Units will be metric. Manufacturers will define the functional unit for each LCA that includes a unit of time. The functional unit of flooring for carpeting could be 'product-life impacts per meter2' or 'impacts per meter2-year'. LCAs that use different functional units cannot be directly compared. The SPPC will assist manufacturers in defining a functional unit for their product.

The SPPC will require that all LCAs include the entire life cycle phases of the product from cradle to grave, including: extraction phase, materials processing phase, manufacturing phase, use phase, end-of-life phase and transportation among all phases.

The SPPC prefers original inventory profile data instead of averaged inventory profile data. Manufacturers will be required to specify what percent of inventory profile data is original and what percent is taken from industry averages. Percentages will be calculated from the numbers of entries in the inventory.

The SPPC requires the following ten impact categories that will be characterized in the LCIA.

1. Global Warming
2. Acid rain
3. Smog
4. Stratospheric ozone depletion
5. Water eutrophication
6. Indoor air quality
7. Human toxicity
8. Ecological toxicity
9. Habitat alteration
10. Resource depletion (fossil fuel)

Equivalent Characterization Units. The following equivalency units will be used for midpoint LCIA of each of the 12 categories

1. Climate change: CO2 equivalents
2. Acid rain: Hydrogen ion equivalents
3. Smog: Maximum Incremental Reactivity equivalents
4. Stratospheric ozone depletion: CFC-11 equivalents
5. Water pollution/eutrophication: Phosphate equivalents
6. Indoor air quality: Total VOC emissions (for floor coverings, VOCs are "combined" with amount of styrene-butadiene adhesive usage)
7. Human toxicity: For non-carcinogens, toluene equivalents. For carcinogens, benzene equivalents
8. Ecological toxicity: Ecotoxicity equivalents
9. Habitat alteration:
10. Resource depletion: Natural resource depletion equivalents

Solid and hazardous waste information will also be included in the report from the manufacturer. They will be reported separately from characterized environmental impacts to address US legal interests and to avoid double counting of impacts.

Solid waste	kg waste/ functional unit
Hazardous waste*	kg hazardous waste/ functional unit.

* document 40 CFR Part 261.42, outlines the legal framework for these materials.