5.1 A nano-object at any specific time can be considered well-defined.

5.2 The life-cycle of a nano-object can be viewed as a series of production processes that transforms starting materials or a well-defined nano-object into a new, equally well-defined nano-object.

5.3 Each step of the life-cycle can be considered a separate production action and can be described by the information categories and descriptors within this guide.

5.4 The following are examples of nano-object productions that can be described by this guide.

5.4.1 The creation of carbon nanotubes by arc discharge.

5.4.2 The coating of a nano-object in a random or controlled manner when placed in a liquid.

Note 1: The reactivity of nano-objects makes it likely that even with the utmost precautions, various features and characteristics may change over time, for example, when a nano-object is placed in a liquid and coated. Such a coating can significantly change the properties, functionalities, and reactivity of the nano-object. This change can be considered one step of a life-cycle and is a production process.

Note 2: A nano-object may have more than one coating. For example, titania nano-objects are often coated by alumina by manufacturers to control certain properties. When these previously coated nano-objects are placed in liquid containing biological molecules, they can acquire a second coating. It can require very careful administration of test procedures to ensure the test results can meaningfully be ascribed to characteristics and features of the "initial" nano-objects.

5.4.3 A nano-object experiences changes to its size, shape, physical structure, and other characteristics.

Note 3: Events such as shock (unexpected forces), temperature and pressure changes, humidity changes, shipping, dissolution, and exposure to acids and bases can result in a changed nano-object with significantly different properties, functionalities, and reactivity. These events can be considered a production process.

5.4.4 Unless care is taken to carefully control potential changes to a nano-object before testing, measurement results should be carefully examined for unintended changes through good laboratory practices, statistical analysis of all data, and verification that test samples maintain their integrity throughout the testing process.

5.5 A nano-object can be subjected to a series or sequence of production steps. The steps can be fully planned and controlled or some steps can happen due to random events. This guide is applicable to describe one, many, or all steps in detail.

Note 4: For example, the testing of a nano-object for potential toxic effects may involve a sequence of steps as shown in Table 1. As can be seen, steps such as storage, insertion into biological media, or sampling can possibly involve random changes to the resulting nano-object.

5.6 Use of this guide to describe the individual production steps leading to the creation of a tested nano-object can be important in ascertaining the cause-effect relationship between a test result and a nano-object that was made in one of the sequence production steps prior to creation of the tested nano-object.

5.7 The reactivity of individual and collections of nano-objects gives rise to questions about their stability under "non-reactive" conditions such as movement, temperature changes, exposure to heat, and shock. These occurrences are frequent enough in the life cycle of nano-objects that additional information categories and descriptors should be used as detailed in 6.2.

5.8 ISO TC 229 has produced ISO/TS 80004-1:2010(en) that defines terminology applicable to nanomanufacturing.

5.9 Information on quality control with respect to the production process or production results is covered by ASTM and ISO quality control guides.