About this Research Topic
Cyclic and linear siloxanes (silicones) belong to the organosilicon compounds. Because of their unique properties, siloxanes could be found almost in all areas of human life. The significant area of their usage is connected with the direct contact through the digestive system, respiratory tract or through the skin. This applies to medicinal products (e.g. oral preparations), medical devices (e.g. adhesive patches), medicinal materials (e.g. implants), cosmetics, food, environment.
Studies on the assessment of the influence of silicones on the human organism commenced at the same moment when they were introduced for use, that is in the 40 s of the 20 th century. Since that time the number of the volatile low molecular siloxanes, as well as middle and high molecular polymers have increased as well as the scope of their applications. For this reason the research related to evaluation of the eventual toxicity was intensified. Both the results and conclusions are not only ambiguous but sometimes even totally contradictory.
Among approximately 700 scientific reports and publications about 400 ones concern unfavorable effects of siloxanes on human and animal organism. The most important are: disadvantageous influence on immunologic system, liver, nervous system, organ of vision. Besides there are proved: genotoxicity, accumulation in liver, teratogenicity, changes in some proteins conformation, susceptibility for biodegradation, permeation of low molecular weight products through cell barriers and their penetration to different tissues and organs, migration from implants including breast implants to distant tissues.
Many reports and publications reported that siloxanes are not toxic.
It should be noted that these compounds have gained increased attention in recent years following the implementation of chemical legislation programs worldwide. Currently, the wide research programs are being conducted at the request of governments of Canada, Denmark, Sweden as well as the joint FAO /WHO Expert Committee on Food Additives. More and more reports of the monitoring the occurrence of siloxanes were presented, in particularly for the volatile low molecular cyclic and linear siloxanes. Apart from this, recent controversy over poor-quality silicone breast implants has once more brought the issue of silicone toxicity to the fore.
Therefore, this is an important to discuss the impact of different siloxanes on the health, safety and environment. In the general discussion on the safety of using siloxanes, it is very important to take into account the type of these. The reason for it is that toxicity and possibility of any danger effect on an organism depends on its structure and the size of the molecule but also its molecular weight.
In the context of the review of the literature, collected over the years 1948-2013, which touches upon the safety of use of the various siloxanes can be seen that there is a problem with the answer to the questions:
1) Whether cyclic and linear siloxanes are safe for human beings?
2) What kind of any interactions may be observed in organism after various siloxanes application?
3) What is the critical value which causes the toxic effect for adults, children and infants?
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