Safety and Health Assessment of Manufactured Nanoparticles in Nano-coated Textile Products

Textiles and Light Industrial Science and Technology

Oct. 2012, Vol. 1 Iss. 2, PP. 37-42

Safety and Health Assessment of Manufactured Nanoparticles in Nano-coated Textile Products Jun Chen *1, 2, a, Yan-guang Lu3, b, Cheng Sun1, c 1

School of the Environment, Nanjing University, Nanjing 210093, China

2

Suzhou Entry-Exit Inspection & Quarantine Bureau, Suzhou 215104, China

3

Jiangsu Entry-Exit Inspection & Quarantine Bureau, Nanjing 210001, China

*a

chen.jun.ciq@gmail.com; benvidean@nju.edu.cn; c 13705170715@vip.163.com

Abstract- Many nanotech-based fabrics products and

critical or even most important characteristics of nanomaterials that drive their toxic profiles. Very little information is available on how the various physical and chemical properties interact to generate an overall toxicity picture for a particular product. Specifically, there has been very little attempt to use standard particles to study individual characteristics and how these may interact, nor to attempt to develop quantitative structure activity ratios (QSARs) [1].

applications are already in use for textile finishing process in many countries. The industry aims at taking advantage of the opportunities of new nanomaterials while producing safe and ecological textiles. However, some concerns have been raised regarding the potential of engineering nanoparticles may have a negative impact on human health and the environment.

Up to now there are only few toxicological research and safe assessment done on the release of engineered nanoparticles from such products. This article summarizes the coping strategies and risk management of some developed countries and outlines the necessity of prospect research and risk assessment of nanotechnology potential hazards and technical uncertainty of nano-coated textiles to the environment and public health. The author believes the responsive regulations will allow for prevention and treatment of a nano-textiles’ life-cycle risks and support the safe, responsible development of nanotechnology while providing favorable conditions for textile industrial innovation to ensure that research and technological development are translated into affordable and safe wealth-generating products and processes.

Unique properties of these materials could have significant implications for basic components of the traditional paradigm for informing risk management decisions: hazard identification, exposure and dose-response assessments, and risk characterization [2, 3].

Under these circumstances, an assessment of risk and appropriate safety measures based on the available limited data on nanomaterials characterization and safety protocols are needed to protect human health and the environment [4].

The success of promising new nanotechnologies in textile industries will turn on public confidence, built on science-based transparent regulation. It is generally agreed that the ability to precisely measure and predict the effects of nanomaterials on the safety, health, and the environment during life span of the nano-coated textiles will ensure human safety and enhance quality of nano-coated fabrics [5, 6].

These best practices will provide guidance on EH&S and engineering control and workplace administration to minimize human and the environment exposure to nano-coated textiles and during manufacturing processing.

The development of practical guidelines and risk assessment within the value chain from producers to consumers will help textile industries and the authorities to identify applications with associated risk, and to take the necessary safety precautions.

Keywords- Nano-Coated Textiles; Nanosafety; Nano Risk

I. INT RODUCT ION Nano-finished fabrics are coming onto the markets globally with enormous speed. Various nanometer composite emulsion and its multifunctional finishing technology have been applied in fabric dyeing and finishing.

Numerous references in the literatures are now available, and highlight the various applications of NT for the textile industries. This treatment is applied to giving textiles the desired handle, to making further processing easier and to improving the thermal and antistatic properties. Nano finishing is concerned with positive control and processing technologies in the sub nano meter range and so must play an essential role in the fabrication of extremely precise and fine parts. The properties imparted to textiles using nanotechnology include water repellence, soil resistance, wrinkle resistance, anti-bacteria, anti-static and UV-protection, flame retardation, improvement of dye ability and so on.

II. NANOTECHNOLOGY TEXTILE PRODUCTS AND NANO-SAFETY ISSUES As an “enabling technology�, nanotechnology could open the way for the use of textile products outside their traditional fields with significantly improved or even completely new functions [7]. Due to the advancement of nanotechnology in the manufacturing of fibers/yarns as well as in the development of fabric finishes, the applications and

However, there appears to be little consensus over the

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Oct. 2012, Vol. 1 Iss. 2, PP. 37-42

scope of nano-technology in the area of textiles are widespread. Several methods can apply coating onto fabrics, including spraying, transfer printing, washing, rinsing and padding. These research endeavors are mainly focused on using inorganic nanosize powders and generating nanostructures during finishing processes (Tab. 1). Using nanotechnology, the treatments are enough to attach to

individual fibers, delivering superior performance characteristics without compromising the look, feel or comfort of the fabric [8]. Nanotreatment let fabrics to obtain special properties like: anti-microbial, anti-UV, self-cleaning, nanocapsules of moisturizing agents, deodorizing, repellent, and others.

