In Evonik, the environmental impact of products and technologies are quantified in the form of footprints and handprints. Therefore, it is necessary to connect life cycle inventories to environmental impact categories. In this context, Evonik uses up-to-date characterisation factors. The main environmental mid-point indicators considered are outlined below.
describes the depletion of abiotic resources, such as zinc ore and crude oil, thus lowering their availability for future generations. The ADP of metals and minerals (or simply ADP of elements - unit is kg Sb equivalents) and the ADP of fossil fuels (unit is MJ) are distinguished.
measures water sourced from ground or surface bodies and thus causing freshwater depletion in kg. A process's blue water inventory includes all freshwater inputs less rainwater. It includes the sum of blue water consumed while the scarcity of water in the specific region is not considered
measures nutrients emitted to ecosystems. Emitted nutrients contain nitrogenous and phosphorous compounds that accelerate biological activity, leading to undesirable shifts in species compositions. This in turn can result in a depressed oxygen level and may lead to a collapse of an ecosystem. The Eutrophication Potential (EP) is expressed using the reference unit kg PO4 equivalent.
is a relative measure of how much heat a greenhouse gas traps in the atmosphere, leading to climate change. It compares the amount of heat trapped by the mass of a greenhouse gas (e.g., methane) to the amount of heat trapped by a similar mass of carbon dioxide over a defined period (100 years). GWP is therefore expressed as a factor of carbon dioxide in kg CO2 equivalents.
is the depletion of ozone in the stratosphere of the earth leading to increased fractions of solar UV-B radiation arriving at the earth’s surface. This increased UV-B radiation may harm human and animal health as well as ecosystems. Ozone Layer Depletion Potential is measured in kg CFC-11 equivalent.
is the measure of substances (e.g. nitrogen oxides and volatile organic compounds) emitted to the atmosphere, forming photo-oxidants (e.g. ozone) in the presence of sunlight. Whereas in the higher atmosphere, ozone protects against ultraviolet (UV) light, low level ozone is implicated in diverse negative impacts such as crop damage, increased incidence of asthma and other respiratory complaints. Photochemical ozone creation potential is expressed using the reference unit kg C2H4 equivalents.
is a measure to depict the amount of primary energy required. It considers all efficiencies and losses throughout a process chain and sums up the energy of all primary energy carriers needed. The Primary Energy demand is measured in MJ (net calorific value).
are also considered. These include Acidification, Ecotoxicity, Human Toxicity, Ionizing Radiation, Land Use Impacts, Particulate Matter, Water Scarcity, and Resource Use, to mention but a few.