FAQ

SYSTEMK4 is an environmentally friendly and absolutely safe cleaning process. The basic component of SYSTEMK4 is a halogen-free solvent. It is designed in such a way that, when properly used, it does not pose a risk to air, water, human beings and soil. And here lies the huge innovative potential of SYSTEMK4: The cleaning effect of the solvent SOLVONK4 is the same as perchlorethylene, and sometimes even better. At the same time, SOLVONK4 is not classified in Europe as either a hazardous material or a hazardous substance! Moreover, SOLVONK4 is biodegradable and has been tested dermatologically with the result “Very Good”.

In October 2010, we presented SYSTEMK4 to the public at the trade show ExpoDetergo in Milan. The international textile cleaning trade is very interested in SYSTEMK4.

The statements made in our information brochures have been confirmed not only by our own preliminary tests but particularly by feedback from practical experiences. In the internet and in various social networks, users express a high degree of satisfaction with their experiences and promote SYSTEMK4 independently on their regional markets as the most eco-friendly textile cleaning procedure in solvent cleaning.

More than 550 SYSTEMK4 cleaning machines in 22 countries only 2.5 years after the market launch – a clear proof of the success of the environmentally compatible cleaning procedure SYSTEMK4!

Quality that is obvious.

SYSTEMK4 features the same – for some textiles even better – cleaning properties as perchloroethylene.

Lipophilic and in particular water soluble soil is excellently removed. Even saline (salt based) soil is removed better with SYSTEMK4.

Definitely the right solution.

When developing SYSTEMK4 we focused on the needs of all parties. Our goal was to develop an effective system from which all would benefit – from the cleaner to the shop assistant to the end customer. This is the only way for us to ensure long-term success and together look forward to a secure future!

Along with the already mentioned advantages, SYSTEMK4 offers numerous further advantages for…

…all parties:

SYSTEMK4 is tested and dermatologically absolutely harmless. SOLVONK4 is more powerful than all the previous cleaning technologies. Due to it being free of hazardous substances (according to the CLP-Regulation) and its favorable general categorization (by GHS), it is quickly and fully accepted by colleagues, clients, landlords and authorities.

…dry-cleaning entrepreneurs:

In some places operating dry-cleaners with PER solvents is already prohibited (e.g. in supermarkets in Germany) or will be prohibited in the near future (e.g. California in 2020). As opposed to perchloroethylene SYSTEMK4 offers a long-term solution for the dry-cleaning business – and that with powerful cleaning effect and no compromises.

Since SYSTEMK4 is not a hazardous material, delivery is fast, uncomplicated and logistically unlimited. Capital commitment and extensive stock keeping are a thing of the past! With SYSTEMK4 costs and effort for intense training sessions are unnecessary. This reduces risks and improves your budget!

…employees in dry-cleaning businesses:

SYSTEMK4 ensures safe and easy working. The effort for spotting is greatly reduced.

…end customer:

SYSTEMK4 offers customer, who are reluctant to have expensive clothing dry-cleaned, a real alternative. Because unpleasant odors are a thing of the past. Textiles cleaned with SYSTEMK4 are absolutely odorless. An important aspect for persons who are very sensitive to odors.

One system – multiple advantages!

SYSTEMK4 is an innovative and highly efficient cleaning procedure for the commercial textile care for which we have applied a patent worldwide!

We have put a considerable amount of work and financial resources into this invention. Patents are property rights. Companies publish their inventions and own said property rights in the claimed countries after the patent has been granted. To compensate for the financial burden, the property right owners usually charge high royalty fees for the use of their patent.

We abstain from charging royalty fees for the use of SYSTEMK4! We want to offer everyone the opportunity to convert to the environmentally compatible and powerful cleaning procedure without the financial burden of royalty fees – because environmental protection concerns all of us!

For our customers, this means that they can use SYSTEMK4 free of any charge. This use, however, is free only in connection with our SYSTEMK4 products because the reliability and safety of the cleaning procedure is ensured only if our system products are used.

Both the solvent SOLVONK4 and the dry cleaning detergent CLIPK4 were tested for their skin compatibility by an independent test institute.

