To provide lab data about which sealants
and tapes last, and which are likely
to fail, research was conducted at Lawrence
Berkeley National Laboratory Environmental
Energy Technologies Division. Their
major conclusion was that one should
not use duct tape to seal ducts (specialty
tapes are available for this purpose).
(They defined duct tape as any fabric-based
tape with rubber adhesive.) The testing
done shows that under challenging but
realistic conditions, duct tapes become
brittle and may fail.[6] Commonly duct
tape carries no safety certifications
such as UL or Proposition 65, which
means the tape may burn violently, producing
toxic smoke; it may cause ingestion
and contact toxicity; it can have irregular
mechanical strength; and its adhesive
may have low life expectancy. Its use
in ducts has been prohibited by the
state of California[7] and by building
codes in most other places in the U.S.
However, metalized and aluminum tapes
used by professionals are still often
called "duck/duct tapes".
