Acid and Alkali Resistant Polypropylene Heat Resistant Laboratory Chemical Duct Fume Hood Explosion Proof

In laboratories, fume cupboards are the primary method of controlling exposure to toxic, offensive or flammable vapours, gases and aerosols. A type of local exhaust ventilation system, fume cupboards typically consist of a cabinet, or hood, with a moveable front sash or window, made out of safety glass.

They rely on extraction, which is sometimes controlled by the building's air conditioning and heating system; fumes are drawn into the hood and expelled through a neutralisation filter. In order to keep protection levels high, fume cupboards have to be used effectively and maintained appropriately. Therefore, the airflow within the fume cupboard needs to be enough to control the airborne contaminants effectively, with factors such as design, size of the window opening, type of process and the substance(s) being controlled all affecting the airflow of the cupboard.

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.

When installing the fume cupboard, avoid placing it next to any windows, doors and walkways, as these can interfere with the ventilation system. Doing so will help to stop airborne contaminants from spreading around the laboratory.

It is vital that fume cupboards are used only for experimental work. A fume cupboard should never be used as a storage cupboard for pieces of science equipment; filling the cupboard can compromise the airflow and increase the chances of harmful substances leaking into the laboratory. The presence of stored chemicals in the cupboard could also increase the chance of further damage if an accident were to occur.

Likewise, it is important to avoid unnecessary clutter such as safety screens, ovens and trays. Again, this will cause turbulence in the air drawn across the base of the cupboard. The effect of turbulence can be reduced by raising all large objects off the base of the cupboard by placing them on blocks. As a rough guide, all pieces of equipment should be placed at least 150mm from the front of the glass.

When doing work in the fume cupboard, take care to ensure that all materials are kept inside the hood at least 150mm from the window opening. The sash opening must be as small as possible to minimise the chance of any fumes escaping. When not in use, always remember to close the sash. When you're finished, remove the chemicals and store them safely away from the fume hood.