Austenitic stainless steel surfaces can be made highly resistant to corrosion if it is properly cleaned and passivated prior to use. BioPas has
been found to be much more effective than the traditional toxic mineral acids such as nitric acid. In addition, BioPas does not pose the
environmental hazards that are present with nitric and other mineral acids.
With austenitic stainless steel, such as the 300 series, once a corrosion site has started it only gets worse, being continuous and self-catalyzing. In corrosive
environments the growth of the corrosion site will accelerate rapidly! Thus, proper cleaning and passivation of surfaces prior to use is essential to achieve maximum
resistance to corrosion.
Safe, economical cleaning and passivation lines can be set up easily with BioPas pacifying solution because of the low hazard and environmentally
safe chemicals. Stainless steel is comprised of a mixture of materials, primarily iron, chromium, nickel and in some cases molybdenum and manganese along
with other materials in small quantities. It is this unique blend that allows the special properties of corrosion resistance by formation of an outer oxide
protective layer, or "passive" film.
There is not agreement in industry as to exactly how the passive layer works, but it is generally agreed that the outer layer after passivation consists of only
oxides of chromium and iron or nickel which are highly resistant to corrosion. It is critical, therefore in passivating stainless steel that the material is very
clean and absent of free iron to form the passive layer upon oxidation. Cleaning the surface of all impurities is critical to make the surface ready for
oxidation (forming the passive surface).
Most companies have used and continue to use methods for cleaning and "passivating" stainless steel which utilize mineral acids such as nitric acid. Their effect
is limited to surface iron, although in many cases this method re-deposits contaminant iron on the surface again. Nitric acid is known to many times produce pitting
corrosion. There are many problems with long term use of mineral acid applications, especially under corrosive environments.
Although not really "new", an emerging technology that is proving to be a vast improvement over the mineral acids is the use of a safer organic pacifying solution
such as BioPas. BioPas is a very effective pacifying solution which complexes and removes a variety of metallic ions that would
otherwise adversely affect the corrosion resistance of the stainless steel. BioPas works in aqueous solutions to tie up metal ions so that they are
no longer effective or able to have a negative impact. After stripping the metal ions from the surface, the BioPas pacifying solution forms a water
soluble complex with a metal ion. It will not precipitate the metal ions again like the mineral acids are known to do.
By it’s very nature, BioPas is non-toxic, non-corrosive and biodegradable. BioPas is a natural pacifying solution based on citric
acid which is Generally Regarded as Safe (GRAS) for use in food products. It is a common material used in many food and beverages, including most of the carbonated
beverages sold on the market. This means that citric acid based BioPas is compatible with the environment and can usually be blended into sanitary
sewage systems with environmental agency approval.
Conversely, mineral acids such as nitric acid are corrosive by nature and they represent significant personnel hazards and threaten property as well. Heated, their
risk is intensified. After use, very careful handling is required. Expensive transportation may be necessary to dispose of the residues. In addition to being
corrosive, nitric acid is also an oxidizer which increases risk and expense. Eliminating the waste products can expose the user to long term liability under RCRA
and CERCLA.
BioPas represent the state-of-the-art technology that is highly effective in stainless steel passivation. The old constraints of mineral acids such
as nitric acid date back many years, and are no more effective now than when initially developed at a time when the chemistry of passivation was little understood.
With current technologies available for study of the surface chemistry of stainless steel we can see that it makes sense to choose a material that eliminates
the contaminants from the surface more completely and helps to produce a truly passive surface by giving the best chromium enrichment to the surface.
According to the experience we have gained over many years and other information at our disposal. We can categorically state that ScaleAwayBioPas does
not exert any harmful effects on personal health or the environment, provided that it is used properly,
BioPas is TOTALLY SAFE to:
You and your Staff
Your Products and Equipment
Our Environment