Chlorine (Chlorate) in Dietary Supplements

Ein Bericht aus unserem Laboralltag

Bauer-Aymanns, Dr. Lerch, Dr. I. Ruge

 

In 2014 and 2015 CVUAs Karlsruhe and Stuttgart investigated several samples of liquid dietary supplements, one coming from the USA, that were not only contaminated with trihalogen methanes, but also contained high levels of chlorine, chlorate and perchlorate. According to the ingredients list, however, the products should have only contained water and sodium chloride (common salt). The samples were judged as inacceptable for human consumption.

 

Meanwhile, in an official opinion, the Federal Institute for Risk Assessment (BfR) categorized this product as being harmful to one’s health, due to its high quantities of chlorate and perchlorate [3]. Furthermore, the health claims of “redox effects” were deemed extremely deceptive. The designation „dietary supplement“ is also not legitimate.

 

Miraculous Effect of „Reactive Oxygen Species” (ROS)

The product is filled in liter-sized bottles and sold via the Internet. Advertisements claim it consists of “billions of perfectly balanced redox-signal molecules that float in a pure salt solution.” It is also alleged that the „ROS“ molecules can increase athletic performance, as well as strengthen resistance to illness and early aging. Moreover, it is supposedly “one of the safest products on the planet”. However, there is no serious scientific evidence for these claims of efficacy.

 

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„Reactive Oxygen Species“ (“ROS“)

„Reactive oxygen species are often vaguely referred to „oxygen radicals“ or „free radicals“. The Internet advertisement for this analyzed product depicts the effectiveness of these molecules as positive!


On the contrary, ROS molecules are formed via normal cellular reactions in oxygen metalizing organisms (humans and animals) and, due to their oxidative effects, are damaging to cells. More information can be found in Wikipedia under http://en.wikipedia.org/wiki/Reactive_oxygen_species.

 

Based on this understanding, the trend toward using anti-oxidative substances in dietary supplements has spread widely in recent years because it is seen as physiologically advantageous for protecting cells from oxidative stress.

 

Quantities of Chlorine and Trihalogen Methanes (THM)

During the initial, sensory analysis there was an unpleasant smell and taste of chlorine. The pH value was close to neutral. The chemical analysis showed free chlorine in quantities of up to 16 mg chlorine/l; however, after water is treated with chlorine only a maximum of 0.3 mg of free chlorine/l is permitted.
Furthermore, the chlorine reacted with organic contaminants in the water, forming trihalogen methanes (THM), mainly chloroform, as a result. With values of up to 424 µg THM/l, the samples exceeded the value of 50 µg THM/l for drinking water many times over.

 

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Chlorine

Elementary chlorine (Cl2) is used for purification and disinfection in several ways, in order to remove the danger of germs. It is an extremely reactive compound – its toxicity is based on the destructive, strongly oxidizing effect on organic tissue.

 

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Trihalogen Methane (THM)

Chlorine reacts with organic elements that exist naturally in water and cause unwanted by-products; it is used, e.g. for the disinfection of drinking water or the treatment of water in swimming pools. In terms of health safety, the trihalogen methanes (THM) are of concern because they are suspected of being potential cancer-causing agents. Their quantities are thus regulated and monitored.

 

Unusual manufacturing processes for food

The product is probably made into a salt water solution via electrolysis (see diagram). A strong chlorinated salt solution contaminated by THM thereby remains in the anode chamber. The chlorine content is kept secret from the consumer, although the Internet advertisements for the „redox effects“ of „ROS molecules“ must state the presence of chlorine and its reaction products.

 

Illustration: Membrane chloralkali process. Author: Jkwchui. This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.

Illustration: Membrane chloralkali process. Author: Jkwchui. This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. Source: https://en.wikipedia.org/wiki/Chloralkali_process.

 

Quantities of Chlorate and Perchlorate

The investigation into further chlorine compounds revealed high levels of strongly oxidative chlorate as well as perchlorate (19.5 mg/l and 0.36 mg/l).

