To shield workers from toxic fumes and to protect the specimen, labs are outfitted with laboratory fume hoods. This is mandatory lab safe equipment should be installed in labs that deal with chemical and toxic research and similar applications because this is used everyday.
To keep toxic fumes out of the lab’s working area and to protect the worker and specimen from these fumes, laboratory fume hoods are installed. These are partially enclosed work spaces that are ventilated and do the job of exhausting fumes outside of the lab area. It takes up a small space in a lab but has large usable interior working depth to allow the enough space to do experiments.
The tempered safety glass positioned at the back, and sides and tall viewing window give superior visibility for demonstrating chemical experiments or to observe how students or workers conduct the experiment. The unit has a hood of course and a sash that can be raised for easy loading and cleaning, and opened or closed to maximize or minimize access to airflow. Laminar Air Flow For the analysis of trace metals and corrosive substances, especially thermoplastic designed laboratory fume hoods that resist corrosion are recommended for installation.
The fume hood’s efficiency is measured by speed of the air flow that crosses between the work surface and the sash. This is measured in feet by the minute and the greater the velocity of the hood face, the faster toxins and vapors are flushed out. There is a recommended hood face velocity for the amount air necessary to achieve laminar flow velocity and that is 100 feet per minute.
Generally laboratory fume hoods prevent exposure to vapors and toxins and there are different hoods designed to work in different velocities for various chemical and technological applications. There are two types of hoods – radioisotope hood systems and perchloric acid systems. The first type is fashioned from stainless steel that prevents the absorption of radioactive elements. Perchloric acid hoods prevent the buildup of volatile perchlorate salts along the exhaust systems.
There are five standard construction types available to meet conventional, bypass, variable air volume, bypass, auxiliary, and ductless requirements. The conventional type facilitates a constant volume of exhausted air without regards to sash heights.
Bypass hood incorporates design that gives additional room air even when the sash is down or closed. The variable air volume hoods are technically sophisticated to keep air velocity constant whatever the sash height.
If energy savings is a factor, the auxiliary laboratory fume hood that supply outside air via the bypass hood thereby reducing the volume of exhausted air-conditioned or heated room air. This contains extra controls to adjust face velocity of air to match different sash positions. The ductless laboratory fume hoods are capable of re-circulating air back to the lab after filtration systems work. These hoods use higher HEPA filters to remove air contaminants.