Sustainable Nanotechnology. Группа авторов

recently studied thermally rearranged polymers that are aromatic polymers containing heterocyclic rings. These polymers have excellent chemical and thermal stability due to the presence of microporous structures that are formed by thermal rearrangement in solid state, which makes it unique for transportation of gas for separation [71].

      2.3.9 Materials Supply and Utilization

Materials supply and its proper utilization is needed for industries in electronics due to their rapid growth. These electronic industries produce many e‐wastes, which are a serious hazard to the environment. Electronic materials generally contain resin and silica. Even resin contains 80% of silica. A huge amount of silica present in e‐waste is wasted. So, this silica from e‐waste is used to prepare porous molecular sieves that contain NMs. Thus, recycling resin from e‐waste can be a sustainable approach for the environment [72]. Liou et al. synthesized mesoporous silica with high purity and larger surface from resin ash having a pore size of 3 nm. This approach can minimize the disposal problem of electronic items, which is again a benefit for sustainable environment [72].

      2.3.10 Encapsulation of Fertilizers

      Fertilizers are generally needed in the soil for nutritional supplement for better growth of plants. Nowadays, mostly farmers use NPK fertilizer, which consists of nitrogen, phosphorous, and potassium. Due to the high solubility of NPK fertilizer, it is mostly lost in the environment due to rain.

      This approach of addition of fertilizer becomes costly to farmers and harmful to humans and the environment. Due to the advancement in nanotechnology nanofertilizers have been developed, which have the potential to increase the nutritional value of plants. It also has the tendency of slow delivery because the nutrients coated with NMs can control delivery [73]. One study showed that the presence of biosensor in nanofertilizers can control delivery depending on the need of the soil and the growth rate of plant. Singh et al. compared the bulk NPs of zinc oxide on the growth of cabbage and cauliflower. It was observed that compared to bulk ZnO particles, nanozinc particle is more effective in terms of germination growth and protein content [74].

      2.3.11 Regulatory Development

      The properties of NMs, i.e. extremely high chemical reactivity due to nano size range, large surface area, and narrow size range, make them hazardous to the environment and human health. The therapeutic NMs, which are prepared from all known inert materials, could become penetrable or react with the non‐targeted site and molecule, respectively. On one hand, the toxic manifestation of several NMs is still unknown, and on the other hand, the large‐scale production technology is growing at its peak. The exposure of NMs by such mass production industry can create unprecedented event. To anticipate and minimize unfavorable consequences or unintended consequences and to have future public acceptance of nanotechnology‐based innovations and development, robust regulatory guideline and support are required today.

      Appreciable initiatives are taken by different countries/states till date to regulate nanotechnology, NMs, and the production thereof, including Europe, United States, Asia, and all over the world.

      The European Commission has actively reacted on the issue, and under its guidance during 2011–2013, a detailed tactical research outline was published by the associates of the European Union (EU) NanoSafety Cluster with a strategic goal for future exploration on the secure utilization and safeguarded applications of all formulated NMs. The timeline for this documentation was kept for 10 future years starting from 2015. The document focused on delivering a key action ahead in the development of safe and sustainable NMs. Shortly after, the regulatory body of the European Chemicals Agency (ECHA) developed massive advice on the regulatory risk assessment under the European Community Regulation on chemicals and their safe use (REACH) for NMs and published it in April 2012. The European Union funded project BILAT USA 4.0 is one of the milestone events in the development of regulatory guidelines globally. In this event, one of the major concerns was the cooperation for nanosafety between the United States and EU. The result of the event was the identification of several prospective tools and five components for dedicated and accurate evaluations of human and environmental hazards caused by nanotechnology that includes improved testing assays, pertinent endpoints, technical awareness, risk assessment classification for NMs under development or in usage, and harmonized methods to toxicity evaluation.

      The US government has its own initiative for nanotechnology that is active since 2000 called the National Nanotechnology Initiative (NNI). NNI actively looks into all matters concerning the sustainability of NMs. The issues related to EHS implications of NMs are specifically taken care by two different groups, Nanotechnology Environmental and Health Implications (NEHI) and Nanoscale Science, Engineering, and Technology (NSET). The first one is the working group of the Nanoscale Science, and the second one is the subcommittee of the National Science and Technology Council. Under NEHI, the US government has been funding since 2005 for EHS‐related research.

      A persistent initiative taken by a conference in 2011 and the result of the conference was establishment of an organization – SNO – as discussed in previous section. The objective of SNO was set to support sustainability in nanotechnologies and support and promote further development of nano‐based formulations, taking into consideration health and environment. The SNO also aimed at the safe use of nanoproducts along with providing support for policy and decision‐making. The establishment of such organization made its impact all over the world.

An organization in Singapore working since 2004 was registered in 2007 as Asia Nano Forum (ANF) society to promote development, awareness, and safety of nanotechnology. One of the objectives of ANF is to encourage and harmonize standardization and well‐being of nanotechnology assessments. Including Singapore, 13 different organizations from Japan, Korea, Malaysia, Australia, Philippines, Taiwan, Thailand, and Vietnam are working under one roof for the sustainable development of nano‐based products. Similarly, in Canada, Switzerland, India, and Australia, several government, individual, and autonomous bodies are working hard to address the issues of development, sustainability, and promotion for end users. Although individual organizations are working in their best possible way, it is the need of the hour to unite all the efforts and to address issues arising in development, sustainability, and promotion for end users. Such united efforts can not only uniformly report on single desk but also minimize the time required for recording unknown toxicity of all NMs and related products.

      2.3.11.1 The Possible role of Standards in United Regulation

      1 Development of procedures for life cycle assessment (LCA) of nanotech‐based ingredients, devices, and products.

      2 Investigate and release risk assessment tools in the field of nanotechnologies and update it from time to time.

      3 Development and delivery of protocols for robust and unique toxicology study to measure toxicity of all different NMs on a single scale.

      4 Record all toxicological data on a single platform and update it from time to time.

      5 Identify and release robust industrial health protocols related to nanotechnologies and include all possible hazards related to the same occupational health hazards list.

      6 Support regulation in the area of nanotechnologies.

2.4 Conclusion

      Nanotechnology has appeared as a flexible technical solution to global sustainability challenges. The economic growth in the field of nanotechnologies will lead to an increased variety and increased volumes of engineered nanocarriers that are produced. Certainly, there are challenges for sustainability of nanotechnology itself. Threat of unknown and irreversible toxicity to human and environment is the major issue among them. The use of a life cycle assessment method, combined with risk assessment, to understand the potential problems and to implement green nanomanufacturing methods that are less troublesome to the environment and human health, is currently in progress. Considering the efforts made by different organizations all over the world, there is an opportunity to consider new universally agreed free‐of‐bias regulatory standards,