Which Class has a Performance test of minimum value, and a Usage of semi hepa, and a Performance of 99.5%?
CREATE TABLE "filter_classes" (
  "usage" text,
  "class" text,
  "performance" text,
  "performance_test" text,
  "particulate_size_approaching_100pct_retention" text,
  "test_standard" text
);
SELECT "class" FROM "filter_classes" WHERE "performance_test"='minimum value' AND "usage"='semi hepa' AND "performance"='99.5%';