Phosphorus in laundry detergent
What is phosphorus?
Phosphorus is an essential nutrient for plant growth. It is also the ‘limiting nutrient’ required for the growth of blue-green algae in inland water systems, which means that too much phosphorus can cause excessive growth of algae and weeds. This can in turn lead to depletion of oxygen in water bodies and which can harm other aquatic life, such as fish.
Phosphorus is found in the Australian aquatic environment in a number of different forms: soluble phosphate, phosphorus that is bound to mineral and organic particles, and phosphorus within the bodies of aquatic organisms. Whilst algae can only use soluble phosphate to grow, these three forms of phosphate can interconvert, meaning they all have the potential to become bioavailable under the right conditions.
What’s the myth?
There is a general public perception that phosphorus is ‘bad for the environment’.
And, in particular, that phosphorus from laundry detergents is one of the leading causes of blue-green algal outbreaks in Australian inland waterways.
This is a misconception or exaggerated perception of the impact of phosphorus from laundry detergents (and some other household cleaning products) on the environment.
The issue of phosphorus in laundry detergents has been in the Australian public eye since high-profile algal blooms of the early 1990s in inland Australia. And the ‘Do Something!’ campaign to phase out phosphorus in laundry detergents revisited these 20-year-old events to push for further changes within the Australian laundry product industry.
FACT: The majority of phosphorus in Australian waterways is not from human sources
It has been assumed that the predominant phosphorus sources for Australian waters are of human origin, such as fertilisers, sewage and detergents. These are termed ‘point sources’.
However this is not the case.
The majority of phosphorus (an estimated 65-95%)[1] reaching Australian waterways comes from diffuse sources, primarily soil erosion. Other potential diffuse sources include runoff from rural and urban catchments where fertilisers are used, and runoff from urban areas that are contaminated by litter and domestic-animal faeces. Diffuse sources of these kinds are estimated to contribute 70-80% of the phosphorus load in NSW's Hawkesbury-Nepean catchment.[2]
It is also thought that extreme weather events, such as storms, lead to the major contributions of nutrients (i.e. phosphorus and nitrogen) to Australian waterways.[3]
A 1998 CSIRO Review concluded that “point sources may be significant in very particular, site-specific, cases, but in general diffuse sources are the major contributor to loads, and thus to the availability of phosphorus in water bodies for excess algal growth.”[3]
FACT: Phosphorus from household products has not been shown to have any significant impact on the environment.
In Australia, only very low levels of phosphorus from household cleaning products reach waterways. Phosphorus is generally removed from waste water by sewage treatment plants to levels that are acceptable to Australian environmental regulators.
Sydney Water reported that for discharges to inland waterways:
"Key nutrient loads (total nitrogen and total phosphorus) from the 15 inland plants complied with the plant specific EPL [Environment Protection Licence] limits." [4]
Most Australians live in coastal areas where treated wastewater is generally discharged to the ocean; for example, over 90% of Sydney Water’s treated wastewater is discharged to the ocean.[5] In this environment, phosphorus-containing ingredients have minimal environmental impact.
FACT: Overseas experiences regarding phosphorus do not reflect the Australian situation
Australia is often compared to selected overseas countries and their decisions regarding phosphorus. This is inappropriate for a number of reasons.
The USA, Canada and Europe all have major inland urban centres and large populations on the shores of lakes. This population pattern and its local impact are quite different to the predominantly coastal population of Australia. Phosphorus in the ocean environment has no adverse effect of significance.
Additionally, Australian inland waterways differ from North American and European waters. Australian waters are warmer, shallower and more turbid (i.e. high amounts of suspended particles). And it has been found that this Australian water profile can have “much higher levels of phosphorus in the water column than overseas studies indicate are necessary to initiate excessive algal growth”.[3]
FACT: Industry has taken action
The Australian laundry detergent industry has responded to calls to reduce product phosphorus levels. Through Accord Australasia, the national industry body, the Phosphorus Standard for Household Laundry Detergents was introduced and applied voluntarily across the industry and the nation since the mid-1990s. This Standard was developed with oversight of the NSW Environment Department.
This Standard sets limits for the amount of phosphorus in laundry detergents, and enables consumers to readily identify products adhering to this standard (the "P"’ label), or that do not contain added phosphorus (the "NP" label).
Recently, major retailers and manufacturers have agreed to phase out phosphorus in laundry detergents, following a high-profile media campaign by the Do Something! group.
Although there is no evidence that phosphorus from laundry detergent has any impact on the levels of phosphorus in Australian waterways, the industry is committed to responding to consumer needs.
Sources
[1] Summary Report of Third Year Data 2000-2001, National Pollution Inventory. www.aihw.gov.au/WorkArea/DownloadAsset.aspx?id=6442452962
[2] The State of NSW and Department of Environment, Climate Change and Water NSW 2010, Lower Hawkesbury-Nepean River nutrient management strategy, Department of Environment, Climate Change and Water, Sydney (citing Davis et al 1998).
[3] Donnelly, T. H., Barnes, C. J., Wasson, R. J., Murray, A. S. and Short, D. L. 1998, ‘Catchment Phosphorus Sources and Algal Blooms – An Interpretive Review’, Technical Report 18/98, CSIRO Land and Water.
[4] Sydney Water 2014, Sewage Treatment System Impact Monitoring Program, Interpretive Report (p26). https://www.sydneywater.com.au/web/groups/publicwebcontent/documents/document/zgrf/mdc4/~edisp/dd_078228.pdf
[5] Calculated from www.sydneywater.com.au/SW/water-the-environment/how-we-manage-sydney-s-water/wastewater-network/wastewater-treatment-plants/index.htm
Phosphorus is an essential nutrient for plant growth. It is also the ‘limiting nutrient’ required for the growth of blue-green algae in inland water systems, which means that too much phosphorus can cause excessive growth of algae and weeds. This can in turn lead to depletion of oxygen in water bodies and which can harm other aquatic life, such as fish.
