Pollutant contamination

The list of conspicuous chemicals is long and varied and is getting longer every day.
We are talking about fungicides, bactericides and antioxidants in Far East productions that are no longer permitted or desirable here.
In addition, the use of banned dyes, finishes and plasticizers due to ignorance of the facts is also a frequent cause of undesirable contamination.

Our knowledge base in this area changes almost daily.
Tests with contaminated samples are therefore the method of choice in any case.
Below are some remarks on the most important substance groups that we come across time and again in our daily work:

• Formaldehyde: is often caused by the use of incorrect catalysts in finishing processes for high finishing (to prevent shrinking).
  – We have developed reliable “recipes” that generally eliminate the problem simply and reliably.
• Disperse dyes (-orange/yellow): Often occur in the black shades of polyester.
  In older formulations, we have reliably succeeded in replacing the brominated functional groups with harmless iodized ones.
  In the meantime, however, there are also newer formulations that cannot be sanitized even with our recipes.
• Chromium VI: Chromium compounds are still an indispensable component in leather tanning and dyeing and are sometimes also used as a finish in normal wool dyeing.
  Under certain atmospheric conditions (low tuft humidity), toxic chromium VI compounds are formed.
  As chromium VI compounds are converted into chromium III compounds in the presence of water, remediation appears very simple at first glance: – spraying with water.
  However, measurements in the past have shown that this reaction is reversible, i.e. for sustainable remediation it must be ensured that the remediation process is irreversible by additionally fixing hydrophilic finishes or harmless reducing agents.
  This means that the new test regulations (reduction of the limit value to 2ppm, additional ageing test) can also be fulfilled.
• PAHś = polycyclic aromatic hydrocarbon compounds, such as naphthalene (moth repellent) and DMFu, generally have the unpleasant property for the renovator that they cannot be removed either by washing (with water) or by conventional chemical cleaning methods.
  (and are therefore often used by manufacturers for permanent finishes).
  We have developed special addition reactions with which we can convert many PAHś into water-soluble substances and rinse them out.
  A sampling test is always advisable, especially for problems with this group of substances.
• Heterocyclic compounds such as quinoline (quinoline) and its derivatives are also occasionally used as fungicidal or insecticidal additives in Far Eastern textile production.
  Here it is necessary to determine the appropriate chemical (by washing or spraying) or physical remediation method (in an industrial oven, steam pressure, spray tumbler) based on the specific properties of the pollutant identified.
• other solvents such as DMFa, ester compounds etc. are being used more and more, in particular because of the lower odor pollution during processing, as this reduces the pollutant load for employees in the processing process (the workplace concentration of solvents).
  However, this noble goal often has an unpleasant side effect: after packaging in polybags, the solvent that has not yet leaked out of the product continues to evaporate.
  As a result of solvent reabsorption or the conversion of odorless chemicals into odor-active ones, the buyer is greeted by an unpleasant waft of odors after opening the bag.
  Although this odor dissipates after unpacking, it reappears after repackaging.
  There are various options for degassing here.
  Annealing in the oven is only one option; sometimes additional chemical measures are also required.
• Phthalates: are mostly used as plasticizers and elasticizers in prints.
  They can possibly be rinsed out and replaced in their function by harmless kerosenes.
• Azo dyes: Direct remediation by conversion is the exception here.
  (In the case of azo dyes, we have only succeeded in doing this once for 5 of the 36 groups.
  More often, however, it is possible to bleach away the dye by oxidizing or reducing it and to overdye it with REACH-insensitive dyes instead.
  Encapsulation is generally prohibited with regard to the test methods used.
• APEO: There are ecological concerns about the use of alkylphenol ethoxylates, as APEO itself and its metabolites in wastewater are harmful to fish.
  Furthermore, studies have shown that APEO and its metabolites may have an estrogenic effect and can influence the hormone balance of living organisms even in small quantities in wastewater.
• The same applies to NPEO, as nonylphenol ethoxylates are broken down in sewage treatment plants to form 4 – n -nonylphenols, which have a toxic effect on many plant substances.
  Significant quantities of these are released into the aquatic environment during industrial processes.
  The hormone-active (estrogenic) effect on aquatic organisms together with the high bioaccumulation (>1000) is also the problem here.
  For consumers, however, the articles examined do not actually have any directly harmful effects on health.
• Despite this list, there are still many other undesirable substances.
  These include organotin compounds and neutral surfactants, which have an undesirable effect on human hormonal cycles, as well as bacterial substances. Ask us on a case-by-case basis!