The carbon footprint is calculated using primary activity
data and secondary data. Primary activity data is defined
as quantitative measurements of activity from a product’s
life cycle that, when multiplied by the appropriate
emission factors, determines the greenhouse gas emissions
arising from a process (British Standard Institution,
2011).
Secondary data is defined as data obtained from sources
other than direct measurement of the emissions from
processes included in the life cycle of the product (British
Standard Institution, 2011).