Cellulose can be found in woody plants, non-woody plants (grass, algae ), bacteria, and waste; generated from forestry, timber industry, agricultural practices or industries, or even paper pulp industries and cities (Li, 2015; Rajinipriya, 2018; Ramesh, 2017) The plant cell has two different parts, an external thin layer, as a primary source. And, in the inner side of the plant, there is the cellulose microfibril, as a secondary source. The microfibrils are composed by elementary nanofibrils. The latter are extracted from the former and result in nanocellulose.
The nanocellulose can be classified by different methods (Nechyporchuk et al., 2016; Osong, 2016; Tayeb, 2018; Yang et al., 2019):
·From top-down processes one can get cellulose nanocrystals (CNC) and nanofibrillated cellulose (NFC)
·From bottom-up processes one can obtain bacterial cellulose (BC)
On the other hand, special attention has been focused on the search for the extraction of nanocellulose from raw materials (Suhas et al.
, 2016; Tervahartiala et al., 2018). So, few of them are thinking in recycled materials from waste (Rajinipriya, 2018). Cotton is an excellent cellulosic fiber as it content 85-90% of cellulose and their fibers are so long, between 18 to 25 mm, and it does not have lignin, it means it is easy to extract for nanocellulose.
So according with several studies is the highest rate as pure fiber if it compares with the most common natural sources (Brinchi et al., 2013; Howard et al., 2015; Li, 2015; Ramesh, 2017; Sixta, 2013). Although, the production of raw cotton is also an impact to the environment (Carlin, 2019; Li, 2015; Quintana et al., 2015; Suhas et al., 2016). Few studies consider the extraction of nanocellulose from recycled cotton for packaging (Abdolali, 2014; Suhas et al., 2016).
At some point, some studies (Brinchi et al., 2013; Rajinipriya, 2018) have found that the extraction process of NFC consumes a lot of energy. One possibility is extract the nanocellulose by acid hydrolysis that is has less impact in the energy consumption (Li, 2015).
5. Regulations and certifications
In order to prevent or reduce the problem of waste packaging in e-commerce, the institutional environmental policies should apply competent regulations for the waste management in business and the consumers behaviour (Jorgensen, 2013; Manerba et al., 2018). This review is attempt to introduce the main legislations from the European Union, the ISO related with the Life Cycle Assessment, the Carbon footprint affected by the transportation and Forest Stewardship Council related with sustainable forest.
5.1. E.U. legislation
Pira International in 1997 determines the new rules for packaging in the 21th century, by this time the EU Directive on Packaging and Packaging Waste (94/62/EU) (European Parliament, 1994) established several measures to control the packaging waste and the concept of recycling (Sturges, 2000). It means to get 50-65% to recover the packaging waste and to achieve 25-45% of recycled packaging. It means to be achieved by 2001. Over time this legislation was amended by 2008 (European Parliament, 2008) to add new recycling and recovery targets to be achieved by 2020: 50% preparing for re-use and recycling of certain waste materials from households and other origins similar to households, and 70% preparing for re-use, recycling and other recovery of construction and demolition waste(European Commission, n.d.). The same EU Directive commission considers that the best option to not generate as much waste is to try to minimize the production of the packaging and the reduction of the materials that it includes (Monnot et al., 2019).
ISO 14040 defines LCA as a tool to evaluate the environmental conditions and potential impact, as global warming, acidification, ozone depletion and others, related with a product or service through its life cycle (ISO, 2006). In the case of packaging, the analysis should considers the guidelines methodology (European Commission, 2010; Wolf et al., 2012): the inputs as the raw materials and energy related with the material extraction, primary material production, packaging manufacture, logistic, use, and end-of life. And it should be considered to evaluate the outputs, considering the atmospheric emissions, by-products or other wastes that generates the impacts on the environment.
ISO 14067 is also another alternative method to analyse the environmental impacts based on Carbon footprint of products. (Hohenthal et al., 2019) considers this approach as a complement to ISO 14040 for report an open loop recycling of paper products.
5.3. Carbon footprint (CF)
Carbon footprint studies the control of carbon dioxide emissions to the atmosphere. (Jorgensen, 2013) considers transportation one of the most important impact on the environment with the emissions of CO2, Co, NO and HC. Boosting business in e-commerce is also generating the increase of mobility in freight transport, and as a consequence in packaging waste. For this reason, it is necessary to take into account actions such as recycling all the material generated by these commercial activities and trying to reduce the amount of packaging material. For this achievement the Directive 94/62/EC on Packaging and Packaging Waste consider to implement several rules (Wikstrom, 2010). Furthermore, it is important to choose the right material in order to decrease the amount of it for improving the transport efficiency, but maintaining the certainty that the product does not break. On the other hand, applying ISO14067 (Hohenthal et al., 2019) allow to evaluate the Carbon footprint of products applying principles, requirements and guidelines for the qualification and communication of the carbon footprint of a product (CFP), based on International Standards on life cycle assessment (ISO 14040) and on environmental claims, labels and declarations (ISO 14020) (ISO, 2012). Several studies has been evaluated the impact of the emissions in the atmosphere by the freight transport and the alternatives solutions to reduce them (Cairns, 2005; Carling, 2015; P?lsson, 2017; Rizet, 2010; Seebauer, 2016; Smidfelt Rosqvist, 2016; Van Loon, 2015; Wiese, 2012). The present review will be considered for the study of a material that allows with less volume better performance for less waste and CO2 emissions. Another interesting aspect to consider is to save breakage in the products.