Table: air_filter_data
Columns: usage
class
performance
performance_test
particulate_size_approaching_100_retention
test_standard

Question: Which  Performance has a Test Standard of bs en779, and a Particulate size approaching 100% retention of >2µm, and a Class of f6?
SQL: SELECT "performance" FROM air_filter_data WHERE "test_standard" = 'bs en779' AND "particulate_size_approaching_100_retention" = '>2µm' AND "class" = 'f6'

Question: Which Performance has a Usage of hepa and a Class of h14?
SQL: SELECT "performance" FROM air_filter_data WHERE "usage" = 'hepa' AND "class" = 'h14'

Question: Which Particulate size approaching 100% retention has a Usage of semi hepa and a Class of h12?
SQL: SELECT "particulate_size_approaching_100_retention" FROM air_filter_data WHERE "usage" = 'semi hepa' AND "class" = 'h12'

Question: Which Test Standard has a Usage of secondary filters, and a Class of f5? Question 4
SQL: SELECT "test_standard" FROM air_filter_data WHERE "usage" = 'secondary filters' AND "class" = 'f5'

Question: Which Performance has a Performance test of average value, and a Class of f6?
SQL: SELECT "performance" FROM air_filter_data WHERE "performance_test" = 'average value' AND "class" = 'f6'

Question: Which Class has a Performance test of minimum value, and a Usage of semi hepa, and a Performance of 99.5%?
SQL: SELECT "class" FROM air_filter_data WHERE "performance_test" = 'minimum value' AND "usage" = 'semi hepa' AND "performance" = '99.5%'