Both products received a „very good“ test result so that the risk of skin irritations can be excluded for healthy skin.

This positive test result gives the cleaning companies, their employees and their customers a greater deal of safety.

So far, there is no international care label according to ISO 3758 for SYSTEMK4; for this, the time after its introduction in October 2010 was simply too short. The awardance of an international care label according to ISO standards is a long way. Typically, several years pass between the application and the awardance of a care label.

On 10 April 2013, EFIT started a research project: „Study on the behaviour of new solvents for textile care in cleaning and aftertreatment as compared to the traditional solvents perc and hydrocarbon solvent“.

Already during the preliminary discussion there were signals for the tendency to assign SOLVONK4 to the care label "P" which comprises the label "F" – with this assignment, SYSTEMK4 would have covered the solvent cleaning completely at one go.

In order to get a personal impression of SYSTEMK4 in practice, our technical department in Wiesbaden will be pleased do demonstrate the capabilities of a 15 kg cleaning machine. You can also bring along your own textiles for a sample cleaning. Interested parties are welcome to visit us! However, we kindly ask you for a prior arrangement by telephone to allow us to coordinate your visit optimally. We also offer regular trainings on SYSTEMK4. Training dates

We would also be pleased to arrange your visit in the cleaning facility of one of our customers.

While we generally see ourselves as partners of the engineering industry, we prefer to assume a neutral position with regard to technical issues on machine technology. There are several arguments that need to be considered. With older cleaning machines, the technical effort required can usually not be justified. There are also legal issues to be considered, e.g. guarantees or machine approval for certain solvents.

Most manufacturers answer this question generally with a „No“. So far, BÖWE is the only company to offer conversion kits for certain machine types. By querying type and serial number or version, the machine partner can answer these questions best.

When it comes to a possible conversion to SOLVONK4, the operational safety must never be compromised. The essential modifications of parameters concern the period during and at the end of the drying process when it is important to minimize the residual solvent concentration. The challenge for machine manufacturers lies in building extremely low-emission machines. SYSTEMK4 has certainly pushed the development in the field of cleaning machine technology a large step forward!

The batch times for two-bath cleaning procedures using SYSTEMK4 are usually within the range of one hour. Most machine manufacturers now offer SYSTEMK4 machines that have been approved for various halogen-free solvents according to the manufacturer’s specifications. Installation and operation of such cleaning machines ensure and preserve utmost independency and flexibility for the cleaning companies. An investment in SYSTEMK4 cleaning technology is therefore not a one-way street, and the technical equipment of these machines would ensure reliable compliance with the required limit values, e.g. for hydrocarbon solvent in Germany, when switching to some other solvent.

SOLVONK4 – the halogen-free solvent.

SOLVONK4 has very different properties from conventional solvents in dry-cleaning. It is a halogen-free, organic solvent with a pureness of > 99 % and excellent cleaning performance.

The innovative solvent is not only able to dissolve and absorb lipophilic (fats, greases and oil) but also hydrophilic soil (water soluble soil). Besides the excellent cleaning power of SOLVONK4 the cleaned textiles also have a pleasant and smooth feel. Noticeable is also minimized fiber abrasion during the cleaning process and also less creasing. In Europe SOLVONK4, similar to HCS respectively cyclosiloxane D5, underlies the VOC directive, in Germany implemented by the 31st Federal Emission Protection Ordinance (BImSchV). According to the current status of legislation in Europe SOLVONK4 is neither a hazardous material nor a hazardous substance! Even after the, as of December 2010, for materials valid CLP classification SOLVONK4 still does not require any hazardous labeling on the European market. SOLVONK4 is biodegradable and dermatologically tested with “Very Good“.

The named properties in combination with a very favorable classification within the framework of the Ordinance on Hazardous Substances are unique and have not been achieved in the past. The results of pre-market-tests demonstrate that SOLVONK4 has the potential of becoming a paradigm for dry-cleaning.

