4.1 Natural and manufactured textiles fibers can be treated with chemicals to provide enhanced antimicrobial (fungi, bacteria, viruses) properties. In some cases, silver nanomaterials may be used to treat textile fibers (1).6 Silver nanomaterials are used to treat a wide array of consumer textile products, including but not limited to various clothing; primary garments (shirts, pants), outer wear (gloves, jackets), inner wear (socks and underwear), children’s clothing (sleepwear); children’s plush toys; bath towels and bedding (sheets, pillows); and medical devices (wound dressings) (2).
4.2 There are many different chemical and physical forms of silver that are used to treat textiles and an overview of this topic is provided in Appendix X1.
4.3 Several applicable techniques for detection and characterization of silver are listed and described in Appendix X2 so that users of this guide may understand the suitability of a particular technique for their specific textile and silver measurement need.
4.4 There are many different reasons to assay for silver nanomaterials in a textile at any point in a product’s life cycle. For example, a producer may want to verify that a textile meets their internal quality control specifications or a regulator may want to understand the properties of silver nanomaterials used to make a consumer textile product under their jurisdiction or what quantity of silver nanomaterial is potentially available for release from the treated textile during a washing process. Regardless of the specific reason, a structured approach to detect and characterize silver nanomaterials present in a textile will facilitate measurements and data comparison.
4.5 The approach presented in this guide (see Fig. 1) consists of three sequential tiers: obtain a textile sample (Section 7), detection of a silver nanomaterial (Section 8), and characterization of a silver nanomaterial (Section 9). If no forms of silver are detected in a textile sample using appropriate (fit for purpose) analytical techniques then testing can be terminated. If silver is detected but present in a non-nanoscale form, the textile can be treated as a bulk material; however, there still may be potential for release of silver ions that transform into nanoscale silver-containing particles. If silver is detected in nanoscale form it can be concluded that it is a silver nanomaterial in the textile sample and subsequent measurements can be made to characterize its chemical and physical properties.
4.6 Numerous techniques are available for the detection and characterization of silver nanomaterials in textiles which can cause confusion for those interested in developing an analytical strategy and selecting appropriate techniques. Some techniques are applicable only to certain chemical forms of silver a......