I am not surprised you had difficulty finding answers to your questions. Most
manufacturers are quite proprietary about their manufacturing processes and morespecifically finishing processes.
Cast iron, fiberglass, acrylic, Vikrell
Cast iron tubs with enamel finishes are unlikely to contain lead unless theyare old, were re-finished prior to the lead paint ban or are manufactured in China. (Not allChinese made tubs have lead in them but you should be cautious).
I am not a chemist but I do know that fiberglass, acrylic, or "Vikrell", are made froma variety of components including poly resins and plasticizers which contain phthalicacid or phthalic esters which phthalates are derived from as well as BPAs. The US isfollowing the lead of Europe and Canada and phthalates are being phased out of usein consumer products while BPAs have been banned outright from specific consumerproducts with likely more to come.
Risk of leaching
It is difficult to say if there is any potential leaching risk from these materials which canbe directly linked to health risks with bathtub use.
From a purely structural standpoint,the gelcoat surface of tubs and shower surrounds are highly non-porous (acrylic moreso than fiberglass or Vikrell) which should effectively seal in the chemicals of concern.
- That said, improper use or maintenance of the tub or shower surround along withprolonged exposure to the sun can degrade the surface layer the tub/shower potentiallyreleasing the phthalates or BPAs.
- With respect to the gelcoat itself, this material isdesigned to be UV resistant and is relatively inert once cured so again leaching shouldbe minimal but the fact is that it too is made from epoxy or polyester resin which maycontain phthalates or BPAs.
Making a decision
In conclusion, it is difficult to say definitively that any one material is safer than another.
- I can say that acrylic is more durable than fiberglass or Vikrell and that enamel is moredurable than acrylic.
- There are many factors that go into a product decision selection.
- Heath risks appear to be your primary criteria.
When making a product decision,also consider the cost, the manufacturing process (does it release pollutants into theatmosphere), the lifecycle of a product as well as its carbon footprint.
For more information:
Read "Are there non- or less-toxic bathtubs?" a Q&A answered by Karen Smuland.