes are structurally
similar to asbestos fibers, which can cause lung fibrosis when inhaled in large amounts over long
periods, according to a report by the Royal Society, the United Kingdom's National Science
Academy [3].
Though the nanoparticles are known to exist in the atmosphere in large concentrations (108/cc),
the release of manufactured nanoparticles into atmosphere and aquatic environment is yet
insignificant and unknown. But the scientific community has shown concern that nanoparticles
cause brain damage in aquatic environment [4].
Fullerenes & bucky balls, which are known to attract electrons, cause generation of damaging
free radicals [5]. Nanotoxicity studies of carbon-based materials as well as quantum dots have
been conducted. Literature shows that low-solubility ultrafine particles are more toxic than larger
particles on a mass for mass basis [6].
When we consider environmental exposure for nanoparticles, we may find that nanoparticles are
easily airborne and adhere easily to surfaces which are difficult to detect. Through the
environment nanoparticles may enter the food chain, influence the biosphere, influence structural
change in liquids like water (biogenic nanoparticles) and chemical/physical transition by
According to Nel (2006), some factors like particle size, chemical composition, surface structure,
solubility and shape influence the effect of nanoparticles on the body. Such particles can gain
access to the body through the gastrointestinal tract, skin and lungs. Nanomaterial may enter
inside the body though ingestion. Nel believes that toxicity screening plan for nanomaterials
Vol.9, No.5 Safety and Risk Associated with Nanoparticles 457
should have three key elements - physical and chemical characterization, tissue cellular assays
and animal studies.
It is necessary to do more research into the toxicity of nanoparticles because ultrafine particles
are more reactive and toxic in their effects. Preliminary studies have shown that some types of
nanoparticles could cause lung damage in rats [7].
Some of the organisation like National Institute of Occupational Safety and Health has started an
active program for studying the safe handling of nanomaterials in the workplace. How
workers are potentially exposed to nanomaterials and if so what are the characteristics and levels
of exposures and workers health? What work practices, personal protective equipment,
and engineering controls are available and how effective are they for controlling exposures to
nanomaterials? [8].
During manufacture and handling of these materials there may be a chance of release and
exposure of nanoparticles to workers which can get inside their body through inhalation, dermal
contact and ingestion routes [9]. Only limited information on the risks of handling of these
materials are available, so workers should implement strict control procedures and engineering
safety features to limit exposure when working with them and not to allow them to eat or drink in
the laboratory.
When workers handle the nanomaterials they should use laboratory safety practices such as
Personnel Protective Equipment (PPE) including gloves, lab coats, safety glasses, face shields,
closed-toed shoes etc avoid the skin contact with nanoparticles or nanoparticles containing
solutions [10]. If it is necessary to handle nanoparticle powders with exhaust laminar flow hood,
workers should wear appropriate respiratory protection. Use of fume exhaust hoods to expel
fumes from tube furnaces or chemical reaction vessels is very much crucial. Laboratory
personnel should be trained with the risk associated with workplace hazards, Material Safety
Data Sheets (MSDS), labeling, signage etc periodically.
Disposal of nanoparticles is also reflecting on the safety of the environment. It should be
according to hazardous chemical waste guidelines.
More research is required in this field as ultra fine particles could pose a human health hazard
[11]. Research is now showing that when harmless bulk materials are made into ultrafine
particles, they tend to become toxic. Generally, the smaller the particles (<10µm), the more
reactive and toxic are their effects.
458 Vinita Vishwakarma, Subhranshu Sekhar Samal & N. Manoharan Vol.9, No.5
If nano research helps us to understand the root causes of toxicity in these materials, then safer
materials can be engineered which can save to the human lives as well as dollars can be made.
Industry consortiums, environmental real data on toxicity into the iterative groups and individual
corporations need to take strong action to determine the safety of materials and products before
they reach into the market.
Today engineered nanomaterials also help in handling emergencies. Nanotechnology-based
sensors and communication devices can reduce their exposure to risk of injury. Nanosize
coupled with wireless technology may facilitate development of wearable sensors and systems
for real time occupational safety and health management. Nanotechnology-based fuel cells, lab-
on-chip analyzers and opto-electronic devices all have the potential to be useful in the safe,
healthy and efficient design. The development of high performance filter media, respirators,
dust-repellant, self-cleaning clothes, fillers for noise absorption materials, fire retardants,
protective screens for prevention of roof falls and curtains for ventilation control in mines,
catalysts for emissions reduction and clean-up of pollutants and hazardous substances may
support for nano safety.
Proper care should be taken about nanoparticles and nanotechnology safety issues for the
personal health and safety of the workers who are involved in the nanomanufacturing processes
and also the consumer to eliminate its effect on the environment.
[1] Champeau Rachel., Assessing safety, health risks of Nanomaterials, 2006, published: 15:05
EST, University of California - Los Angeles.
[2] Jin Y., Wu M. and Zhao X., Toxicity of Nanomaterials to Living Cells, University of North
Dakota, US, 274 – 277, 2005.
[3] DelVecchio Rick., 2006, Berkeley considering need for Nano safety,
[4] Rick Weiss, 2004, Nanoparticles Toxic in Aquatic Habitat, Study Finds, Washington Post
Staff Writer.
[5] Theresa Phillips., 2009, Are Nanoparticles Safe? Guide.
[6] Cincinnati, OH., Approaches to safe nano-technology: an information exchange with
NIOSH,2006a, Department of Health and Human Services, Centers for Disease Control and
Prevention, National Institute for Occupational Safety and Health. DHHS (NIOSH) ,
[7] Bullis Kevin., 2006, "Nano" Safety Recall: A product touted as “Nano” has hospitalized six
German consumers, prompting more warnings over the dangers of Nanomaterials,
[8] Schulte-PA; Salamanca-Buentello-F, Ethical and scientific issues of Nanotechnology
in the workplace, Environ Health Perspect 115,5-12, 2007.
Vol.9, No.5 Safety and Risk Associated with Nanoparticles 459
[9] Dreher L. Kevin., 2005, Health and Environmental Impact of Nanotechnology:
Toxicological Assessment of Manufactured Nanoparticles, Toxicological Sciences, 77: 3-5,
[10] Feder J. Barnaby., Health Concerns in Nanotechnology, 2004, The New York
[11] Peter HM Hoet., Irene Brüske-Hohlfeld and Oleg V Salata, Nanoparticles–known and
unknown health risks, Journal of Nanobiotechnology, 2:12 2004.