When your application uses request attributes on a per request basis and you do not want that particular attribute to be managed in the Bridge Request Scope, you must use the following configuration in your faces-config.xml to have them excluded.

<application>
  <application-extension>
    <bridge:excluded-attributes>
      <bridge:excluded-attribute>foo.bar</bridge:excluded-attribute>
      <bridge:excluded-attribute>foo.baz.*</bridge:excluded-attribute>
    </bridge:excluded-attributes>
  </application-extension>
</application>

Above you will see that any attribute namespaced as foo.bar or any attribute beginning with foo.baz. will be excluded from the Bridge Request Scope and only be used per that application's request.