 

Contamination of plant-based foods with chlorate and perchlorate has been an important issue for food control for several years. CVUA Stuttgart has already published several Internet reports on this issue, including:

 

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Chlorate

Chemical structure chlorate.

Chlorates are the salts of chloric acid. They are strong oxidative substances that are used, e.g. in the bleaching of paper. The disinfection of drinking/utility water with chlorine produces chlorate as a by-product, as does the use of a chlorine bleaching agent (sodium hypochlorite solution). Chlorate can also exist as a result of the use of chlorine dioxide for the disinfection of drinking/utility water.

 

Perchlorate

Chemical structure perchlorate.

Perchlorates are the salts of perchloric acid. They are mostly soluble in water and are persistent throughout the environment. They exist in the environment not only as a result of anthropogenic (human) activities, but also exist in natural mineral deposits. The intake of perchlorate can lead to a reversible inhibition of iodine absorption by the thyroid.

 

Legal background and toxicological evaluation of chlorate and perchlorate

Chlorate

No specific maximum residue levels (MRL) have been established for chlorate in food or drinking water thus far. The Federal Institute for Risk Assessment (BfR) only recommends use of the World Health Organization’s acceptable daily intake (ADI) derived for chlorate in food such as fruit and vegetables: 0.01 mg/kg body weight. This is to be used as a provisional basis, for chronic as well as acute risk assessment (acute reference dose (ARfD)) [1]. The European Food Safety Authority (EFSA) published a risk assessment for chlorate in food on 24 June, 2015, specifying a tolerable daily dose (TDI is similar to ADI) of just 0.003 mg/kg body weight and an ARfD of 0.036 mg/kg body weight. [4]
The label on the analyzed product recommended a daily consumption of 118 ml. Calculating the intake for a 70 kg adult as an example, the ADI of 0.01 mg/kg body weight for chlorate would be exceeded threefold. The TDI of 0.003 mg/kg body weight established by EFSA would be exceeded eleven fold with this consumption amount.
Given the downplaying of any danger in the Internet advertisement, it can be realistically assumed that larger amounts will also be drunk.

 

Perchlorate

Perchlorates are not authorized in the EU as a food additive. There is no legal maximum amount established for food yet. [2] Therefore, perchlorate findings fall under the guidelines in contaminant regulations, which serve to protect consumers via a general minimization imperative for foreign substances in food. Given perchlorate‘s higher toxicity compared with that of chlorate, EFSA established an even lower TDI value of just 0.0003 mg/kg body weight. Since perchlorate residues found in the product were lower than chlorate residues, a daily intake of 119 ml would mean a twofold exceedance of the TDI for perchlorate.
The BfR comes to the conclusion, therefore, that „in consideration of the normal conditions under which the consumer uses the product, a significant, chronic exceedance of the ADI (or TDI) derived for chlorate as well as perchlorate can be expected. The health-based ADI or TDI values give the tolerable, daily amount of a specific substance that a person can take orally, lifelong, without expecting any detrimental effects. The long-term exceedance of these values would not be seen as tolerable from a toxicological viewpoint.”

 

Literature

  1. [1] BfR-Stellungnahme  Nr. 028/2014 „Vorschläge des BfR zur gesundheitlichen Bewertung von Chloratrückständen in Lebensmitteln“ vom 12.05.2014.
  2. [2] Empfehlung des BfR zur gesundheitlichen Bewertung von Perchlorat-Rück­ständen in Lebensmitteln, Stellungnahme Nr. 015/2013 des BfR vom 06. Juni 2013
  3. [3] Gesundheitliche Bewertung eines Nahrungsergänzungsmittels durch das BfR vom 30.4.2015, Nr. 8325729
    [4] Risks for public health related to the presence of chlorate in food, EFSA Panel on Contaminants in the Food Chain (CONTAM), EFSA Journal 2015;13(6):4153

 

Artikel erstmals erschienen am 10.09.2015