Statement of the expert opinion of the FRESENIUS INSTITUTE, Chemical and Biological Laboratories, limited liability company. Taunusstein, dated 10. April 1985, about the detrimental effects of RIWO – SAN TR - 50 disinfectants.

Ref.: Detrimental Effects of Disinfectant RIWO – SAN

RIWO – SAN, the disinfectant produced and distributed by you, for water sterilization, is a colorless, watery liquid with the main component hydrogen peroxide ( H 0 ). The examination of the product sample we had at disposal showed a hydrogen peroxide content of 47 quantity – % .

In this concentration hydrogen peroxide proves to be very caustic and affects especially the skin while developing white, pungent spots. Therefore the commercially approved concentrate RIWO – SAN must be treated with corresponding precautions (gloves goggles, protective clothing) . (This is also in accordance with handling other concentrated chemicals like chlorine bleaching caustic soda). Hydrogen peroxide entirely dissolves in water and is diluent with water in any ratio. In thinner dilution hydrogen peroxide loses its caustic effect As a concentration below 3 % it is used as a medicinal disinfectant, especially as a mouth-disinfectant. This concentration of H 0 accords to a diluted RIWO – SAN solution of 1:16. (With this kind of application we recommend to suggest a solution of 1: 20).

For water disinfection a much smaller quantity of hydrogen peroxide is needed. The new drinking-water treatment regulation in Germany presently in planning, allows for drinking-water disinfection an additional limited 17 ml / l H202, which corresponds to 36 ml / l RIWO – SAN. Quantitatively this amounts to 36 ml / l RIWO – SAN for 1 cbm water or 1 ml RIWO – SAN for 30 liter water. In this concentration RIWO – SAN is totally harmless to the health and has no toxic effects on either the skin or the mucous membrane of the mouth or the gastric area. Hereby is to be noticed that the actual application concentration in real practice will lie under the maximum value, usually about 10 – 20 ml / l. (According to the revision of the drinking-water, regulation drinking-water, supplied to the customer, may contain a residual H202 concentrate of 5 mg / I, which amounts to about 10 mg / l RIWO – SAN. The additive must consequently be served under consideration of the final concentration for the own use of water).

Damage to fish or lakes and rivers with fish is not to be expected when using 36 mg / l RIWO – SAN. According to the bibliographical data, the toxic concentration for fish lies at 40 mg / l with H2O2 (corresponds to 85 mg. / l RIWO – SAN) and the interference factor for fish nourishing animals lies at 2.500 mg / l with H2O2. ( corresponds to 5,3 g / l RIWO – SAN).

According to our analysis RIWO – SAN contains 850 mg / l silver, presenting another toxicological relevant component. This complies with the following quantity of silver in drinking-water when applying RIWO SAN for the drinking-water disinfection:

The present drinking-water treatment regulation and also the planning of the new regulation allow an additive of 100 ug / l silver to the drinking-water, so that the silver additive during the watertreatment will lie consideralbe under the authorized amount.

Therefore the silver content in RIWO - SAN is toxicologically seen insignificant.

Composing an entirety RIWO - SAN contains phosphate in quantities of 0.12 mg /l Po4 (corresponds to 0.09 mg / l P2O5). These amounts are physiologically and toxocologically unimportant, especially when diluting in small doses as during the application of RIWO - SAN for the drinking-water disinfection.

Natural ground water usually contains 0.1 to 0.3 mg / l phosphate (PO4) and the drinking-water regulation allows a phosphate additve up to 6.7 mg / l (corresponding to 5 mg / l P2O5) to the drinking-water. Comparing these numbers shows that the phosphate additive of RIWO - SAN during drinking-water treatment is enormously low.

Summary:

The aforesaid comment show that RIWO - SAN has no toxic properties because of hydrogen peroxide or its content of silver or phosphate when applying for drinking-water disinfection in the prescribed dosage. The hydrogen peroxide and silver concentration correspond to the requirements of the drinking-water regulation when applied correctly, so that there appears no harm to health during a constant consumption of drinking-water treated with RIWO-SAN. Detrimental changes in water compounds through hydrogen peroxide or silver are not known to this date. Hydrogen peroxide itself decomposes into chemically clear water and oxygen without leaving toxic or harmful residues to the environment.

10th of April 1985