All advantages at a glance:

• Halogen free.
• Pureness > 99 %.
• Excellent cleaning performance – effective against lipophilic AND hydrophilic soil.
• Easy fi nish and pleasant feel.
• Neither a hazardous material nor a hazardous substance in Europe (CLP).

The solvent SOLVONK4 has a characteristic odour. The odour threshold, i.e. the concentration beyond which DBM can be percepted, is very low, within the range of only a few mg/m³. Most other solvents have a characteristic odour as well.

End consumers expect perfect, stainless and optimally ironed garments with a neutral odour. Since its market introduction, the odour of the solvent has been subject of intensive and controverse discussions. In practice, the emission of odours upon unloading the cleaned textiles is very low, and when they are put on hangers, the odour is not or hardly perceptable anymore.

The discussion is therefore limited to the area of the shoulder pads. However, when the drying parameters have been optimally adjusted, textile odour is very low or even nonexistent even before the finishing process.

However, unwanted odour issues may arise the cause of which is not the solvent but an incorrect setting of the machine parameters or inadequate servicing of the cleaning machines. For details on how to address this kind of odour issues, please refer to "How can odour problems be eliminated?".

Characteristics and classification of solvents in comparison

For determining physical data, we asked a university specialized in such issues to evaluate the data at their physical institute. A multitude of characteristics were determined, e.g. surfactant solubility and other relevant data such as evaporation entalphy, one of the performance characteristics for the expenditure of energy during distillation.

The investigation showed that a vapour pressure of approx. 2.7 bar (the typical vapour pressure value is 4.5-5 bar) is sufficient for distillation. SOLVONK4 is therefore easily distilled.

There is a multitude of determination methods for measuring the flash point of organic solvents.

The Pensky-Martens closed cup (PMCC) measurement of the flash point is the most common method for organic solvents and was previously taken as the basis for classifying combustible liquids (VbF class A III, not water-miscible, flash point requirement for this class currently > 60 °C PMCC).

The flash point of SOLVONK4 is 62 °C. Independent certified analytical laboratories confirmed a flash point of 64.5 °C PMCC for SOLVONK4.

The flash point determination based on a standardized method of measurement depends crucially on the purity of the solvent to be examined. In chemical databases, e.g. GESTIS, and other sources that are accessible via the internet, one sometimes finds physical data such as flash points whose origin is not mentioned. It should be mentioned that the majority of this previously determined data comes from a time when DBM was used only as an internal intermediate product for further synthesis in technical quality or if the technical purity was completely satisfactory for further applications. SOLVONK4 is a DBM with a purity of > 99%. Analytical results of production batches usually show purities of 99.5% and higher. Differences can also be explained by the fact that some data was measured while other data was determined via model calculations.

We offer users of the SYSTEMK4 cleaning technology a free flash point measurement of clean solvent samples extracted from the pure tank!

On demand, our technical service will provide you with suited 250 ml sample containers at no charge. The shipping of the properly declared and sealed solvent samples is chargeable to and at the risk of the customer. The analytical result is delivered to the customer by means of a certificate upon completion of the measurement. This is accepted in the case of an inspection by the supervisory authorities. The cleaner therefore always has evidence for the fulfillment of his internal supervisory duties.

In Germany, we also offer this service as part of the DTV book of vouchers.

• Unclean new machines.
• There is no second reduction valve installed (drying 4.5 bar / distillation 2.4 bar).
• Distillation temperatures set too high in the machine parameters.
• Distillation separator does not automatically refill water.
• Filter cartridges are replaced at too long intervals or not at all.
• Poor maintenance (particularly water separator).
• Single-bath procedure with liquor recirculation into working tank as standard procedure.
• Insufficient drying.

• Check distillation parameters and readjust them if required.
• Clean water separator and tanks.
• FMB water separator requires Icon 50 for emptying.
• Filtrate solvent using ADSORBON.
• Distill solvent.
• Use PERAMON.
• Regular maintenance. Machine care maintenance schedule

Due to the different definitions and regulations in the individual countries, it is very difficult to make statements on this subject that apply generally. The question whether an organic solvent is subject to a VOC regulation must be answered individually for each country.

