WAC / PAC

WAC - PAC (polyaluminium chloride hydroxide sulfate or aluminum polyhydroxychlorosulfate).
Synonyms : Polyaluminium chloride, Aluminium chloride basic, Aluminium hydroxychloride, Aluminium chlorhydroxide, Aluminium chlorohydrol.

The aluminum enables the synthesis of polymerized species which are components of the basic aluminum polychlorides (PCBA) and aluminum polyhydroxychlorosulfate (polyaluminium chloride hydroxide sulfate, WAC, AQUALENC ...).
These products, and effective reagents, are characterized by their content of active substance in% of alumina (Al₂O₃) and basicity (B = OH/3Al%) which is also an indicator of the state of polymerization of the product.
They are used in drinking water treatment to precipitate colloids and suspended solids: coagulation / flocculation; and are used in primary sewage treatment, and in the process of chemical phosphorus removal or not combined with a biological phosphorus removal.

See Coagulation/flocculation", and reminders about the nature of the colloidal particles and the stability of their dispersions.

Polyaluminium chloride basic is a group of specific aluminium salts having the general formula : Al_n (OH)_m Cl_3n-m, (wherein [3n-m] is between 0.45 and 0.60).
_{It required to obtain the same results as other chemicals (alum, ferric chloride) usually costs about three times more expensive. However, in the case of treating turbid water, its cost will be similar to other coagulants.}

General formula aluminum polyhydroxychlorosulfate (PAC) : Al (OH)_x Cl_y(SO₄)_z
The PAC is in the form of a liquid with a content of Al₂0₃ is about 10%.

Other polychlorinated aluminum:

• Reactive about with 17% Al₂O₃ (d = 1.36): 18 PAX (basicity = 42 ± 2%), Aquarhone 18.
• Reactive with16.4% Al₂O₃ (d = 1.34): Fennofloc.

Chemical elements.
Like other coagulation reagents, the chemical action of these reagents leads:

• a decrease in the alkalinity (TAC)
• an increase in free CO2
• adding water Cl^- chloride and sulfate SO₄ (for PAC)

However, they have less impact on the pH and alkalinity and lower residue levels for example ferric chloride.
The pH range for use is from 6 to 7.5 (optimum 6.5).

Standardization.
Products must meet specific requirements to aluminum salts for food contact ( French regulations BFR XXXVI and FDA).
Standard products used for the production of drinking water: Official French Bulletin - NF EN 883 type 1 (products use in treatment of drinking water treatment).
Links : Circulaire DG 5/VS 4 n° 2000-166 28 mach 2000, on the products of the methods of treating water intended for human consumption.

Uses others
In the papermaking industry, they are used as retention agent for the formation of sheets, or as a coagulating agent on the "broke" treatment.
Aluminium chlorohydrate is one of the most common active ingredients in commercial antiperspirants. The variation most commonly used in deodorants and antiperspirants is Al₂Cl(OH)₅.
Safety.
The Food and Drug Administration (USA) considers the use of aluminium chlorohydrate in antiperspirants to be safe and it is permitted in concentrations up to 25%.

Alzheimer's disease:
There have been studies that have found an association between exposure to and long-term use of antiperspirants and Alzheimer's disease, however the studies also have shown that the association is negligible (less than 1%).[6] There is no adequate evidence that exposure to aluminium in antiperspirants leads to progressive dementia and Alzheimer's disease.

Breast cancer:
The International Journal of Fertility and Women's Medicine found no evidence that certain chemicals used in underarm cosmetics increase the risk of breast cancer. Ted S. Gansler, MD, MBA, the director of medical content for the American Cancer Society, stated "There is no convincing evidence that antiperspirant or deodorant use increases cancer risk".

The European Journal of Cancer Prevention stated "underarm shaving with antiperspirant/deodorant use may play a role in breast cancer. "The journal Breast Cancer Research proposed a link between breast cancer and the application of cosmetic chemicals in the underarm, including aluminium, with oestrogenic and/or genotoxic properties. Personal care products are potential contributors to the body burden in aluminium and newer evidence has shown that more aluminium is deposited in the outer regions than the inner regions of the breast. But whether differences in the distribution of aluminium are related to higher incidence of tumours in the outer upper region of the breast remains unknown.

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