When choosing a fume hood, you need to consider factors such as the amount of exhaust power, the materials used to make it, and the regulations that govern it. Listed below are some tips to help you select a fume hood that meets your needs. This will ensure the safe use of the fume hood for your workplace.
Face velocity is a measurement of exhaust power
Face velocity refers to the average speed of air entering the fume hood’s face opening. It is commonly expressed in feet per minute (fpm) but can vary from state to state. In addition to determining the safety of fume hoods, face velocity is a key component of the performance of fume hoods.
When it comes to fume hoods, the face velocity of the exhaust will be a good indicator of the efficiency of the machine. A machine with low face velocity will be inefficient and allow chemical fumes to escape, while one with high face velocity will waste a lot of conditioned air. Moreover, excessive face velocity can be hazardous to those working around the machine.
Choosing the proper face velocity for fume hoods is an important consideration in laboratory settings, where face velocity must be under 100 fpm. Using this criterion may not ensure the total containment of fumes, however. Several other factors must be taken into consideration as well.
Materials used in a fume hood
The fume hood’s lining should be made from materials that are corrosion resistant and non-combustible. The surface of the hood should also have rounded corners. In addition, it should have a low flame spread index. According to NFPA method 255, the flame spread index of building materials should be 25 or less.
It is necessary to check the air flow through the fume hood regularly. It can be done by placing a piece of paper close to the bottom of the sash. If the air flow is insufficient, the fume hood should not be used until it is repaired or certified. It should be noted that fume hoods should never be used with perchloric acid or any other material that can corrode the sash. These substances can accumulate explosive perchlorate salts in the exhaust system.
In addition to sashes, fume hoods may also include ductwork. This is important for labs that use hydrofluoric acid, and the hood should be resistant to the acid. For this reason, HF hoods feature lexantm Sashes that are fog-proof. Some fume hoods also have an inactive setback mode, which minimizes the air flow during inactive use. The hood’s inactive setback mode is activated by a motion sensor that is placed over the hood. If there is no movement within the hood for two minutes, the fume hood goes into inactive mode.
The functions of fume hoods must be effective in reducing or eliminating airborne harmful gases. A fume hood should have a ventilation fan connected by a single pipe for best effectiveness. Multiple piping is suitable only for rooms or floors separated by walls. To make sure the ventilation fan works well, it must be located at the end of the pipeline.
The fume hood’s size and design are determined by the materials that will be tested in it. Some of these materials will have different suction speed requirements. Other factors to consider include the material of the surface and fixture. Your budget will also play an important role in your decision.
To avoid exposure to fumes, use proper fume extraction equipment. These equipments must meet industry standards, as well as government regulations. Learn more about these regulations by watching a webinar offered by RoboVent. In addition to using proper equipment, you should also use good housekeeping practices in the laboratory.
In addition, you should record all monitoring results. This will help you to track the risks and control them accordingly. You should also keep the monitoring results accessible for employees to review. You should also limit the time workers spend close to the dust. This means using automatic feed and take-off devices, as well as wearing protective clothing appropriate to the conditions of handling.
Regulations for fumes also require the use of proper ventilation. These fumes are very toxic and can cause respiratory problems. OSHA recommends that employers install exhaust ventilation and monitoring equipment. These measures should reduce the risk of occupational asthma.
Exposure to welding fume can have acute and chronic health effects. The most common adverse health effect is occupational lung disease, but there are also risks to eyes, skin, and confined spaces. Acute effects occur shortly after exposure, while chronic effects occur over time and can lead to more serious diseases. The HSE estimates that forty to fifty welders are admitted to hospital every year due to the effects of welding fume.
The Allied Pilots Association, a union that represents airline crews, estimates that there are as many as 20,000 fume incidents every year, or five each day. However, there is no standardized protocol for recording these events, so it is difficult to gather consistent data. While the causes and effects of fume events are still unclear, the worst possible scenarios involve a combination of fumes and low levels of oxygen.