Comparative Life-Cycle Assessment of laundry detergent formulations in the UK. Part II: Time trend analysis and wash equivalent comparison (1988-2001)

This paper presents environmental profiles of various Procter & Gamble (P&G) laundry detergents in the UK over a time period from 1988 to 2001 using Life-Cycle Assessment (LCA). Detergent formulations studied are regular powder (RP), compact powder (CP), powder tablet (PT), dilute liquid (DL), compact liquid (CL) and liquid unit-dose (LT). The functional unit of the present study is 1 wash under representative conditions of formulation, packaging, wash habits and sewage treatment infrastructure for the respective years. The analysis shows considerable environmental improvements on most indicators within the powder and liquid category between 1988 and 2001. Key drivers behind these environmental improvements were reduced wash temperature and dosage. Reduced wash temperature was made possible through innovative technologies, improved formula design and washing machine improvements. Innovative manufacturing processes and improved formula design allowed for dosage reduction. Combining market share data for the different detergent formulations with corresponding LCA results leads to an environmental fingerprint of an "average" wash with P & G laundry detergents ("wash equivalent"). The evolution of wash equivalents over time clearly demonstrates a continuous improvement for all LCA indicators between 1988 and 2001.