Radon Testing for Safe Schools Act of 1991 - Amends the Toxic Substances Control Act to direct the Administrator of the Environmental Protection Agency (EPA) to publish guidelines on testing for and remediating radon in school buildings. Requires local educational agencies located in areas designated as priority radon areas to conduct radon tests in school buildings owned or operated by such agencies. Directs the Administrator to designate such areas by September 30, 1991. Makes test results available for public review.

Requires individuals testing for radon to be approved by the Administrator or a State pursuant to a radon proficiency program.

Authorizes appropriations for: (1) the Administrator to implement radon remediation measures for local educational agencies; and (2) grant assistance for implementing such measures and for conducting additional radon tests.