Phosphorus is found in the Australian aquatic environment in a number of different forms: soluble phosphate, phosphorus that is bound to mineral and organic particles, and phosphorus within the bodies of aquatic organisms. Whilst algae can only use soluble phosphate to grow, these three forms of phosphate can interconvert, meaning they all have the potential to become bioavailable under the right conditions.
What’s the myth?
There is a general public perception that phosphorus is ‘bad for the environment’.
And, in particular, that phosphorus from laundry detergents is one of the leading causes of blue-green algal outbreaks in Australian inland waterways.
This is a misconception or exaggerated perception of the impact of phosphorus from laundry detergents (and some other household cleaning products) on the environment.
The issue of phosphorus in laundry detergents has been in the Australian public eye since high-profile algal blooms of the early 1990s in inland Australia. And the ‘Do Something!’ campaign to phase out phosphorus in laundry detergents revisited these 20-year-old events to push for further changes within the Australian laundry product industry.
FACT: The majority of phosphorus in Australian waterways is not from human sources
It has been assumed that the predominant phosphorus sources for Australian waters are of human origin, such as fertilisers, sewage and detergents. These are termed ‘point sources’.
However this is not the case.
The majority of phosphorus (an estimated 65-95%)[1] reaching Australian waterways comes from diffuse sources, primarily soil erosion. Other potential diffuse sources include runoff from rural and urban catchments where fertilisers are used, and runoff from urban areas that are contaminated by litter and domestic-animal faeces. Diffuse sources of these kinds are estimated to contribute 70-80% of the phosphorus load in NSW's Hawkesbury-Nepean catchment.[2]
It is also thought that extreme weather events, such as storms, lead to the major contributions of nutrients (i.e. phosphorus and nitrogen) to Australian waterways.[3]
A 1998 CSIRO Review concluded that “point sources may be significant in very particular, site-specific, cases, but in general diffuse sources are the major contributor to loads, and thus to the availability of phosphorus in water bodies for excess algal growth.”[3]
FACT: Phosphorus from household products has not been shown to have any significant impact on the environment.
In Australia, only very low levels of phosphorus from household cleaning products reach waterways. Phosphorus is generally removed from waste water by sewage treatment plants to levels that are acceptable to Australian environmental regulators.
Sydney Water reported that for discharges to inland waterways:
"Key nutrient loads (total nitrogen and total phosphorus) from the 15 inland plants complied with the plant specific EPL [Environment Protection Licence] limits." [4]
Most Australians live in coastal areas where treated wastewater is generally discharged to the ocean; for example, over 90% of Sydney Water’s treated wastewater is discharged to the ocean.[5] In this environment, phosphorus-containing ingredients have minimal environmental impact.
FACT: Overseas experiences regarding phosphorus do not reflect the Australian situation
Australia is often compared to selected overseas countries and their decisions regarding phosphorus. This is inappropriate for a number of reasons.
The USA, Canada and Europe all have major inland urban centres and large populations on the shores of lakes. This population pattern and its local impact are quite different to the predominantly coastal population of Australia. Phosphorus in the ocean environment has no adverse effect of significance.
Additionally, Australian inland waterways differ from North American and European waters. Australian waters are warmer, shallower and more turbid (i.e. high amounts of suspended particles). And it has been found that this Australian water profile can have “much higher levels of phosphorus in the water column than overseas studies indicate are necessary to initiate excessive algal growth”.[3]
FACT: Industry has taken action
The Australian laundry detergent industry has responded to calls to reduce product phosphorus levels. Through Accord Australasia, the national industry body, the Phosphorus Standard for Household Laundry Detergents was introduced and applied voluntarily across the industry and the nation since the mid-1990s. This Standard was developed with oversight of the NSW Environment Department.
This Standard sets limits for the amount of phosphorus in laundry detergents, and enables consumers to readily identify products adhering to this standard (the "P"’ label), or that do not contain added phosphorus (the "NP" label).
Recently, major retailers and manufacturers have agreed to phase out phosphorus in laundry detergents, following a high-profile media campaign by the Do Something! group.
Although there is no evidence that phosphorus from laundry detergent has any impact on the levels of phosphorus in Australian waterways, the industry is committed to responding to consumer needs.
Sources
[1] Summary Report of Third Year Data 2000-2001, National Pollution Inventory. www.aihw.gov.au/WorkArea/DownloadAsset.aspx?id=6442452962
[2] The State of NSW and Department of Environment, Climate Change and Water NSW 2010, Lower Hawkesbury-Nepean River nutrient management strategy, Department of Environment, Climate Change and Water, Sydney (citing Davis et al 1998).
[3] Donnelly, T. H., Barnes, C. J., Wasson, R. J., Murray, A. S. and Short, D. L. 1998, ‘Catchment Phosphorus Sources and Algal Blooms – An Interpretive Review’, Technical Report 18/98, CSIRO Land and Water.
[4] Sydney Water 2014, Sewage Treatment System Impact Monitoring Program, Interpretive Report (p26). https://www.sydneywater.com.au/web/groups/publicwebcontent/documents/document/zgrf/mdc4/~edisp/dd_078228.pdf
[5] Calculated from www.sydneywater.com.au/SW/water-the-environment/how-we-manage-sydney-s-water/wastewater-network/wastewater-treatment-plants/index.htm
