What is laminar hood?

A laminar flow cabinet or tissue culture hood is a carefully enclosed bench designed to prevent contamination of semiconductor wafers, biological samples, or any particle sensitive materials. Air is drawn through a HEPA filter and blown in a very smooth, laminar flow towards the user.

What is laminar hood used for?

Laminar flow hoods are ventilation devices used within the lab to provide an aseptic work area that helps protect both the laboratory personnel and the materials they are working with. Hoods are classified as either Class I, II, or III depending on the level of protection they offer.

How does a laminar flow hood work?

A laminar flow hood consists of a filter pad, a fan and a HEPA (High Efficiency Particulates Air) filter. The fan sucks the air through the filter pad where dust is trapped. After that the prefiltered air has to pass the HEPA filter where contaminating fungi, bacteria, dust etc are removed.

What is a laminar fume hood?

A laminar flow hood is defined as; an enclosed workbench used to create a contamination-free work environment through installed HEPA filters that capture all the particles entering the cabinet. A laminar flow hood is for working with substances that are not hazardous to the health of personnel.

Which hoods are sometimes called laminar hoods?

Many research and animal laboratories use containment devices to keep the user separated from the hazards they are working with. These devices are often referred to by many different names including cell culture hood, tissue culture hood, laminar flow hood, PCR hood, clean bench, or biosafety cabinet.

What is HEPA filter in laminar air flow?

In a laminar flow hood the air is passed through a HEPA (High Efficiency Particulates Air) filter which removes all airborne contamination to maintain sterile conditions.

What is the difference between a fume hood and a biosafety cabinet?

A chemical fume hood protects the user while a biosafety cabinet protects the user, the environment, and the material. Biosafety cabinets have high-efficiency particulate air (HEPA) filters while chemical fume hoods do not.

Why do we use fume hood?

Fume Hood Purpose and Importance



The purpose of a chemical fume hood is to prevent the release of hazardous substances into the general laboratory space by controlling and then exhausting hazardous and/or odorous chemicals.

Can I use a biosafety cabinet as a fume hood?

While a biological safety cabinet (biosafety cabinet or BSC) is sometimes referred to as a ductless fume hood, the BSC does not protect from chemical vapors. Likewise, ductless fume hoods are not biological safety cabinets, but can protect from particulates when fitted with HEPA/ULPA filters.

When would you use a fume hood?

Fume hoods should be used when working with toxic compounds or compounds with a boiling point below 120°C. Fume hoods, or other effective local ventilation, must be provided and used when the materials used will exceed exposure limits in the laboratory.

How effective is a fume hood?

No matter how well a fume hood is designed, it won’t be effective unless proper laboratory safety measures are taken.

What chemicals require a fume hood?

Applications. Fume hoods: Chemical fume hoods can be used to handle the following: odorous materials, toxic gases, reactive materials, chemicals that can spatter, aerosols, carcinogens, flammables or other toxic and volatile materials.

What is sash height?

Share. A biosafety cabinet’s “sash height” refers to the level a safety cabinet window is raised. Only when the sash height is set appropriately, will the safety cabinet properly protect against contamination.

What is a ductless fume hood?

Ductless fume hoods, sometimes called carbon-filtered enclosures or filtered fume hoods, are self-contained, filtered laboratory enclosures that remove hazardous fumes, vapors and particles from the laboratory. Unlike traditional fume hoods, installation costs are very low and no ductwork is required.

Can you store chemicals in a fume hood?

The fume hood is often the primary control device for protecting laboratory workers when working with flammable and/or toxic chemicals. Do not permanently store any chemicals inside the hood.

Will the glass in the sash protect me from explosions?

14. Will the glass in the sash protect me from explosions? The sash will protect you from some explosions and fires, for that reason you should keep it as low as possible. But if you are working with reactive substances or with pressurized equipment, you should keep your work behind a portable blast shield.

How often do fume hoods need to be inspected?

For fume hoods, they are primarily concerned with airflow at the face of the hood, monitoring, maintenance, and exhaust. OSHA indicates that the quality and quantity of ventilation should be inspected at installation, then regularly monitored at least every three months.

Can fume hoods be turned off?

Fume hoods shall not have an on/off control accessible in the laboratory, unless the lab has an alternate exhaust ventilation system or the exhaust is being filtered through a charcoal or HEPA filter. Fume hoods are an integral part of the entire laboratory’s air balancing system which must be maintained.

Should fume hood be closed when not in use?

All portable chemical containers must be removed from the hood when not being used and at the end of the working day. Caps on the bottles of chemicals being used in the fume hood should be tightly closed when not in use. Substitute with less hazardous or less volatile chemicals where possible.

How do you test a fume hood?

Process:

1. Turn on hood.
2. Check the vaneometer. …
3. Match red arrow on sash with red arrow on the side panel of the hood.
4. To acquire reading hold vaneometer in the center of the hood.
5. Acceptable standard -Chemical fume hoods should operate at a face velocity of (80-120) Linear Feet Per Minute.

Where does fume hood vent?

the atmosphere

A fume hood is a ventilated enclosure in which gases, vapors and fumes are contained. An exhaust fan situated on the top of the laboratory building pulls air and airborne contaminants through connected ductwork and exhausts them to the atmosphere.

Do fume hoods filter air?

Air is then filtered and/or treated by the building’s exhaust system before exiting the facility (ducted) or by filters contained in the fume hoods, which clean the contaminated air and recirculate it directly back into the laboratory (ductless).

How does a hood work?

Quote from video:The air is circulated through the vent hood by a fan motor. Which is energized by voltage sent to the motor. When the fan switch is actuated.

Is fume hood an equipment?

A fume hood is typically a large piece of equipment enclosing five sides of a work area, the bottom of which is most commonly located at a standing work height. Two main types exist, ducted and recirculating (ductless).

Who invented fume hood?

Thomas Jefferson

The First Fume Hood



At the University of Virginia during the 1800’s, Thomas Jefferson did just that. He constructed a hearth with a sand bottom and special flues to vent toxic gases. Years later, Thomas Edison mimicked Jefferson and came up with what is believed to be the first fume hood.

Why are alcohols kept in the hood?

Handle alcohols in a fume hood to capture and prevent any flammable and/or combustible concentrations of vapors from reaching any source of ignition.