8/12/2019 Role of Phosphates in Cleaners

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Milacron Marketing LLC | Cimcool Fluid Technology | Cincinnati, Ohio 45209

The Role of Phosphates in Cleaners

Milacron Marketing LLC Technical Report No. 1/08

The Role ofPhosphates in leanersWhat Are PhosphatesPhosphates are naturally occurring compounds that are acombination of mineral phosphorous, hydrogen, andoxygen. These compounds are important nutrients for

plants and animals as well as a key component in manytypes of cleaners and fertilizers. Even though phosphatesare found everywhere, too much can be a bad thing.Because phosphates are considered nutrients, highconcentrations can disturb the balance of an aquaticenvironment, causing plants, such as algae, to growrapidly. The discharge of phosphates into wastetreatment and sewage systems is regulated. As a result,some industrial facilities are placing restrictions on thecontent of phosphate in the cleaners that they use.

Phosphates in Cleaners Phosphates have been referred to as an all-purposechemical in the cleaner industry. They are usually the keyingredient in detergent formulations ranging from liquidsto free-flowing powders. When formulated into cleaning

products, phosphates are considered to be bui lders.

An important functional property of phosphates is thatthey contribute to the overall detergency of a cleaner byproviding and controlling alkalinity. Having the proper pHcan assist in removal of fatty soils, protection againstcorrosion, suspension of soils in water and prevention ofthe redeposition of soils on the surfaces being cleaned.

To make the cleaner as effective as possible throughoutthe washing process, it is essential that the pH of the bathremains stable. Since alkaline-based cleaners are able toremove soils that are on the acidic side of the pH scale,the pH of the cleaning solution may fall slightly, especiallyin industrial cleaning processes where the baths are keptfor several days or weeks. Due to their buffer capacity,phosphates neutralize this variation and maintain an

optimal pH in the bath. In addition, the alkalinity providedby the phosphate helps the cleaner attack impurities bystrengthening the action of the other ingredients.

Hard water can be an issue in many industrial cleaningapplications because it is able to cause scale that canclog pipes and other industrial equipment. Phosphatesare able to soften water by deactivating water hardnessminerals through sequestration (holding metal ions) orprecipitation (removing metal ions from solution asinsoluble materials). Sequestration of calcium andmagnesium ions to soften water is pH dependent andweakens drastically below 9.5. Phosphates counteractthe effect of dissolved iron, calcium and magnesium ionsthat are present in hard water by preventing them from

combining with other components of the formulation. Thisaction allows the cleaner to function properly. As a result,the required cleaner concentration is decreased.

Phosphates are also used to prevent calcium andmagnesium scale from forming on parts and/or washersystems. Phosphates exhibit an anti-redepositionproperty that helps to break up large particles of dirt intosmaller ones, which are easier to wash from the surfaceof the substrate. They also prevent fine dirt particles fromcombining, which helps them remain suspended insolution. This property also prevents dirt from settlingback onto parts during the washing cycle as well asemulsifies grease and oil that are found in the system.

Other important aspects of phosphates; they help in theefficient manufacture, storage, and use of detergents bystabilizing the detergents properties. Phosphates are

highly soluble compounds, therefore they also aid indissolving the cleaner into solution and are considered tobe much easier to rinse.

Why Target PhosphatesIn the 1970s, the US government recognized theproblem with phosphorous pollution. It was found thatresidues from fertilizers and cleaners were causingexcessive growth of algae in fresh water lakes andstreams. This nutritional enrichment is referred to aseutrophication. Phosphates have the ability to enter backinto the environment unchanged through sewage fromboth detergents and human waste and could causeoxygen depletion in waterways. When growth of aquaticplants is over stimulated they seasonally die and rot,using up the oxygen dissolved in the water. Fish die of

oxygen deficiency and are for a time replaced byscavengers.

As the plant growth cycle periodically repeats, theresource value of rivers and lakes decrease.

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CIMCOOLTechnical ReportMilacron Marketing LLC | Cimcool Flui d Technology | Cincinnati, Ohio 45209

The Role of Phosphates in Cleaners

Milacron Marketing LLC Technical Report No. 1/08

Bodies of water themselves become displacedbecause of the accumulation of plant life and thedepletion of fish. The lake first becomes a marsh ora swamp, then into a bog; later dry land. Thisprocess occurs naturally as lakes mature. It hasbeen estimated that the eutrophication, which hasoccurred over the past several decades because ofmans pollution would require thousands of years totake place under natural conditions.

Phosphate ReplacementsPhosphates fulfill a number of different functions;therefore it is difficult to replace them with oneingredient. Product reformulation requires theincorporation of multiple new raw materials to

replace one. No other single chemical offers all, oreven most, of the properties that phosphates do. Infact, a phosphate free cleaner is usually a differenttype of formulation all together.

Phosphate-free cleaners in general contain some orall of the following chemicals:

Zeolitesare principle builders that are artificialand insoluble compounds that are based onaluminum and silicate. They are known toincrease soil suspension as well as increasesludge volumes in sewage treatment, whichmakes disposal much more difficult. Zeolites areusually found in powdered cleaners.

Polycarboxylatesare non-biodegradable longchain petrochemicals that are used to reduce

build up of calcium and magnesium salts whichresult from poor ion removal properties ofzeolites. In addition, these raw materials havebeen found to be difficult to remove in wastetreatment. They may also accumulate in sludge.

Reinforced surfactant packages. Thesesystems can increase the biological demand inwater (BOD).

Sodium carbonateis used to maintainalkalinity. The problem with this raw material isthat it has low solubility characteristics; thereforeit has limited use in liquid cleaners.

Other chelants such as citrates, gluconates,NTA or EDTA can mobilize heavy metals. Theywork well in removing calcium and magnesium

ions as well as copper and iron, which canpotentially cause other problems in wastetreatment systems.

Phosphate-free cleaners may also containchemicals that are considered to be harmful.Elimination of phosphates from detergents alonemay be insufficient to solve the eutrophicationproblem. Phosphate alternatives absorb calciumions, but not magnesium. In addition, the rate ofabsorption is much slower for these alternatives,making them much less efficient. Their use, withoutany other change in the cleaner formulation wouldresult in generally poor detergency and a severeincrease of re-depositionConsult with your regional CIMCOOLTechnical

Service Engineer or call CIMCOOLTechnical

Service at 1-513-458-8199 for specific product

recommendations. CIMCOOLTechnical Service

Engineers recommend both phosphate containingand phosphate-free products as required for yourapplication.

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