T able I FUNCAT IONAL FIBER/FABRICS WIT H INORGANIC NANOMET ER-POWDER Nano-Composite Functional Fibe r/Fabrics

Inorganic Nanome te r-Powde r

Antibacterial Fibers

Ag, Ag-Zr, Ag-Zn, Ag-Cu, ZnO, T iO2

Anti-ultraviolet Fibers

T iO2 , ZnO, Al2 O3 , SiO2

Far infrared fiber

ZrC, ZrO, Al2 O3 , MgO, Cr 2 O3 , Sn doped T iO2

Magnetic fiber

Fe2 O3 , Ferrites, Zr 30 Fe35 Ni35 Rare Earth Oxides

Conductive fiber

Carbon Black, CuI 2 , Sb doped SnO2 , T iO2 , ZnO, CuS

Changeable colored fibre

Cobalt and nickel chloride, Complex Compound

Anti-static fibre

Sn doped T iO2 , Sb doped SnO2 , Carbon Black

Ultra-high moisture absorbing fiber

CaCO3

Flame resistant fiber

SnO2 , Mg(OH) 2 , Al(OH) 3

Although a number of nano-coated textiles are already available on the market, it is questionable whether the environment and human health could be affected by unintended release of engineered nanomaterials (ENMs) during their product life cycle(production, transport/storage, use, and disposal/recycling) [9]. However, the type and quantity of EMNs applied in textiles have not been optimized, and the mechanisms of functionality may not be entirely understood. There were not enough data about the exposure and the effects of nanparticles release from nano-coated on fabrics surface. From an environmental point of view, nanotechnology probably includes both chances and risks.

On one hand, nanotechnology could provide an alternative to the integration of potentially hazardous chemical additives (e.g. flame retardant substances) or lead to more environmental friendly production methods. On the other hand, various non-governmental organizations (NGOs) have expressed their concern about possible effects on human health trough the exposure to ENMs, potential environmental impacts and the lack of regulatory measures.

Nanoparticles Dermal

Ingestion

Inhalation

Injection

GI Tract Lymphatic System

Respirator Tract Blood Circulation

Neurons

Central Nervous System

Nervous System

Organs Fig. 1 Route of human exposure to nanoparticles

Nano-safe policy is still searching for the adequate approaches about how to deal with engineering nanomaterials in dying process. There is a need to build research capacity to be able to understand the more fundamental aspects of the properties, toxicokinetics, and fate and behaviour of nanomaterials in the environment, to be able to develop models for the prediction of impacts and to design new materials that are inherently safe to human health and the environment, specifically [14]:

Recently what investigations carried out show some concerns have been raised regarding the potential of some MNs may have a negative impact on the environment. Some in-vivo and in-vitro studies at laboratory-level have provided indications about the hazardous potential of certainnanoparticles. Previous research has suggested that nanoparticles may pass unobstructed through natural barriers and membranes into the body and distribute in the various organs and tissues through four prominent exposure routes of nanoparticles: inhalation, ingestion, skin absorption, and injection routes (Fig. 1). The bioaccumulation of nanoparticles in secondary target organs and dose-response relationship were observed after the uptake of nanoparticles via inhalation, oral or dermal administration [10, 11, 12, 13].

–Validation of in vitro tests against in vivo models.

–A paucity of primary cell models against which to validate various immortalized cell lines.

–A lack of studies on animals other than rodents (rats, mice and hamsters) as well as flawed studies on humans.

This makes it impossible to determine safety factors in extrapolating from animals to humans. A lack of studies on human disease also makes it very difficult to assess the safety factors to be used to take account of vulnerable groups (e.g. children, elderly, diseases and genetic variations in susceptibility).

