Since the Weekly Quality Podcast exposed the excessive chromium content in the capsules used by some pharmaceutical companies, the China Food and Drug Administration has issued an emergency notice requesting the suspension of the sale and use of 13 pharmaceutical hollow capsule products.

The reason why chromium exceeds the standard in capsules occurs is that the black-hearted enterprises use industrial gelatine instead of medicinal gelatine when making capsules. Qualified pharmaceutical gelatin used in pigskin and cowhide should be without chromium salt tanning or not contaminated with harmful metals tannery raw or fresh skin, frozen skin. And tannery trimmings can only be used to produce industrial gelatine.

So why is chromium used in leather treatment? How dangerous is chromium to human health?

Trivalent chromium and hexavalent chromium are different

From animal skin to leather, it goes through roughly four stages of treatment. The first is pre-treatment, which removes the flesh and preserves it; then comes the preparation stage, which degreases and dehairs it; next comes tanning, and finally finishing. One of the tanning stages allows the leather to become soft and durable. The process of tanning is a series of chemical reactions between high value cations and collagen. Since 1893 the American Martin-After the invention of chrome tanning by Martin Dennis, about 90% of the world's leather is tanned by this method. This is why leather contains a lot of chromium.

There are two main forms of chromium in nature, a trivalent chromium, which is the chromium used for tanning, is a cation with three positive charges. The ionic charge is the key to the tanning that can occur, and in addition to trivalent chromium, the common trivalent cations that we live with, such as trivalent iron, aluminum, and some less common ones like zirconium and titanium, are all used for tanning. It's just that chrome tanning is a mature and cost-effective process that still rules the leather and its products industry today.

Another form of chromium is the infamous hexavalent chromium, which holds together with oxygen atoms to form an atomic group in the form of chromate. Hexavalent chromium is highly biotoxic and carcinogenic with long-term exposure, with acute toxic doses ranging from 50-150 µg/kg. Even in the leather industry, hexavalent chromium is an obnoxious chemical. All countries have clear requirements on the content of hexavalent chromium in leather, the most stringent is Germany, in 2010 Germany's newly revised decree stipulates that there shall be no hexavalent chromium detection in leather.

There are rumors on the Internet that ingesting 14 ppm (parts per million) of chromium can cause genetic mutations [Note], which is a misinterpretation of the literature. Changes in gene expression levels as described in the literature are not the same as mutations (to use a poor analogy, a change in gene expression level is a change from a child to an adult, whereas a mutation is a change from a man to a woman, which is a far cry from a mutation in the human body). Also, the rumor confuses total chromium with hexavalent chromium. In short, eating capsules with chromium overload does not cause harm to the body in the form of genetic mutations as rumored.

Difficult to assess the hazards of industrial gelatin

Trivalent chromium is much less toxic than hexavalent chromium and has certain physiological functions, so trivalent chromium once existed as an additive to health care products in Western countries - although the number of people in the world who have become ill due to a lack of chromium is less than the number of people who claim to have seen aliens, and there is no need for chromium supplements. However, taking advantage of this, in 1999, a patent was filed in China for high-chromium gelatine (characterized by the presence of trivalent chromium, with a chromium content of more than 2 mg/kg), in which it was clearly stated that high-chromium gelatine could be prepared from the chrome leather trimmings of the tannery industry and could be used as an additive to food and pharmaceuticals. The patent also indicates possible applications for high-chromium gelatine, including: jelly, marshmallows, milk sugar, gelatine, lollies, ice-cream, yogurt, ham sausages, pharmaceutical pills, pharmaceutical capsules, alcohol and soy sauce.

However, this patent is obviously not available in the food and pharmaceutical industry, because the current national technical standard for edible gelatin (GB6783-94) clearly states that the chromium content should not exceed 2 mg/kg.

Accurately assess the health risk of industrial gelatin is more difficult, there are two reasons, first, tanning although the use of trivalent chromium, but industrial tanning reagent is not pure, inevitably contains hexavalent chromium, trivalent chromium and hexavalent chromium is coexisting in the leather; Secondly, the toxicity of the less trivalent chromium and toxicity of the intense hexavalent chromium can be converted to each other in the use and preservation. Northeast Agricultural University researchers in the laboratory to simulate the extraction of leather gelatin, the results found that the total chromium content of more than 25 times, hexavalent chromium content exceeds the standard more than 100 times.

In 2010, the results of a market survey conducted by researchers from Hebei University showed that 13 out of 15 food samples with added gelatine exceeded the standard of 2 mg/kg, and 10 of them exceeded 100 mg/kg. There is no doubt that industrial gelatine was added to these marketed food samples.

The problem of industrial gelatin is not only in chromium exceeding the standard. In the previously mentioned leather treatment process, PCP may be used for preservation, sodium sulfide for preparation, azo dyes for the dyeing process, and formaldehyde for the polishing process ...... So, in any case, industrial gelatine should not be used in food and medicine.

Finally, it must be pointed out that it is the responsibility of the national regulatory authorities to ensure food safety and drug safety for the people. Since China has already included chromium in the 2010 edition of the Chinese Pharmacopoeia, it should strictly regulate and nip the danger at the bud, rather than mending the fold only after each incident.

                               (Source: Nutshell.com)