Europe – VOC directive 1998/13/EG (VOC = Volatile Organic Compound)

SOLVONK4 is a halogen-free organic solvent and subject to the VOC directive within the EU. The EU member countries have implemented this directive into national law.

The VOC Ordinance in Europe stipulates that a limit value of 20 g solvent loss per kg of cleaned textile must not be exceeded.

This does not automatically mean that cleaning machines emit 20 g solvent per kg of cleaned garment into the atmosphere. The major portion of the solvent loss – or in other words: the necessity to refill solvent – results from the fact that sludge from the distillation container is pumped off in a highly viscous but still liquid form into the disposal container. The solvent content of these liquid disposal residues is approx. 35-45%. Other liquid components in the residue are oils and fats (skin fats) from the clothing and surfactant residues from the cleaning enhancer. Solids also originate from the dirt (e.g. fluffs, fibre abrasion and usually high proportions of pigment dirt). These distillation residues are collected by certified disposal companies to be recycled or thermally recovered.

In the EU, there are standardized waste code numbers for the halogen-free distillation residues or sludge from SYSTEMK4 cleaning facilities. The most common waste code number is EC 140 603. This code number is identical with the waste code numbers for other halogen-free distillation sludges, e.g. residues from hydrocarbon solvents.

To prove that the legal limits are not exceeded, the textile cleaner is obligated to provide a solvent balance:

Difference of solvent in machine tanks and filters
+
purchased or refilled solvent including any VOC content of the used auxiliaries
−
calculated solvent loss from sludge disposal (based upon a certificate the cleaner receives from his disposer)
=
solvent loss for the period of one year.

To quantify the solvent loss in kg, the solvent volume must be multiplied with the density of the solvent (for SOLVONK4: 0.835 g/ml according to Chapter 9 of the safety data sheet).

This value must then be divided by the total weight of the cleaned textiles within the period under consideration.

Normally, this calculation will result in a value between 4 and 10 g solvent loss/kg textile. If the textile cleaner cannot weigh each cleaning batch, the counted cleaning batches at the counter (without the count of elapsed service programs) of the machine can be multiplied with a realistic load factor of 60–70% of the machine capacity to determine the approximate weight of the annually cleaned textiles.

Since it may not be possible to determine the solvent content for each residue container, supervisory authorities accept a realistic mathematical solvent content in the residue. Currently, this value is 60% by weight. When in doubt, please enquire the value from your competent authority. In the course of a review of the Solvent Emission Directive (SED) in Great Britain, there is a discussion about reducing this value to 50% by weight solvent content in the residue.

According to currently available experiences from practical operation of SOLVONK4 machines, a solvent loss in the order of 0.4–0.6%, with regard to the weight of the cleaned textiles, is to be expected.

While this also depends on the operating conditions, the solvent loss is in any case less than 1% by weight of the cleaned textiles.

If the residue is reduced due to drastic distillation conditions, there is an increased risk that unpleasant odours overdistill back into the solvent or that steam-volatile odorous substances contaminate the solvent when direct steam is blown in. With an expected disposal of 1 or at most 2 barrels per year – with regard to an average machine capacity of approx. 16 kg –, the relatively low solvent loss is acceptable.

Germany

The European VOC Ordinance has been implemented with the 31. BImSchV (Ordinance on the Curbing of Emissions of Volatile Organic Compounds). Like any other halogen-free VOCs in Germany, SOLVONK4 is subject to this ordinance. It is imperative to comply with the limit according to Annex III Nr.3.1.1 of 20 g solvent loss/kg of cleaned textiles.

In Germany, „special requirements“ are to be met according to Annex III, Nr.3.1.2 of the 31. BImSchV which are expressely related to hydrocarbon solvent. It is imperative to comply with a limit of 5 g hydrocarbon solvent/m³ at the end of the drying process and to document this compliance with the limit at the request of supervisory authorities. Furthermore, hydrocarbon solvent machines are to be operated in such a way that the mass concentration of volatile organic compounds in the extracted, raw exhaust gas does not exceed 0.15 g/m³, averaged over the drying and blow-out phase.

