Until a few years ago, asbestos was used in the construction industry for the creation of partitions, roofs, coverings and systems. However, due to its very nature, it has caused several problems for health and the environment, such as to require over time numerous and repeated remediation processes.
L’asbestos encapsulation It is one of the techniques of quenching and tempering and consists in treating the materials with coating or penetrating products capable of forming a protective film on the surface. This is a complicated procedure, to be implemented in compliance with the relevant regulations and with all the attention required by the case.
But what is it, how does it work, what are the relevant regulations and what are the pros and cons of asbestos encapsulation?
Below you will find all the explanations to these questions.
Advertisement – Advertising
Asbestos encapsulation: what is it?
Asbestos encapsulation is a remediation procedure used to safely manage asbestos present in buildings or within some structures, without proceeding with removal and disposal operations.
In other words, encapsulation is an intervention to maintain the original covering, possible thanks to the application of covering products that allow to seal in an appropriate and safe way the asbestos fibers. With this treatment, the asbestos fibers are fixed and sealed while the original covering is preserved for several more years.
Compared to removal and confinement remediation processes, asbestos encapsulation is more cost effective and quicker to implement.
On the other hand, however, unlike removal, the risks of exposure to asbestos are not completely eliminated because over the years the covering liquid used loses its capacity, with the concrete risk of further dispersion of asbestos fibres.
The reason why the current regulations, in case of asbestos encapsulation, require periodic checks and constant maintenance interventions. So it is a remediation procedure with pros and cons, positive and negative aspects that we will analyze in detail later.
Advertisement – Advertising
The stages of the asbestos encapsulation procedure
Remediation through asbestos encapsulation is a complex procedure that can be carried out in various phases:
- the first phase concerns the preliminary inspection for the evaluation of the materials containing asbestos;
- the inspection is followed by an initial treatment to understand the real feasibility of the encapsulation. In fact, complications could arise that would discourage its feasibility. If positive, the process is continued with a spray treatment using an isomeric formulated primer to seal the asbestos fibers well and to form a solid base for subsequent treatments;
- the next phase instead involves the application of a fixing primer with water-based resins;
- we then continue by applying a consolidating primer, always water-based to better safeguard the environment. The types of products used penetrate the asbestos sheets, strengthening the cement matrix containing the fibres;
- the procedure is completed with the application of a liquid waterproofing sheath.
But how long does asbestos encapsulation last?
The duration of a similar procedure depends greatly on the products used and is also influenced by external factors: generally, with the use of standard products, the duration is about twenty yearswhile when the interventions are carried out with high-performance products the duration of the asbestos encapsulation can reach up to thirty years.
In any case, over the years it is essential to intervene with periodic checks and constant maintenance activities to be foreseen with the specific intervention plan.
Advertisement – Advertising
The reference legislation
Asbestos encapsulation is a serious and complex remediation procedure, therefore it is regulated by specific laws. In our country, the main reference standards can be traced back to the Ministerial Decrees of 6 September 1994 and 20 August 1999.
The first DM provides the methods for the analysis of asbestos fiber dispersions, exposure limits and indicates the processes for the encapsulation of materials, removal and confinement. The Ministerial Decree of September 6, 1994 also establishes guidelines to facilitate the choice of the type of remediation to be carried out and the implementation of verification and maintenance plans.
Instead, the Ministerial Decree of 20 August 1999 provides for the study of specific techniques, with the definition of the materials used for the encapsulation of asbestos.
In order to obtain the certificate of conformity, the supplier of the products, in accordance with the current legislation, has the task of presenting to the reference laboratory the samples of the encapsulation products with the useful information for the correct application: type of thinner, drying times, thickness to be applied, etc. In the certification of conformity, the laboratory must report at least the most important information:
- the reference specification;
- the information to identify the encapsulating cycle analyzed;
- the types of specimens used;
- the results relating to the measurement of the thickness of each product used and the overall coating thickness;
- the final assessment on the conformity of the coating and the date of the tests carried out.
Instead, it will be the responsibility of the person responsible for the remediation company’s interventions to certify the execution of the works. This latter certificate is also useful to allow the client to be able to correctly plan the control and maintenance schedule to be presented, upon request, to the competent control body.
It is therefore the client’s duty to correctly store the certificate of execution of the works issued by the person responsible for the interventions of the remediation company.
Advertisement – Advertising
Control and maintenance activities
To ensure the stability of the asbestos encapsulation, it is necessary to provide a plan for periodic checks and maintenance. The responsibility for the execution of this plan lies with the client who must act through:
- checking the encapsulating coating for any detachments or flaking from the affected surface;
- checking the color of the last layer to verify its condition.
If necessary, it will be essential to intervene as soon as possible to restore the conditions of the encapsulating coating and to apply an additional layer of product to compensate for the one that has disappeared due to atmospheric effects.
Furthermore, companies that carry out maintenance work on structures that do not involve the removal of asbestos but may release asbestos fibres have the duty to send a specific notification to the competent supervisory body, within thirty days of the start of the work, in which the associated risks are reported.
This notification must include information regarding the location of the construction site, the types and quantities of asbestos handled, the number of workers, the activities involved, the safety measures implemented and the start date and duration of the related works.
Advertisement – Advertising
Asbestos Encapsulation: Pros and Cons of the Remediation Procedure
Asbestos encapsulation is a remediation process with advantages and disadvantages, pros and cons to be analyzed with extreme interest.
Between Main advantages These include the reduced costs compared to removal and confinement operations, the lower environmental impact because the asbestos is not removed but left in place, the lower risk of exposure to asbestos for the workers involved and the absence of dangerous waste to dispose of.
However, this procedure does not only present the indisputable advantages just described, on the other hand with the encapsulation of asbestos there are also some downsides.
First of all, this remediation procedure does not have permanent effects, as the asbestos remains inside the structures and future work to permanently remove it is not excluded. Furthermore, with the encapsulation of asbestos it is necessary to implement a constant control and maintenance plan.
Advertisement – Advertising
Asbestos Encapsulation: Conclusion
In the field of remediation of sites contaminated by asbestos fibres, there are three types of techniques regulated by law, from which to choose depending on the conditions of the structures containing asbestos.
The three types of remediation recognized and regulated by law are
- asbestos encapsulation,
- removal
- the confinement,
They are different types of remediation, each of which is adaptable to specific cases and with its own pros and cons. In this article, the asbestos encapsulation procedure has been discussed, certainly cheaper than the other two but also with less positive aspects.
Asbestos encapsulation is usually used in the case of compact matrices of asbestos and asbestos cement materials, provided that the materials are still in a fairly acceptable state. In the case of excessively deteriorated materials, however, it is not possible to carry out the treatment. The encapsulation technique is particularly suitable for the treatment of materials with a reduced thickness.
Only specialized companies must be entrusted with the encapsulation of asbestos, as required by the Ministerial Decree of 20 August 1999. This is because treating asbestos is not child’s play, there are many risks and workers must be put in a position to operate in complete safety. The legislation is clear: nothing must be left to chance and all the required constraints must be respected. Legislative Decree 81/08 (Consolidated Law on Safety) protects workers’ health and safety in the workplace, providing for heavy sanctions for offenders.
Therefore, all parties involved in asbestos encapsulation operations must strictly comply with the relevant regulations, in order not to be heavily sanctioned and above all to not seriously jeopardize the health of workers involved in the remediation operations.
