What is APEO? How to remove it from fabric?
What is APEO and what does APEO free mean? What are the bad effects due to the presence of APEO in finished goods or effluent?
Alkylphenol ethoxylates(APEO) are nonylphenol compounds(NPEO). APEO are non-ionic surfactants with an emulsifying and dispersing action, Which makes them suitable for very large variety of applications.
At the processing stage, approx.50% of APEO are used as emulsifiers for emulsion polymers based on styrol butadiene, Styrol acrylate, Pure acrylate or PVC systems.
Alkyl Phenol ethoxylates and especially Nonyl Phenol ethoxylates are considered to be very toxic for aquatic life. In Europe these emulsifiers/surfactants are no loner allowed/wanted.
Many surfactants give rise to environmental concerns due to their poor biodegradability, their toxicity (including that of their metabolites) and their potential to act as endocrine disrupters.
Concerns currently focus on alkylphenol ethoxylates (APEO) and in particular on nonylphenol ethoxylates (NPE), which are often contained in the formulations of detergents and many other auxiliaries (e.g. dispersing agents, emulsifiers, spinning lubricants).
Alkylphenol ethoxylates are themselves believed to be endocrine disruptors and to cause feminization of male fish. More importantly, however, they produce metabolites which are believed to be many times more potent as endocrine disruptors than the parent compounds. The most potent of these are octyl- and nonylphenol. Nonylphenol is listed as a priority hazardous substance under OSPAR and the EC Water Framework Directive, which means that any discharge needs to be phased out.
Identification of alternatives to APEO
With reference to the identified raw materials containing APEO contacts were established to the producers in order to find out if they were able to supply the same raw materials without APEO. The manufacturers have often developed APEO-free raw materials and these raw materials would be possible substitutes in the actual products without or with few adjustments in the product formulation.
Technical testing of alternatives
The technical testing of alternatives (APEO-free) raw materials or alternative surfactants is carried out at the Beck & Jørgensen laboratory or at the laboratory at EnPro.
The selection of new binder systems is dependent on the technical properties that can be achieved in the actual formulation. In the present project the aim is to replace four types of binders. In all four cases the options were reduced to two after the testing. It is essential to point out that substitution of the binder, which is the “backbone�? in the product, may require a number of adjustments or even reformulation. The dispersion aids and the binder system must be compatible in order to avoid flocculation. Replacement of the anti foaming agents may also be necessary to get the proper functionality. This means that substitution of other raw materials can be necessary even if they do not contain APEO.
As one binder is used throughout one product group it is not always possible to select the technically best alternative, since the consequence might be that a number of new binders/raw materials have to be introduced in the same product group.
The project demonstrated that it was (or would be) possible to substitute APEO and raw materials containing APEO. The substitution may be a long process, as many raw materials with different function have to work together. The aim was to remove APEO from the products and retain as much of the original formulation as possible, since development of new formulations is a more comprehensive time and resource consuming process.
The experience is that it is often impossible to get complete information about raw materials containing surfactants in advance.
Health and environmental assessment of alternatives
The health and environmental assessment was performed as a screening followed by a detailed assessment of groups of substances selected on the basis of the results of the technical testing:
Alkylether sulfate, sodium salt
Ethoxylated linear fatty acid alcohol (alcohol ethoxylates)
For comparison, the health and environmental aspects of APEO were presented.
Question: After finishing all processes, a fabric was tested and found to contain some APEO traces and the level of the APEO content present was not within the acceptable limits. Is there any proven method to remove the APEO content?
There are two simple treatments one can try.
Do hot soaping using a real APEO free surfactant, followed by 2 hot and cold washes.
Treat at 70°C with Formic acid 2gms/liter for 30 minutes, followed by 2 hot and cold washes.
One of the above processes will surely remove the traces of APEO content.