Surfactants (organic polar compounds with at least one hydrophobic part and at least one hydrophilic

group) are widely spread in textile finishing industry. All types of surfactants (anionic, non-ionic,

cationic and amphoteric) are in use. However, anionic and non-ionic dominate. Surfactants in textile

industry serve mainly as detergents, wetting agents, deaeration agents, levelling agents, dispersing

agents, softening agents, emulsifying agents, spotting agents, anti-electrostatics, aftertreatment agents

for fastness improvement, felting agents, fixing acceleration agents for continuous dyeing and

printing.

Surfactants can be the essential active part of a textile auxiliary or used as an additive in textile

auxiliaries or dyes, printing pastes and coating pastes (dispersing agents in dyestuffs, emulsifiers in

preparation agents etc.).

Following chemical components are mainly in use:

Anionic surfactants:

alkyl sulfates, alkyl ether sulfates, alkane sulfonates, alkyl aryl sulfonates, fatty acid condensation

products, alkali salts of fatty acids (soaps), lignine sulfonates, condensation products of formaldehyde

and naphthaline sulfonic acid.

Non-ionic surfactants:

hydrophilic part: polyethylenoxide or polypropylenoxide; hydrophobic part: fatty alcohol, fatty amine,

fatty acid amide, fatty acid, alkylphenol, alkylnaphthol.

Cationic surfactants:

derivatives of quaternary ammonia salts.

Amphoteric surfactants (very rare):

Betain derivatives.

Due to their surface activity, aquatic toxicity of surfactants has to be taken into account. Fish toxicity

between different types of surfactants can vary within a large range. For non-ionic surfactants with

increasing ethylene oxide part, fish toxicity decreases but biodegradation decreases also [Schöberl,

1988; Stache 1990]. Cationic surfactants have by far highest fish toxicity compared to other classes of

surfactants.

The rate of biodegradation also strongly depends on the chemical structure of the surfactants. For nonionic

surfactants chain length and number of side chains is a crucial point.

Substances with a low rate of biodegradation/bioelimination are adducts of ethylene oxide and

propylene oxide (EO/PO´s; mainly used in preparation agents), lignine sulfonates and condensation

products of naphthaline sulfonic acid and formaldehyde (mainly used as dispersing agents in dyestuffs

and as levelling agent and aftertreatment agent for fastness improvement) and in the majority of cases

fatty amine ethoxilates (mainly used in levelling agents).

The ethoxy chain in alkyl phenolethoxilates (APEO´s) is readily biodegradable but nonylphenol which

is the main intermediate compound during biodegradation shows a very low degree of biodegradation,

a high fish toxicity and reproductive toxicity [Schäfer, 1996]. Therefore TEGEWA (German

association of textile auxiliaries suppliers) and other German associations decided in 1986 to phase out

APEO´s in detergents [TEGEWA, 1986].

To minimise ecological load in wastewater caused by surfactants the following principles should be

regarded: - 189 -

are not released to wastewater).

303 A: DOC or COD degradation > 80%; mod. Zahn-Wellens test: DOC-elimination > 80% in 7

days) if effectiveness of products is comparable to common products. For the choice of the

products the ARS classification scheme (4.2.1.1.1) can be helpful.

concerning working place atmosphere.

Degree of biodegradation of wastewater increases. Fish toxicity of the wastewater is reduced.

There are manifold application fields for surfactants in textile finishing. Recipes and application

techniques are process specific. There is no general difference for the application of ecologically

optimised products. However if common surfactants are substituted by more environment-friendly

products the process reliability and possible differences in effectiveness of the products should be

regarded.

For textile finishing industries, the influence on the selection of surfactants is low if the products are

used only as additives in textile auxiliaries and dyestuffs and a declaration in the Health and Safety