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–A clear understanding of the pathways of systemic uptake from epithelial surfaces, factors determining distribution and organ uptake, tissue metabolism, particle sequestration and excretion.

to define risks and provide standard operating procedure for safe handling of ENMs. The interdisciplinary research on ENMs has formed a multidisciplinary consortium of internationally recognized researchers with unique and extensive experience to address nanoparticle risk issues which cover the following areas:

–Most nanoparticles will accrue biological products on their surface on contact with a living system (e.g. surfactant, serum proteins). Advantage is taken of such biological coatings in the targeting of nanoparticles for medical uses e.g. monoclonal antibodies. However, very little is known on the influences of adsorbed naturally occurring proteins and lipids on transport and subsequent toxic effects of most types of nanomaterial.

–Creating accurate measurement and globally-accepted standards for nano-coated textiles; –Identifying exposure scenario and risk level with the view of environmental and health effects; –Providing framework conditions for responsible handling of engineering nanoparticles during dyeing;

–The relationship between cell uptake and subsequent toxic effects on a cell or tissue. This especially applies to concerns over cancer, neurodegeneration and fibrosis. Of particular importance is a clearer understanding of those properties of particles that enhance toxicity as opposed to simple uptake, the cellular compartments involved and species differences in these.

–Promoting public dialogue about the promise and risks of nanotechnology.

In order to determine the exact health and environmental impact stimulated by ENMs, their entire life cycle needs to be accessed. It is now nearly universally accepted that the product life cycle is the proper perspective for thinking about ENMs released from nano-coated fabrics of textile products [18]. The product life cycle of nano-coated textiles determines in what life cycle phases and in what environmental compartments or in what technological facilities MNs are released. In the context of the extraordinarily high uncertainty that is currently characteristic of nanotechnology, comparative approaches to LCA that emphasize analysis within a specific decision context may have greater utility than attempts to establish life cycle properties on an absolute basis.

–Small animals (rodents) may not be optimum for studying the long term toxic effects of nanomaterials, although greater effort should be focused on using strains that are especially susceptible to specific toxic effects and species that live longer including pigs, sheep and non-human primates.

–Toxicology studies using the more complex nanomaterials are required with some attempt at prioritisation of those materials in most need of assessment.

Although attempts have been made to assemble a cassette in vitro and in vivo to serve as a tiered approach to toxicology screening for consumer products like nanotechnological textiles or garments, these have largely been based on classical toxicology tests [6]. The laboratory-scale research on risk assessment of nanoparticles has not yet been sufficiently scaled up to understand the potential environmental implications of high-yield manufacturing of nano-coating fabrics. Because the synthesis, purification, and separation processes employed in manufacture of nanomaterials and nanotreatment of textiles can result in important changes in the nanomaterials characteristics, these processes cannot be assessed independently of the end-use application [15].

Surface properties, functionalization, interaction with environmental media, and microbial activation may all play roles in nanoparticles toxicity that cannot be captured in terms of mass (or volume) concentration.

A typical LCA includes some midpoints that relate to human or ecotoxicological health. Characterization of toxicological midpoints depends on the relation of source terms (as embodied in the life cycle inventory) to health midpoints, relative to selected benchmarks. Characterization factors depend on the fate and transport of the chemical in the environment as well as the relationship between a biological dose and a health response. Finally, all LCA data must be referenced to an appropriate functional unit representing the demand, activity, or product that is the purpose of the nano-coated production system. Life cycle assessment (LCA) has been a holistic tool to assess products and systems, but current knowledge about the development of nanoparticle environmental impacts is too scarce to be included for application within the LCA framework. The safety issues presented by nanotechnology make impact assessment within LCA so difficult that the normalization and weighting steps are often simply ignored.

Therefore, the strategy for risk assessment of ENMs should take life cycle concepts into consideration and vice versa in order to mitigate the situation of having only limited knowledge on the risks inherent in ENMs.

Nanoparticles unintentionally released from nano-coated textiles may come into direct contact with humans and end up in ecosystem [16]. The ultimate release load and release rate of inorganic nanoparticles from commercial textile products during their life cycle into the environment might present a potential risk to the ecological system [17]. To prevent potential hazards and risks from unintentionally releasing of ENMs on nano-coated fabrics, timely targeted research on nanopartical exposure and hazardous assessment is needed

A. Nanomaterial-control Strategies Nanomaterials in textile products have presented unique challenges when assessing possible short and long term

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toxicity in humans and yet with the exponential growth of new nanomaterials and their application to the end-products.