These „special requirements“ for hydrocarbon solvents which apply only in Germany do not apply to SOLVONK4! By its chemical structure, SOLVONK4 is not a hydrocarbon, and according to the current state of the German Hazardous Substances Ordinance / CLP Regulation in Europe, SOLVONK4 is also not a hazardous substance. There is no limit for SOLVONK4 that is bound to compulsory surveillance at the end of the drying phase.

Switzerland

Switzerland controls VOC emissions via the VOC incentive tax which is a positive list that obliges the importer to pay said tax upon entering the country via the assigned customs tariff number.

We contacted the competent authority and obtained an exemption from the VOC incentive tax for SOLVONK4 as well as for VINOYK4.

USA

In the USA, dibutoxymethane is also a VOC according to the definition of the EPA. In California, dibutoxymethane does not appear in the list of approved exemptions and is therefore also rated as a VOC.

For these halogen-free distillation residues or sludges from SYSTEMK4 cleaning facilities, there is the uniform waste code number EC 140 603 in the EU. This waste code number applies to all halogen-free distillation sludges (e.g. hydrocarbon solvent residues).

The solvent content of these liquid disposal residues is approx. 35-45%; the residues are collected by certified disposal companies to be recycled or thermally recovered. Other liquid constituents in the residue are oils and fats (skin fats) from the clothing and surfactant residues from the cleaning enhancer. Solids also originate from the dirt (e.g. fluffs, fibre abrasion and usually high proportions of pigment dirt).

We generally recommend the disposal of waste or of distillation residues according to EU standards also for counties in which such disposal of waste from textile cleaners may not be subject to statutory control.

A 20 kg textile cleaning machine produces an average of approx. 5-8 litres of contact water per day. Since the textiles are overdried in modern low-emission cleaning machines, the majority of the contact water originates from the textiles. The water or moisture content of an average cleaning batch amounts to approx. 3-5% by weight, related to Central European climate.

This contact water must be treated or disposed of in accordance with the applicable local provisions. In order to assess whether this contact water can be introduced into the public sewer system, the textile cleaner should contact his competent supervisory authority. Since cleaning machines and the operation thereof are usually subject to compulsory notification and the authority requests at least the safety data sheet of the products used and data on the cleaning machine, the issue of contact water should be addressed on that occasion.

In order to perform a risk assessment with regard to the generated contact water from cleaning machines, the solvent content of the contact water was determined by a certified laboratory. For this, a SOLVONK4 sample and the double amount of water were vigorously shaken and then left to stand for a week. The determination of the solvent content and of all oily or fatty constituents in the water phase was carried out using a measuring method that is common in the waste water analysis according to DIN EN ISO 9377-2-H53 and resulted in a value of 3 mg/l.

Because of this low solvent content in the contact water, the very favourable rating according to the German Hazardous Substances Ordinance, the positive classification WGK 1 according to the German water hazard class and under consideration of this minimal total volume generated per working day, we see no danger in introducing the contact water into the public sewer system when the contact water has a clear appearance. As described in its safety data sheet, SOLVONK4 has been classified as biodegradable.

In Germany, Annex 55 of the German Laundry Ordinance sets the limits for oils and fats in the commercial waste water to 20 mg/l of waste water. The analysis result of a water solubility of 3 mg SOLVONK4/l of contact water would therefore stay far below the limit applying to commercial laundries for introducing contact water into the public sewer system and thus complies with the discharge conditions for commercial waste waters applicable in Germany.

The contact water generated in SYSTEMK4 textile cleaning machines must be treated in the respective countries in compliance with the applicable legal requirements.

Molecular formula: C9H20O2; Average molecular weight: 160.25 g/mol.

In Europe, CAS 2568-90-3 REACH has been preregistered and will be registered with the European Chemicals Agency (ECHA) in Helsinki by 1. June 2013. We have considered and reported the intended applications of DBM required for the registration, from the industrial application to the applications of our customers in their operations.

Acetals can be defined chemically as a special case of diether compound; however, they differ from classical ethers with regard to their structure, synthesis and chemical/physical characteristics.

