Life cycle thinking

Goal and scope

According to the ISO 14040 standard, the first phase of an LCA is the goal and scope definition. The goal defines the purpose of the assessment and its intended application and audience. The scope provides a detailed product-system description where the  system boundaries of the assessment are determined in terms of technological, geographical and temporal coverage. This also includes outlining the functional unit (FU) as a benchmark for comparison, specifying data requirements, and identifying crucial modelling assumptions and constraints in relation to the study’s goal (Finnveden et al., 2009).

This phase of an LCA serves as the foundation upon which experts precisely outline the systems under scrutiny. Here, initial decisions are made that define the LCA's working plan (Bruijn et al., 2002). 

Goal

The goal should explicitly and transparently mention the purpose of the study. This includes:

• What needs to be done in the study (e.g. a hotspot analysis to prioritise impact-reducing actions, a comparison between products/systems, or other applications);

• The motivations behind conducting the study;

• Intended application and users.

If you are conducting an LCA for a pharmaceutical product, a hotspot analysis might reveal that the use and distribution phases have the most substantial impact on climate change and water resource depletion for example (Zampori et al., 2016). This information can guide manufacturers in making improvements in that particular phase to reduce the product's overall environmental footprint (Thomassen et al., 2019).

The goal also states if the study includes “comparative assertions intended to be disclosed to the public” (ISO, 2006). These are environmental claims that one product is superior over a competing product that fulfills the same function (Bruijn et al., 2002). 

Scope

The scope defines the depth and detail of the study, showing that the study can address the stated goal. It can be adjusted throughout the study, however, it needs to be well defined, ensuring accurate breadth and reaching the required level of detail matching with the goals and objectives set earlier. To match those specifications, the definition of the functional unit and system boundaries are fundamental characteristics to go further with the study (Jolliet et al., 2015).

Functional unit

The functional unit (FU) is a measurable parameter that serves as a reference unit of a product system (Finnveden et al., 2009). The FU is essential to understand environmental impacts. The climate change impact of a car could be stated as 120 grams of CO2 equivalents, or 50 tonnes of CO2 equivalents. Without the respective FUs of 'per kilometer' and 'per vehicle lifespan', the information is meaningless and not comparable between products and studies. It is essential to note that the FU must be a quantifiable attribute of the product or process (Jolliet et al., 2015; European Commission, 2010; Thonemann et al., 2020).

Concerning pharmaceuticals, a mass-based FU could be selected (e.g. 'per kilogram'), and that might be appropriate for studies comparing the environmental impact of two manufacturing processes that result in the same product with equal properties. However, for broader applicability and specific insight into the impact of medicines, an effect-related FU is required to evaluate the environmental impact of a pharmaceutical product. This could be one 'defined daily dose' (DDD) of the medicine, or the treatment of a specified number of patients with a particular condition or disease in a certain region and within a given time-frame, dependent on the system boundaries (Siegert et al., 2019).

System boundaries

The life cycle of a pharmaceutical product has well defined stages. Raw materials are mined and harvested, active pharmaceutical products (APIs) are manufactured, the medicine is formulated and distributed, the treatment is administered and excreted into the environment where eventually it is degraded. The figure below depicts all life cycle stages that an LCA practitioner can take into account for a holistic assessment of a pharmaceutical product (Van Wilder et al., 2024). 

System boundaries are established to clarify which of the unit processes of the system will be included in the LCA. The system boundaries shall align with the study's objectives  (ISO, 2006). For instance, if the goal of an LCA for a new pharmaceutical product is to identify potential hotspots in climate impact throughout its whole life cycle, a system boundary and a functional unit that only takes the production phases into account is not sufficient. The varying size of system boundaries can generally be categorised into four types (de Haes, 2001):

• Cradle-to-gate: 'Cradle' refers to the beginning of the life cycle (raw material extraction), and 'gate' can literally mean the front gate of the factory. Therefore, this scope option usually only includes production/manufacturing prior to the use of a product. This small system boundary is convenient for manufacturers conducting a LCA because all activities are controlled by them and easily understood. Distribution and sales might also be included (prior to use).

• Gate-to-gate: Like cradle-to-gate but only operations within the manufacturing plant are considered (i.e. ignoring raw material extraction). This might be an appropriate study to help optimise processes and energy use.

• Cradle-to-grave: 'Grave' refers to the ultimate fate of a product after use, therefore cradle-to-grave covers the entire supply chain of a product or service, including the use of the product and waste management and its impact on the environment if released in wastestreams.

• Cradle-to-cradle: Taking a circular economy approach, reused or recycled products can be considered 'cradle-to-cradle'. This can account for open loop recycling where materials are recycled into different products from what they were used for originally, which then effects what the most appropriate functional unit might be.

A problematic with the cradle-to-gate terminology is that the 'gate' is interpreted differently among studies. For pharmaceutical products, some LCA practitioners identify the gate as belonging to the factory. Others see the last step before use (e.g. prescription) as the gate of their system. Therefore, Siegert et al. (2019) have attempted to standardise system boundary terminology for APIs (as in the figure below).

It is good practice to represent the system boundary visually to indicate the included and excluded systems. A flow diagram offers a comprehensive overview of the processes and their inter-dependencies. It illustrates each unit process included in the system and defines the flows that connect these unit processes. The flow diagram is constructed starting from the reference flows and then identifies the first-tier intermediary flows related to each reference flow (Jolliet et al., 2015). To take one example, in a publication from Rentería Gamiz et al. (2019), an illustrative flow diagram was developed showing a cradle-to-gate process for the production of infliximab (a treatment for autoimmune diseases), divided into three different levels: process level (α), plant level (β) and overall industrial level (γ).