Appendix A: Approximations

Assessment of the consequences of a possible ban on phosphates in household detergents

The amount of households in Denmark is approximately 2,532,000 (Statistics Denmark, 2007) and it is relevant to distinguish between households with one person and households of more than one person.

		Number of laundries per household per year	Number of automatic dish washes per household per year
Number of households in DK	2,532,000
Number of households with one person	1,094,000	150	0
Number of households with more than one person	1,438,000	400	300

It is assumed that each household of one person has 150 laundries per year and on automatic dish washes, whereas households of more than one person have 400 laundries and 300 automatic dish washes per year.

Recipes for prototypes of laundry detergents and tabs for automatic dishwashing has been set up based on information from SPT and the industry (2007). The prototypes are set up both for the builder system in phosphate-free system and phosphate-containing systems. The concentrations are average values based on more than one input.

Phosphate-free laundry detergent (builder system):

Dose 70 g/laundry

	Weight percent	g per laundry
Zeolite	25	17.5
Sodium silicate	8	5.6
Sodium carbonate	20	14
Citric acid	2.5	1.8
Sodium citrate	7	4.9
Polycarboxylates	1.0	0.7
Phosphonates	0.5	0.4

Phosphate-containing laundry detergent (builder system):

Dose 70 g/laundry

	Weight percent	g per laundry
Phosphates	20	14
Sodium silicate	3	2.1
Sodium carbonate	8	5.6
Sodium citrate	7	4.9
Polycarboxylates	4	2.8

Phosphate-free automatic dishwashing tabs:

Dose 22 g/tabs

	Weight percent	g per wash
Sodium citrate	15	3.3
Citric acid	15	3.3
Sodium silicate	15	3.3
Sodium bicarbonate	23	5.1

Phosphate-containing automatic dishwashing tabs:

Dose 22 g/tabs

	Weight percent	g per wash
Phosphates	45	9.9
Sodium carbonate	15	3.3
Sodium bicarbonate	15	3.3