Chemical Facility Security Improvement Act of 2011 - Prohibits federal funds from being used by the Secretary of Homeland Security (DHS) to approve a site security plan for a chemical facility unless the facility meets or exceeds security standards and requirements to protect it against terrorist acts established by the state or local government for the area where it is located.
Amends the Department of Homeland Security Appropriations Act, 2007 to: (1) repeal a provision prohibiting the Secretary from disapproving a site security plan based on the presence or absence of a particular security measure; (2) require vulnerability assessments and site security plans to be treated as sensitive security information; and (3) repeal a provision limiting to the Secretary any right of action against a chemical facility owner or operator to enforce security measures.