The characteristic feature of the acetals is the chemical bond known in chemistry as acetal bond. In the organic synthesis, acetalization is used for the protection of reactive centres in a molecule during a reaction step.

The acetal bond is a bond type of the organic chemistry occurring very frequently in nature. The best known examples can be found in sugar chemistry. The structure of builder compounds in plant matters such as wood or cotton, more precisely the formation of cellulose (the basic monomer unit of cotton is the cellobiosis, here in ß-glycosidic bond) or as energy store such as starch (ἁ- glycosidic bond), also shows the characteristic acetal bond.

Acetals are known for their stability in the neutral and alkaline medium.

As is well known from washing cotton fabrics, the acetal bond in an alkaline environment is very stable. In acids, e.g. when removing rust stains, the cotton can be damaged and its tear strength can be impaired due to the lower degree of polymerization.

Characteristic for acetals is their high stability throughout a very wide pH range of approx. 4-14.

In acidic environments as well as in the presence of water and of heat, acetals are cleft by hydrolisis. However, these conditions are completely uncommon in solvent cleaning. In all other solvent cleaning procedures as well, care is taken for the protection of the cleaning machines to ensure that the pH in the solvent and the contact water of the facilities is not shifted into the acidic range.

In cleaning machines, an acidic pH can damage the ay protective layer of the copper cooler which results in a phenomenon known as “blueing” of the water separator caused by copper corrosion. The blue colour of the water phase in the water separator is caused by the water-soluble copper tetramine complex, a clear indication of copper corrosion in the machine. The problem is eliminated by adding PERAMON and by performing a routine check on the pH value.

If copper corrosion occurs in cleaning machines for any reason, the pH of the solvent must be checked and neutralized if required. The blueing itself has no effect on the cleaned textiles. To avoid pitting in the cooler on a long-term basis and to exclude the risk of coolant water entering the solvent, the damaged cooler should be replaced.

The worldwide most frequently used solvent perchloroethylene is alkaline-stabilized. The alkaline stabilizer that is added to fresh perc or to regenerated perc of good quality neutralizes introduced acids and protects the perc from auto-catalytic decomposition. When the stabilizer is used up over time and the pH value in the water phase has been decreased, restabilization is required, and it may then also be necessary to neutralize the solvent.

Another reason for the decrease of pH in the solvent, particularly in perc cleaning, may be excessive vapour pressure (> 4.5 bar) in steam-heated machines. Therefore, the vapour pressure of the machines should be checked regularly. The installation of a steam reduction valve and setting the vapour pressure limit to approx. 4.5 bar immediately before the entry into the still usually solves the problem very quickly.

SOLVONK4 is adjusted slightly alkaline during the production. The solvent is neutralized after the synthesis. The other SYSTEMK4 products are also adjusted to a slightly alkaline pH value.

We recommend the use of PERAMON for solvent care in the distillation. PERAMON neutralizes the acids introduced into the still that may enter e.g. through dirt or skin fats. PERAMON also contains anti-corrosion additives and odour absorbers that eliminate unpleasant scents. PERAMON ensures hygiene conditions in the solvent and in the cleaning machine!

Here you will find the recommended dosages and applications for PERAMON.

Illustration: Steam  pressure curve SolvonK4 - Dibutoxymethane; taken from: J. Chem. Eng. Data  2000, 45, 988-990 [M. P. Tulinska et A. M. Szafranski]

Own measurement results of the equilibrium vapour pressure curve of highly clean SOLVONK4, carried out by a certified analytical laboratory, showed a measured vapour pressure of 0.78 hPa at 20 °C.

This value is very close to the calculated vapour pressure value from the bibliographical reference. We will be pleased to provide you with the complete test report with all measurement data of the equilibrium vapour pressure to the boiling point of DBM (SOLVONK4).

For the other major physical data of SOLVONK4, please refer to the safety data sheet.

For trade associations, health insurances and regulatory authorities, the question arises as to the necessity of setting up emission limits or occupational exposure concentrations to protect man and the environment.