It is essential that these challenges are met by a robust scientific and regulatory strategy that minimizes cost and use of animal testing and still provide sufficient reassurance to the public and workers who encounter these materials to ensure they are adequately protected [20]. In case of such a production systems exposure during nano-textile life span, a thoughtful case-by-case risk analysis is required with potentially hazardous nanomaterials and a proactive risk-management system has to be established [16].

Although toxicological studies will improve understanding nanoparticles, it is highly unlikely that all the possible ENMs permutations or combinations (including functionalization) can be tested or modeled with standard methods and tools developed in the field. Empirical testing, which is limited with regard to conventional chemical classes, will never be sufficiently informative of the range of possibilities in regard to nanomaterials.

Nanotechnology has exerted its influence not only on making versatile fiber composites but also on making upgraded chemical finishes. Nanoparticles such as metal oxides and ceramics are also used in textile finishing to alter surface properties and to impart textile functions. The most effective way to minimize nanoparticle exposure or nanotechnology risk for nano-coated textile products is to implement effective control strategies on the basis of a good understanding of the nanomaterials and nanotechnology uncertainty [23].

Several governmental agencies and regulatory bodies have started programs and initiated activities to address the human health and environmental risks and benefits of nanotechnology. On supranational level the Organization for Economic Cooperation and Development (OECD) and the International Standardization Organization (ISO) have installed working groups and intensified their activities in the field of coping with potential risk of nanotechnology issues in the health, legal and social area. Some distinct efforts were identified to develop and deliver a systematic and disciplined process for identifying, managing, and reducing potential environmental safety and health risks of engineered nanomaterials across all stages of a textile’s life cycle. Until specific regulations like REACH and TSCA are developed, these regulations will not provide government and industry bodies with a strong framework for ensuring that engineering nanomaterials are manufactured and used in a manner that protects against unreasonable risks to human health and the environment.

Some of the most common production procedures for nano-coated textiles which are currently under investigation are pointed out in order to give indications about the form in which the nanopaticles could be presented in the fiber matrix of the finished fabric [21]. This includes conducting an extensive research on the manufacturing, storage, distribution, application and disposal of the nano corpuscles.

Of these methods, exposure assessment and quality characterization of nano-coated fabrics are required to support decisions on appropriate controls that might be necessary for the textile industries and related products containing engineer particles. However, it is uncertain what measurement technique should be used to monitor exposures at different stages of product life cycle.

C. Risk management and quality nano-coated textile products.

assurance

of

Risk assessment is an essential preliminary step to determine what control level must be implemented to limit emissions in the environment and prevent a toxic substance from uncertain nano-coated textile products to public health and the environment [24]. Nano product safety evaluations should be undertaken and integrated in the existing safety and quality policy throughout the supply chain management and life span evaluation. It is generally agreed that Risk Management should be integrated into the existing safety and quality culture of companies.

In the case of nanoparticles unintentionally released from nano-coated textiles, the sections on health risks and occupational exposure have clarified the serious lack of knowledge in these two fields essential to the assessment of danger or risk [22]. The following general requests and concerns of the stakeholders were put up. These can be seen as background to clarify the positions and attitudes towards regulation.

–Pollution spill from a nano dyeing treatment facility;

The most effective measures to ensure safety and quality of nano-coated textiles is an elaborate risk assurance management system like ONR 49000 ‐O N R 49 FERMA (UK), AS/NZS 4360:2004 (Australia/New Zealand), in which necessary categories of preventive and restrictive measures are taken in relation to the marketing and use of nano-products posing a serious risk to the health and safety of consumers. In view of the rapid advances in knowledge in occupational health and safety, Nano risk assessment like CENARIOS® was developed in close contact with the requirements of industry and includes requirements for risk evaluation, risk monitoring, communication and knowledge management. It will assume a good knowledge of the identity and toxicity of nano-textile products and reduce the risk may

–Nanoparticle manufacture workers develop chronic illness; –Nanoparticles leach from nano-coated textiles to accumulate in the environment; –Product recall due to research findings indicating nano-coated textile product is a hazard; –Liability claims on a company, directors and officers regarding nano-coated textiles indicated by research to be unsafe, but subsequently released to the consumer market.

B. Principles for a responsible handling and use of nanomaterials.

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include withdrawal from the market or recall from consumers.

with nanotechnologies, but it must be clear that retailers cannot be made responsible alone for all nano-based product related issues. A safety matrix like voluntary measures by the industry will help business and the authorities to identify applications with associated risk, and to take the necessary safety precautions for nano-finshing textile products [27].

