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Chemically resistant sealants to prevent soil contamination

SABA often receives queries from actual practice asking about what sealants are resistant to what chemical substances. Locations that make commercial use of soil contaminants must always use the right sealing system to prevent soil contamination and other negative, even disastrous, consequences. What system is suitable depends on various factors, such as legal requirements*, the application and the potential chemical load.


The right chemically resistant sealing system

A sealant's chemical resistance indicates the degree to which a joint sealant is resistant to certain chemical substances. Chemically resistant sealants are used to create a controlled environment in which soil contamination is prevented. This includes things such as floor seals for filling stations or seals in spill containment units at storage silos. A sealing system’s suitability is determined on the basis of the following factors.
 

The soil contaminant involved

To be able to select a suitable sealing system it is essential to know the soil contaminant involved. It is also important to know its concentration and the temperatures to which the chemical substance and the joint seal are exposed.

 

The applicable standards and legislation

The standards and regulations that apply to protecting the soil may differ from one country to the next. The standards that apply to sealants, such as a European CE EN 14188-2-based marking or an additional country-specific requirement such as the German Allgemeine Bauaufsichtliche Zulassung, for example, are determining factors in choosing the right sealing system.

 

Liquid-repellant or liquid-tight requirement**

It is important to know whether the seal must be liquid-repellant or liquid-tight. In case of a liquid-repellant requirement, the seal must be able to resist incidents involving leaks. A barrier must be created capable of keeping out a liquid for several hours or days until the chemical load is removed. For example in a spill containment unit. In case of a liquid-tight requirement, the sealed joint must be able to resist a load for years or decades. This is a requirement for tank seals, for example. 

 

The substrate

A durable and chemically resistant seal is also dependent on its adherence to the substrate. Because the substrate, combined with the soil contaminant, can affect the seal, it is important to know what substrate the seal is to be applied to. Next, the liquid’s effect on the seal must be tested.

In addition to the above factors, several other questions must be answered to be able to select a suitable chemically resistant sealing system. For example: What is the application? What are the potential loads? Will vehicles drive across the seal? Is the seal applied inside or outside? These questions can be answered together with a team of SABA specialists, taking you one step further along in your search for a suitable chemically resistant sealing system.



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SABA and advice on chemical resistance

Governments impose special requirements to prevent soil contamination at locations that make use of environmentally harmful substances, such as airports, filling stations, oil or manure storage tanks. These laws and regulations vary significantly by sector and country. SABA has been testing the chemical resistance of our sealants for years. Our expertise and experience enable us to provide our customers with the best custom advice available anywhere. We have developed an elaborate database that tells us which sealant and preliminary treatment must be used for a certain substrate combined with a chemical substance. In situations where a raw material has not been tested previously, a resistance test can be carried out.

Resistance Tests

The objective of a resistance test is to determine the right sealant by measuring the sealant’s resistance. During the test, seals are loaded with water or other reference liquids, whereby the chemicals are classified into groups on the basis of their chemical properties. After a predetermined number of days, the seal’s properties are checked. This includes an evaluation of the seal’s hardness, elasticity, mechanical damage, discoloring and elastic recovery, among other things. The test results indicate whether a seal is chemically resistant, and if so, for how long. SABA’s R&D department conducts these tests in-house.

Figure 1: Results of a gasoline resistance test. You can clearly see that Sabatack 750 (left) and a competitor’s polyurethane (right) absorb more of the test liquid, causing them to swell more. SABA Sealer MB (center) is significantly better suited.
 
Figure 2: Results of an acetic acid resistance test. In this test SABA Sealer MB (center) and SABA Sealer AC (right) are not affected; by contrast, a competitor’s polyurethane (left) is affected.

SABA’s chemically resistant sealants

SABA has many years of experience in sealing joints that are chemically and petrochemically resistant. Two products that we frequently recommend, among others, are SABA Ecoseal AC and SABA Sealer MB-T. These two sealing systems are resistant to extreme weather conditions and provide a durable, elastic, chemical and petrochemical seal.

SABA Ecoseal AC

SABA Ecoseal AC is highly suitable for biochemical loads, such as tanks, silos, storage basins and storage areas that come into contact with composting processes, manure and treated water. This acid-resistant sealant is permanently elastic, free of hazard labels and easy to process.

SABA Sealer MB-T

SABA Sealer MB-T is highly suitable for installations in the petrochemical industry where harmful substances are stored and/or topped up. This durable, elastic sealant does not contain any solvents, is resistant to extreme weather conditions and has a 25-year reference period.

* The reader must always inform him/herself of the latest laws and regulations.