From HR 669 ...

SEC. 2. PURPOSE.
The purpose of this Act is to establish a risk assessment process to prevent the introduction into, and establishment in, the United States of nonnative wildlife species that will cause or are likely to cause economic or environmental harm or harm to other animal species’ health or human health.

You can read HR 669 here ...

http://frwebgate.access.gpo.gov/cgi-...h669ih.txt.pdf

-adam