Det er faktisk slik at spørsmålet ikke kan besvares med sikkerhet!
Grunnen til det er at det er så mange varierende faktorer som produsenten av glasuren ikke har kontroll på.
Den ferdige gjenstanden må gjerne vurderes som matsikker, men det er mange forskjellige årsaker som vi som leverandør ikke har kontroll på.
Ting som må tas hensyn til er:
Leiren Overflatestrukturen Brennkurven Oksidering Overføring av stoffer fra andre gjenstander i denne eller tidligere brenninger.
Glasurer med matte overflater, krakkeleringer eller andre ikke blanke glasurer bør unngås på bruksgjenstander da bakterier kan feste seg på gjenstanden.
Generelt vil en glasur som er angitt som matsikker være det så sant den er brent på en passende leire til riktig temperatur, men den eneste helt sikre metoden er å teste hver gjenstand i et sertifisert laboratorium.
Food Safe or Dinnerware Safe Glazes
The phrase, "Food Safe" refers to the fired finish of glazed pottery.
"Food Safe", glazes will pass the "Metal Release Test" for Lead and Cadmium. These are the only two elements tested for in the metal release test for Food Safety.
Leadless or Lead-free glazes which do not contain any Lead or Cadmium can be designated as Food Safe Glaze.
Cadmium containing stains were typically used to produce bright red colours in glazes, these OLD GLAZES will not pass the test. However, in the last few years a specially prepared Zircon encapsulated Cadmium Red glaze stain has been developed and NEW glazes containing these new stains will pass the metal release test limits for Cadmium, so these bright coloured reds available now can also be considered Food Safe.
Potterycrafts produces a wide range of food safe glazes. We do not need to carry out specific tests on each glaze to determine if the glaze can be considered Food Safe because the MSDS sheet provides us with details of any hazardous substances in the glaze recipe. Section 3, Composition, which declares any hazardous substances and their approximate quantity plus their Hazardous Phrases.
All Potterycrafts Leadless Earthenware glazes even the bright coloured reds & yellows which contain the Zircon encapsulated Cadmium colours are "Food Safe".
It is also worth considering the surface finish of glazes. When the surface finish is very rough, food particles can become caught in the surface. These glazes finishes are "Food Safe", However a rough surface finish may not be hygienic. Also, some of the metallic effect glazes such has Fools Gold, Bronze and Pewter are Lead and Cadmium free so technically could be considered "Food Safe". However, because the metallic surface effect is only microscopically thick the durability of the metallic effect is very poor and it is easily eroded especially if in contact with acidic fruit juices.
Har du spørsmål angående produkter eller tjenester? Kontakt oss gjerne for en uforpliktende prat.