Acid & Alkali Resistant Fireproof Chemical Laboratory Ductless Bench

Basic Info.

Packaging & Delivery

Product Description

Product Description

Fume hoods should provide a safe and functional workstation for laboratory workers, and are often purchased with vented, flammable, or corrosive storage base cabinetry. Flammable (flash point < 100 °F) and combustible chemicals (flash point >100 °F) impose a fire hazard when stored/used improperly. The most common fume hood safety hazards that arise in laboratories stem from cluttered workstations, improper chemical storage, chemical fume hood incompatibility, and failure to check the hood flow indicator to make sure that it is working properly before starting work.
When choosing a ducted or ductless system, it is important to get all of the necessary components to maintain good lab practices. Cabinets are available for regular, solvent (flammable and combustible), and corrosive (acids or bases) storage. Some cabinets are designed without a bottom for easy access to equipment that can be rolled into and out of the cabinet. If storage is not necessary, simple base stands or carts (for portable hoods) are available to elevate and support the hood and work surface.
Work surfaces vary in composition, abrasion, chemical, and heat resistance. Solid epoxy resin work surfaces provide the highest-level resistance, allowing users to perform tasks with high concentrations of solvents, acids, and bases. Solid phenolic resin stations are intended for high chemical resistance, but are not as hard and durable as epoxy stations. Stations made of composite resin provide the least amount of chemical resistance and are intended for general use only. Stainless steel work surfaces are also available for perchloric acid and radioisotope fume hoods, both of which require ducted exhaust.
All work surfaces can be purchased with or without spill containment for extra protection, and with cutouts for cup or trough sinks. However, the more plumbing that a hood requires, the less feasible portability becomes. Sinks would likely be plumbed to acid waste systems, and if gas, compressed air, N2, or vacuum turrets are necessary, then disconnecting and reconnecting the unit to move it becomes more of a bother.

Ductless fume hoods provide a cost-effective and environmentally friendly alternative to traditional ducted fume hoods, but not all chemicals are appropriate to use in ductless systems. Since ductless hood filters have different affinities and adsorption rates for various chemicals, these hoods are fairly chemical-specific, depending on the filters employed, and are not optimal for applications involving high evaporation, viruses, bacteria, trace metals, perchloric acid, acid digestions, and radioisotopes. It is important to realize that chemicals trapped in the filter and vapors entering the filter may react and alter filter breakthrough and retention.
Perchloric, picric, and nitric acids are particularly dangerous, especially at higher temperatures, and should be used with extra precaution in ducted, stainless steel hoods. Perchloric (an oxidizing inorganic) and picric (an organic) acids require special handling altogether because they are very strong oxidizers at high temperatures, reacting with metals, wood, and other combustibles to form explosive compounds. Picric acid is also potentially dangerous when dry or contaminated because picrate metal salts are potentially explosive compounds. Organic solvents, sulfuric acid, and acetic acid should never be used in a perchloric acid hood. Acid digestion fume hoods provide a safe environment for heavy use of acids (other than perchloric and picric) at high temperatures.

What Is a Fume Hood?
A fume hood is a piece of laboratory equipment designed to minimize a person's exposure to hazardous chemicals. The fume hood draws away harmful vapors so lab employees can work with chemicals without the risk of accidental exposure. The air is extracted from the fume hood and filtered to remove dangerous vapors, and then either exhausted outside of the building or recirculated back into the lab.
How Does a Fume Hood Work?
The fume hood works by using a sash (a window that opens or closes to protect the user) to contain the vapor and keep it away from the user's face or to prevent it from drifting out into the rest of the laboratory. Blowers draw in air from the room, through a filter or number of filters within the fume hood and towards an exhaust area.
To safely work in a fume hood, keep all work at least six inches away from the plane of the sash. This will ensure fumes are pulled away from the user. Also, make sure the hood sash remains closed as much as possible and keep the hood slots and baffles free of any obstructions by containers or equipment. Never place your head inside the fume hood when working with chemicals.
The airflow will differ depending on the type of hood you use. For a constant air volume (CAV) hood, the fan has only one speed, providing a stable and continuous airflow. A variable air volume (VAV) hood allows users to adjust the velocity of the exhaust for added versatility, while reduced air volume (RAV) hoods offer lower airflow performance, making them ideal for working with less harmful compounds.