EDTA was and is still preferred because it is a good complex-builder. The main area where it is used is in soaps But EDTA as well as its replacement material, editronic acid, are nevertheless thought to be toxic and in addition not very biodegradable. A natural alternative is phytinic acid. It is derived from rice hulls and has become an additive in a number of products.

Biodegradability and toxicology EDTA and its metal complexes are not or only poorly biodegradable in wastewater treatment. By increasing the pH-value and prolonging the sludge age, however, an extensive biological elimination of EDTA can be achieved. A large number of microorganisms have been isolated from sewage sludge, sediments and soils, which can grow with EDTA as their sole source of C and N. The metal complexes of EDTA are not or only very little toxic for organisms. However, EDTA is also able to dissolve heavy metal salts that are difficult to dissolve from the sediments. When EDTA decays, these are released at the surface. The toxicity of EDTA to humans is also very low, so EDTA is approved as a food additive. In very high concentrations, especially free EDTA can lead to disorders by binding vital metals. The concentrations of EDTA measured in the environment are not harmful to humans. Environmental behaviour EDTA reaches the environment almost exclusively via wastewater. Since EDTA is degraded very slowly under normal conditions, it can be detected in low concentrations in practically all water samples. EDTA concentrations in rivers are between 10 and 100 µg/l, in lakes between 1 and 10 µg/l. In groundwater and bank filtrate EDTA can be found in concentrations between 1 and 100 µg/l. At neutral pH values, the adsorption of EDTA on mineral surfaces is low, which leads to a high mobility in groundwater. Only the FeIII-EDTA-complex is degraded very quickly by sunlight. This is the most important elimination process for EDTA in the environment. EDTA is only incompletely removed during ozonation or chlorination of drinking water. Today, EDTA is considered ecologically questionable, as free complexing agents dissolve heavy metals from the sediment and make them bioavailable. The Federal Environment Agency recommends "In the interests of a precautionary substance policy, EDTA and also other complexing agents that are difficult to degrade, such as diethylenetriaminepentaacetic acid (DTPA) or propylenediaminetetraacetic acid (PDTA), should be replaced by substances that are as easily degradable as possible and can thus be removed in sewage treatment plants". Possible substitutes are nitrilotriacetic acid (NTA) and its sodium salts, citrates, gluconates, alaninediacetic acid sodium salt (ADA), methylglycinediacetic acid (MGDA), etc. [8].