Code SH (6 chiffres)
3913.10.••.••
Le code SH à 6 chiffres pour acide alginique est 3913.10.
Les 6 premiers chiffres sont identiques dans tous les pays du Système harmonisé ; le code national complet à 8-10 chiffres (ex. TARIC UE, HTSUS États-Unis) dépend du pays de destination.
Alginic acid, a poly(uronic acid), is extracted from brown algae (Phaeophyta) by maceration in an alkaline solution. It may be produced by precipitating the extract with a mineral acid or by treating the extract to obtain an impure calcium alginate which on treatment with a mineral acid is transformed into alginic acid of high purity. Alginic acid is insoluble in water but its ammonium and alkali metal salts dissolve readily in cold water to form viscous solutions. The property of forming viscous solutions varies with the origin and degree of purity of the alginates. Water-soluble alginates are used as thickeners, stabilisers, gelling and film-forming agents in, for example, the pharmaceutical, food, textile and paper industries. These products may contain preservatives (e.g., sodium benzoate) and be standardised by the addition of gelling agents (e.g., calcium salts), retarders (e.g., phosphates, citrates), accelerators (e.g., organic acids), and regulators (e.g., sucrose, urea). Any such additions should not render the product particularly suitable for specific use rather than for general use. Among the esters is propylene glycol alginate which is used in foodstuffs, etc