Polyurethane safe?

[Liquidplants]

Hello, i was wondering if polyurethane is safe for fresh water aquariums?
i wanted to polyurethane obscure rocks that i don't know their composition before i introduce them into a tank.
WIKI-

Fully reacted polyurethane polymer, CAS # 9009-54-5 (CAS registry number), is chemically inert.[24] Foams In the United States, no exposure limits have been established by OSHA (Occupational Safety and Health Administration) or ACGIH (American Conference of Governmental Industrial Hygienists). It is not regulated by OSHA for carcinogenicity.

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looks safe =] please am i going crazy

~LiquiD~

 

[Liquidplants]

bump for an answer =]

 

[Liquidplants]

Anyone???

 

[dr_sudz]

pour an acid over the rocks, this will let you know if they are calcium based or not because if they are they will fizz if not they are safe for your aquarium and won't effect the pH. The urethane I would most be most worried about seeing that most of that stuff is not usually made for full water use.

 

[Liquidplants]

thanks, that does make sense. will lemon juice be enough of an acid?

Grats on your 2,000th post =]
~LiquiD~

 

[bob965]

I wouldn't expect the polyurethane to hold up to full immersion over time. If you really want to coat the rocks, use epoxy resin.