Lab Furniture Acid Alkali Resistance Fume Hood with Water Sink

The main purpose of installing a fume hood in a laboratory is safety. It's that simple. The better the fume hood, the safer the employee and when it comes to toxic chemicals and tracer gases, you can't be too careful. Because the safety standard is so high for labs, it's not only critical to have your fume hood testing annually, it's also illegal not to. 
There are three things that the tester is checking when performing a fume hood safety inspection: flow visualization, face velocity, and tracer gas performance. The measuring scale is broken down into four ratings which are "fail, poor, fair and good" and of course the aim of the test is for the fume hood to rate "good" which ensures lab safety and compliance.

Acid digestion is one of the more common procedures performed in fume hoods that causes premature rusting and corrosion. All-metal fume hoods, standard in most labs, will rust over time and need to be replaced, but specialty labs working with acids to break down organic and inorganic materials often make the mistake of not using metal-free fume hoods. Hydrochloric acid, sulfuric acid, hydrofluoric acid and nitric acid are common in any digestion experimentation and analysis, all of which will immediately rust and corrode any exposed metal it touches, resulting in contamination to samples.

The fume hood is an important safety staple in chemistry classrooms and research labs. Getting the most out of a fume hood begins with selecting the right one for your application. That means knowing precisely what type of work will be performed in the fume hood and making the choice between constant air volume and variable air volume, choosing between a ducted and a ductless fume hood, and selecting the appropriate material of construction.

Labs are a risky environment. Between the sharp objects and beakers lined up in rows, workers have to constantly be aware of their surroundings. Personal protective equipment and other controls are part of what keep them safe, and fume hoods are no exception.

Fume hoods are an engineering control in labs, meaning they control the hazard. When scientists are working with dangerous materials that emit hazardous vapors, gas, and dust, a fume hood will move it away from their faces and out of the area through an exhaust system.

Without getting too deep into the weeds about the inner workings of the mechanism, it's essential that they are always in working order. Professionals should thoroughly inspect and document fume hoods on an annual basis. A quick visual inspection should be done every time it's used. If there is any suspicion that a fume hood is not working correctly, it's imperative to get in touch with someone ASAP.

No air flow. A quick way to check to see if there's air movement is to tape a piece of tissue to the sash. Turn on the hood. A tissue "flapping in the wind" is indicative of ample air movement - good news.

Weird noises. Occasionally, the fan or motor will need some TLC. Unusual noises are are good indicators to shut the hood down until it can be serviced.
Immediately tag the fume hood as "DO NOT USE" and contact the responsible party to get it repaired if any red flags arise.

Flow visualization consists of two tests known as local smoke and gross smoke. These names are self-explanatory in that the tester utilizes smoke to check for leaks, or cracks in the fume hood, structural defects, air flow inefficiency or other issues that may allow gas to escape. A smoke gun is used to perform this test but the gross smoke measurement is done on a macro level in which a smoke bomb is detonated in the middle of the fume hood. If any smoke escapes out of the front of the hood during either test, the fume hood will receive a "fail" rating and appropriate action must be taken to rectify it.

Face velocity is the measurement of air flow through the fume hood. Different fume hoods have face velocity specifications for ventilating gases and it's important that the fume hood maintain these levels. Otherwise, it's considered compromised and unsafe. This test is performed with the sash open 25%, 50% and 100% using a device that measures air flow at different place within the hood. Those readings are then compared to the manufacturer's specifications for that fume hood to ensure complete functionality.