FORMALDEHYDE, CERAMIC PRODUCTION AND ENVIRONMENTAL IMPACT: AN OVERVIEW ON A CONTROVERSIAL COMPOUND
The Italian ceramic industry has been involved for years in a very important goal: the reduction of environmental impact on the territory within which it operates. For this reason it is constantly tested in order to prove its right performances as well as to ensure compliance with the strictest standards.
In this perspective, the areas which are usually taken into account are:
water balance, use of materials, energy consumption and atmospheric emissions.
The latter are the main issue on which the attention of legislators, industry and institutional research has been focused for a long time and, within this area, the most important compounds that the ceramic sector has to constantly check are listed here:
► Particulate matter
► Volatile Organic Compounds
► Aldehydes and Formaldehyde
► Nitrogen Oxides
► Sulphur Oxides
Given these categories, which is the role and what are FORMALDEHYDE’s features?
THE CHEMICAL POINT OF VIEW
From a chemical point of view aldehydes are an important class of organic compounds characterized by the presence of chemical group C = O, so called Carbonylicgroup.
[A chemical group is an atom or groups of atoms that impart specific chemical properties, mostly reactive, to all those compounds that contain them]
Formaldehyde [CH2O] belongs to aldehydes’ category and it is for sure the simplest of that type. It stands out for its high reactivity, biodegradability, high boiling point and high water solubility.
WHERE CAN WE FIND IT?
It is a naturally occurring substance in the form of colourless gas and, according to its high water solubility, it can be used in aqueous form as well. In both cases it is characterized by a pungent smell, certainly unpleasant.
It is produced in natural manner by some combustion processes and by the oxidative metabolism of al lot of living organisms. Even humans produce unknowingly ridiculous amount of formaldehyde.
It is surely one of the most common chemicals and it is present in almost every environment, including in the household.
It is produced in more significant quantities by car exhausts, some kind of heaters, incinerators as well as by cigarette smoke. It can also be found into paints, dyes, cosmetics, conditioners, shampoo, hairsprays, nails’ products, smoked or fried food and, in very low percentages, in vegetables and fruit.
FUNCTIONS AND INTENDED USE
Formaldehyde, tanks to its features, can performs various functions and for this reason it is used in rigid regulated concentrations in many different areas of which we list below as an example the most relevant.
- Having a powerful bactericidal action, it is used in hospitals (formalin), in aqueous solutions of domestic sanitizers and in textile’s industrial production
- It is primarily used as a food preservative (additive known as E number 240)
- Added to other compounds, it can be found in sound-absorbing ceilings and in binders for chipboard or laminate wooden panels (therefore, in general, in furnishing)
- By reaction with phenol, it polymerizes giving rise to Bakelite
- It is finally used in textile dyeing processes in order to ensure stability to all the solutions
CRITICAL ISSUES AND TOXICITY
Despite its widespread use, formaldehyde has also toxic features that impose to pay carefully attention during manipulation and a correct procedure in case of massive inhalation or contact.
The exposure to formaldehyde occurs mainly by breathing.
The amount that can be ingested with a normal diet or absorbed through the skin is, in fact, entirely negligible.
Among the immediate effects that can occur after a personal exposure to high formaldehyde’s percentages, airways and ocular irritation, tiredness and skink rash are the most frequent.
In recent times, and more precisely in 2016 January 1st, formaldehyde has been definitively classified as a carcinogen.
FORMALDEHYDE AND CERAMIC PRODUCTION:
The formaldehyde’s carcinogenic nature has led the laboratories in charge of the emissions’ analysis to separate and measure it separately from other aldehydes in order to circumscribe its presence and precisely identify its percentages in the air.
As we know, the use in the ceramic field of specific solvent-based products within the digital decoration process (inks and glues above all) causes, during the firing cycle, the emission of substances that impact not only on the olfactory perception but also on the air quality in terms polluting agents.
Although the values are constantly monitored and the ceramic district is showing a constant and rigorous attention in containing and complying with the limits laid down by the provisions in force, the research and the development of alternative solutions that can improve producers’ standards and performances represent currently the first goal in the agenda of several companies involved in the sector’s production supply chain.
In this perspective, the tendency towards the replacement of specific products with low-invasive alternatives - which is still today timid and not predominant - seams to be played around the Water Based topic. A complex issue that is both in evolution yet inevitable.
The use of water-based digital inks and glues within the digital process has submitted evidence about the important decrease in SOV, aldehydes, formaldehyde and organic acid emissions, responsible for the poor air quality. Their different chemical formulation, in fact, acts on the reduction of the problematic substances.
Without entering in complex technical details, we could simplify it as follow:
The formulation has been developed in order to get the best combustion as possible during the firing cycle; a feature that is determined by the chosen polar solvent whose molecules - unlike those non-polar used within solvent-based digital inks and glues - burned more easily into the industrial kilns.
Water-based digital inks are also characterized by a water content that correspond to the 40-50% of the liquid phaseand therefore by a reduction of the 40-50% of the liquid organic components to which the over mentioned environmental problems can be assigned.
(Learn more watching the short video about polluting and odorous emissions)
In general, we could end by saying that even though the district has already achieved great heights, it is also to be hoped the implementation in near future of all those actions that can further improve the quality of the air we breathe.
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