What is activated alumina?

Activated alumina is used in most effective water filtration systems. Activated alumina is made from alumina, or aluminium oxide, which is abundant in the natural environment in the form of minerals. It combines with other substances without changing its chemistry or form. It is therefore a stable, non-toxic compound that does not produce any harmful by-products or waste.

Why is it used?

Activated alumina is used for water purification in industrial applications, municipal facilities and domestic water filtration systems. It is a highly effective process for removing fluoride, lead, arsenic and other contaminants.

How does it work?

Activated alumina is highly adsorbent. Because it is porous, its surface area is much larger than its weight, ensuring that large quantities of substances are trapped. Water passes through the filter and contaminants ‘stick’ to the surface of the activated alumina particles, binding to the solid material and becoming permanently trapped. Adsorption is both electrostatic and physical. In the first case, as alumina is positively charged, it will adsorb negatively charged ions. In the second case, the molecules are adsorbed by van der Waals forces.

Aluminium and health risks

Aluminium, like all heavy metals, is toxic if absorbed in large quantities.

Studies have been conducted and links have been found between aluminium absorption and various diseases, although some of these links have not been formally proven. This is the case, for example, with Alzheimer's disease, for which there is currently no proven cause-and-effect relationship.

The French Regional Health Agency writes: ‘Based on current knowledge, no causal link between exposure to aluminium via tap water and Alzheimer's disease can be considered.’

France Alzheimer also writes: "Furthermore, researchers have not identified any convincing biological hypothesis linking aluminium and the development of Alzheimer's disease. Thus, the HCSP report concludes that “to date, it is still not reasonable to consider that aluminium plays a causal role in Alzheimer's disease.” ( https://www.francealzheimer.org/)

Standards

The WHO has set a threshold of 200 µg/L. This limit is not based on health criteria, but rather on the appearance and turbidity of the water.

What about our Ultimate Star Filter® filters?

The nanofiltration membrane integrated into our filters is treated with activated alumina, like many filters from leading brands. This membrane is also used worldwide by many customers and in many water filtration models. In addition, it is NSF® certified and has passed REACH and RoHS tests. Nevertheless, in the interests of transparency and because we want to be sure of everything we do at Star Water Filter®, we have carried out aluminium analyses.

At 30 litres, i.e. approximately after the first 3 filtrations have been discarded, as recommended in our user guide, the aluminium level in the water is already well below the WHO recommendations, at 0.0476 mg/L, and decreases significantly with continued use of the filter.

• After 100 litres, the concentration is 0.0186 mg/L
• After 200 litres, the concentration is 0.0106 mg/L
• After 300 litres, the concentration is 0.0042 mg/L

You can find the analyses carried out by the SGS laboratory at this link.

At no time does the aluminium ion concentration approach or exceed regulatory limits. There is therefore no danger in using our Ultimate Star Filter® filters. In addition, our filter has successfully passed the REACH analyses, so it complies with European regulations and does not contain any hazardous substances.