Lexicon: P
Parabens
Abbreviation for 4-hydroxybenzoic acid ester. Preservatives and fungicides authorised for food and pharmaceuticals.
Only have a reliable bactericidal effect in very high concentrations (~ 1 g/l). In dilution (i.e. after addition to the aquarium) they are degraded by bacteria.
Although the longer-chain esters are more effective, they are much less soluble in water.