Measurements taken in the cleaning machine drum at the end of the drying phase, carried out at FMB in Bologna, showed steam concentrations of 350-400 mg SOLVONK4/m³. All measurements were taken using a calibrated measuring device.

When comparing the solvent vapour concentrations mentioned above in the cleaning drum at the end of the batch to the limits applicable in Germany according to the 2. BImSchV for perchloroethylene of 2000 mg perc/m³ or with the limits applicable according to the 31. BImSchV for hydrocarbon of 5000 mg hydrocarbon solvent/m³, it is indisputable that SYSTEMK4 cleaning machines are very low in emissions according to the state of technology.

Perchloroethylene as well as hydrocarbon solvent are classified as dangerous substances according to the German Dangerous Substances Ordinance and have accordingly limits that are bound to compulsory surveillance.

There are no emission limits for SOLVONK4 that are bound to compulsory surveillance!

With such low vapour concentrations in the cleaning machine drum, there is absolutely no reason to set emission limits according to the current version of the Dangerous Substances Ordinance.

We asked an analytical laboratory that specializes in air sample measurement to have the room air analyzed during the cleaning process of a SYSTEMK4 cleaning machine in the technical department in Wiesbaden. Individual-related room air samples were taken with previously calibrated air sample collectors in the pressing room, during operations at the cleaning machine and furthermore statically immediately above the cleaning machine loading door. The analytical laboratory reported a time-weighted average of less than 5 mg SOLVONK4/m³, related to 8 working hours. At this point, it should again be recalled that there is no room air-related limit for SOLVONK4 or DBM.

The dissertation of C. M. Freitas Dinis of Bergische Universität Wuppertal, July 2001, deals with the degradation of dialkoxymethane in the atmosphere. The atmospheric lifetime of dibutoxymethane is given in table 19 on page 86 as 8.2 ± 1.1 hours. Therefore, the primary degradation of dibutoxymethane in the atmosphere happens very fast. The degradation products are far more water-soluble than the solvent itself and are either washed off with the rain or further degraded in the atmosphere via intermediate products.
For further literature data on the characteristics of a multitude of alkoxyalkanes, please refer to the EFSA Journal (2004) 107, pages 1-59, published by the scientific council for food additives, aromas and materials that come into contact with foodstuff.

The synthesis of DBM makes formaldehyde react with butanol using acidic catalysts. After the production, the generated product is neutralized and purified using distillation to a content of > 99 %.

When the question arises whether formaldehyde from the production process remains, one must first consider the boiling points of the two substances. At temperatures above -19 °C, formaldehyde is a gas. SOLVONK4 (DBM) boils under normal pressure at 180.5 °C. With a boiling point difference of almost 200°C, the formaldehyde concentration is extremely low to unverifiable.

For formaldehyde, there is a natural background presence, e.g. in inner rooms, that lies, according to a US bibliographical reference, between 0.03 and 0.07 mg/m³. Due to advanced analytics, there is still a clear zero in the minority of cases. It is generally a matter of analytical efforts that allows the quantification of minimal concentrations in the area of trace analysis.

Theoretically, the possibility of released formaldehyde given the said acetal structure exists. Formaldehyde is a dangerous substance and has different limits in various countries that are defined for a time-weighted 8 hour workplace average. The German Research Foundation suggested a limit that was set to 0.37 mg formaldehyde/m³.

The air samples collected in Wiesbaden at three measuring points during the cleaning process showed in all cases values that were significantly below the suggested time-weighted workplace average. The question as to whether the formaldehyde concentrations measured as just above the natural background presence originate from the room itself (wood, plastic coatings, paints etc.), are emitted from the clothing (wrinkle-resistant finishing, easy finish, wash-and-wear finishing), were contained in the solvent or were created only due to thermal load, e.g. during drying, can be answered in this concentration range only with an enormous analytical effort.

We contacted the trade association responsible for textile care (BG-ETEM) on our own initiative already at an early stage and forwarded them addresses in consultation with selected customers. We also provided the trade association with the measurement results determined by our external test laboratories.