On a worldwide basis there are a number of testing standards. Each company that sells hoods will tell you that their hoods performs well accordingly to ASHRAE 110 or EN 14175 or some other test standard. But the reality is that these tests are usually done in test labs with near perfect conditions. So, this test is just confirming that the fume hood is well designed, but that is not an indication of how that hood will perform in your lab. Each lab is different as is each Laboratory Ventilation System.
But your lab is different. Laboratory ventilation systems are very complex and dynamic. The conditions are changing all the time. What you are actually testing is not just the hood, but how the hood performs in your lab. Studies on a global basis show that when testing installed fume hoods are tested, that 50% to 70% are not functioning safely.
That means that hood is losing containment and allowing fugitive contaminates to escape into the lab. This pollutes the air and makes it unhealthy for the occupants.
But it is not just the users that suffer, these pollutants damage lab equipment and can even corrupt the tests being performed.
The only way to know that your fume hoods are safe is to test them.