Life Cycle Impact Assessment (LCIA)

Life Cycle Impact Assessment (LCIA) is the third phase of Life Cycle Assessment (LCA) as described in ISO 14040 Standard.

The overall purpose of an LCIA is to assess the Product System from an environmental perspective using impact categories and category indicators connected with the Life Cycle Inventory (LCI) results to better understand their environmental significance.

The LCIA phase models selected environmental issues – impact categories – and uses category indicators to condense and explain the LCI results.

Key features of LCIA are:

  • providing a system-wide perspective of environmental and resource issues for one or more product system(s)
  • assigning LCI results to Impact Categories. For each Impact Category, the category indicator is selected and the category indicator result, hereafter referred to as Indicator Result, is calculated.
  • providing information on the environmental issues associated with the inputs and outputs of the product system based on a functional unit.

Category indicators are intended to reflect the aggregate emissions or resource use for each Impact Category.

The following list specifies Impact Categories addressed by ISO 14040 standard to be considered by LCA studies:

  • Climate change (the Greenhouse effects increasing the earth surface temperature due to release of carbon dioxide, methane, CFCs, etc., which in turn causes polar melt, soil moisture loss, deforestation, etc.)
  • Ozone depletion (the release of CFCs destroys the stratospheric ozone layer, leading to higher ultraviolet radiation and, in turn, to decrease in crops harvest, skin cancer, etc.)
  • Acidification (the release of sulphur dioxide and nitrogen oxides leads to acid rain, resulting in forest dying, damages to soil nutrients, damages to buildings, etc.)
  • Eutrophication (the air pollutants, waste water and fertilization in agriculture enriches nutrients in water and land, resulting in algae growth in waters, fish dying due to lowered oxygen concentration, and plants prone to diseases and pests, etc.)
  • Photochemical oxidants (the release of volatile organic compounds and oxides of nitrogen produces compounds that react with sunlight producing photochemical smog, which in turn leads to harmful impacts on human health and vegetation and reduced visibility).
  • Depletion of fossil energy resources
  • Depletion of mineral resources

In addition, LCIA prepares for the life cycle “potential environmental impacts” interpretation phase.