D. Good practices and test guidelines.

To evaluate and address the potential risks, the control strategies give recommendations of what studies are required to determine the health and environment hazards and exposure [25]. Occupational health surveillance is an essential component of an effective occupational safety and health program for nanomaterial exposure, but guidance needs further work for use on engineering nanomaterials.

The use of good work practices can help to minimize worker and consumer exposures to nanomaterials. Furthermore, the development of a comprehensive impact and risk analysis framework require tests of properties, toxicity, description of use and exposure.

The major challenges of voluntary measures in the area of communication of nano-finishing technology risks lie in a lack of a common understanding. Because the extent of exposure to nanomaterials in currently available commercial products is relatively unknown, voluntary measures like CoC or voluntary labeling schemes for verifying and declaring compliance with all existing legislation applicable can express the realization of industry's individual responsibility.

This information deficit makes evident that the voluntary measures like CoC can only act as a first step in improving the really needed discussion within the stakeholders. Due to the absence of binding definitions and regulations, a guideline is assumed to be necessary. First worldwide rules for a possible declaration of Nano products will be worked out by ISO groups, but they will not be available so soon.

OECD and ISO are in charge of developing uniform terminology, nomenclature and standardized methods of measurement and testing in the areas of health, the environment and safety. In September 2006, OECD established “Working Party on Manufactured Nanomaterials” (WPMN) under chemical committee. This working party organized occasionally meeting in order to exchange information and create international network. The working party composed of 6 steering groups which are:

III. CONCLUSIONS Transparency and risk communication becomes more and more necessary to consider the way of managing textile industrial activity and related risks related to nanotechnology. Potential toxicity of ENMs and resulting risks has recently attracted significant attention of regulatory agencies and stakeholders. Regulation specifically for nano textiles is under development with stakeholders in nanotechnology having opinions ranging from the belief that “nano-specific regulation is not needed” to those who believe that there is a regulatory void that could harm both human health and the economic stability of the nanotechnology industry. Therefore, there is an urgent need for more international collaboration to accelerate the process of risk assessment under LCA frame. The combination of evolving toxicological knowledge with life cycle concepts could mitigate the uncertainty about the effects of ENMs on human health and the environment, and answer at an early stage some basic questions about decision making in the innovation and regulation processes and thus foster safe and sustainable development of the new technology.

Multilateral efforts to create scientific building blocks for risk assessment of engineering nanomaterials applied in finishing process could offer a fundamental understanding of any potential human health and environmental risks resulting from exposure throughout the product life cycle of nano-coated textiles. We believe experts will benefit from understanding the underpinnings of public perceptions about science, and learning about the topics the public most want to be informed about. When citizens perceive that scientists take their concerns into account, this promotes greater public trust in the relevant actors and institutions.

The extent to which nanotechnology will impact our lives only depends on the limits of human genuinely.

SG1: Development of research database; SG2: Environment, health and safety (EHS) research strategy on manufactured nanomaterials; SG3: Safety testing of a set of representative manufactured nanomaterials; SG4: Manufactured nanomaterials test guidelines; SG5: Co-operation prevention;

on

voluntary

schemes

and

SG6: Co-operation on risk assessment and exposure measurement.

One important condition for above regulation is the presence of validated and standardized methods to measure and to test the properties of synthetic nanoparticles, including the toxicological properties. The involvement of industry, authorities and the public in the debate on opportunities and risks must be an integral part of technological development.

E. Voluntary or mandatory labeling.

There are presently several standardization organizations working on voluntary environmental safety and health standards [26]. Voluntary measures by the industry may be sufficient to add warning labels on the product or to improve the use instructions for ensuring product safety. The Swiss Retail Association (IG DHS – Interessengemeinschaft Detail handel Schweiz) published a Code of Conduct (CoC) Nanotechnology in April 2008. The CoC of the IG DHS is a first and important step on dealing

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ACKNOWLEDGEMENT

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The authors thank the Public Sector Special Scientific Research Program of AQSIQ (2007GY10-60) and the Suzhou Institute of Nanotech and Nanobionics (SINANO) of Chinese Academy of Science (CAS) for their generous hospitality while doing this research.

[13] O. Renn, C. Roco. Journal of Nanoparticle Research, Vol. [14] [15]

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