In today’s article we intend to emphasize one of the most popular components for the production of plastics and in particular PVC. This is the DEPH, which has many advantages from the point of view ofprocessing, but unfortunately also rather serious contraindications, which we will see in more detail below.

DEHP is a phthalate, i.e. a low-volatile, generally odourless and colourless liquid substance which is mainly used as a plasticiser within thematerial for distillation, especially in everyday polyvinyl chloride (PVC) articles.

DEHP is the most widely used phthalate for PVC medical devices, because the plasticity it generates, makes the products easier to use and less likely to cause tissue damage. The DEHP content in polymeric material varies around 30-35%, while in medical devices it can be present from 20 to 40% of the total weight.

This substance is added by incorporating into the polymer chains, causing a distance between them and, consequently, making the material flexible, soft and easy to work; while non-plasticized PVC is hard and brittle at room temperature.

For the above reasons, it is used in various fields, including medical, for example, for: the production of intravenous tubes, blood bags and infusion tubes, nasogastric tubes, hemodialysis tubes, etc …

As for the blood bags, the compound also acts as a stabilizer and ensures longer storage times.

Some substances do not chemically bind to the polymer, and the consequence could generate a release of DEHP from plastic medical devices inside the solutions that come into contact with it. The process is based on numerous factors, such as temperature, content and, above all, the duration of contact with plastic. In summary, the longer the duration of contact, the greater the risk to which the patient is exposed, with particular regard to subjects suffering from serious diseases, subjected to repeated infusions.

Many phthalates have also been identified as chemicals interfering with endocrine androgenic actions in mammals. This conclusion has been deduced following several studies, for example, a large one on rats, which have shown how DEHP can compromise testicular function, a fact confirmed by further recent research, which, more specifically, underline an energetic inhibitory effect on testosterone production in adult men.

The conclusions, not very reassuring, of the above works, converge on the hypothesis that these substances can therefore significantly modify the hormonal quotas with potential reverberations on the development of the reproductive systems, nervous and systemic metabolism, also determining a predisposition towards oncological evolutions.

From the above, it is easy to understand how, for some time, the DEPH has been the subject of discussion and subjected to numerous scientific researches all over the world, and now the consolidated recommendation is oriented to limit its use, in particular to avoid exposure especially on newborns with serious diseases, such as to make them subject to various clinical procedures, For which, of course, the insult was amplified compared to adults, due to their reduced body weight.

Regardless of the above evidence, other research conducted on guinea pigs has led to the discovery of an incontrovertible relationship between DEHP and the incidence of neoplasms affecting the liver, lungs, heart and kidneys, as well as considerable repercussions on fetal development, on the induction of peritoneal sclerosis, and various other diseases.

Many steps have already been taken by the European Union towards a gradual abandonment of use, including the classification of DEHP and three other substances (DBP, BBP, DIBP) as toxic and, since 7 July 2020, through Regulation 2018/2005 / EU, the Community has established a ban on the placing on the continental market of these phthalates, in toys and in articles with a concentration equal to or greater than 0.1% by weight of the plasticized material.

The completion of this path, under the EU regulation on medical devices, will take place after 26 May 2024, when the application of DEHP in production processes will require a solid technical-scientific justification, consistent with the latest guidelines of the relevant scientific committee. According to the EU chemicals regulation REACH, in fact, the use of DEHP in the remaining applications must be stopped by 14 December 2024 and in medical devices by 27 May 2025.

To date, there are already several alternative flatates to be used in the production of PVC, and materials are being developed that can be considered, to all intents and purposes, substitutes for DEHP; However, it is necessary to fully understand not only the leaching properties but also the potential toxicity and their overall impact on the effectiveness of the treatment.

An apparently valid potential alternative, which is still the subject of numerous studies, is the DEHT; a plasticizer for general use, completely hydrolyzed, which has the same number of atoms as DEHP, but different structural formulas and physical and chemical properties, which exclude it from the class of phthalates.

Right now, and until proven otherwise, it is becoming the main replacement, tested on many applications and with a complete toxicology portfolio; which allows the use in the production of toys, packaging and medical devices. In addition, it complies with the requirements imposed by the European Union relating to the use of substances in toys and products in contact with food.

In conclusion, the research monitors and correctly focuses the priority on public health. The convergence of evidence is leading to a virtuous evolution of production protocols for plastics, focusing on substances with less and less toxicity, especially when it comes to using them in the medical field. Obviously, this evolution passes through the revision of industrial processes on the one hand, and the structuring of a restrictive and congruous regulatory framework on the other.