Why is it important to never leave an experiment unattended?
Equipment and experiments that run unattended during the day and overnight have the potential of causing significant problems and harm to University personnel, facilities, and equipment.
What is the wafting technique?
Wafting is a technique of using your hand to draw air over the opening of a container in the direction of your nose. Air mixed with the substance is drawn into your nose so that the smell from the original substances is diluted.
Why should you never eat or drink in the lab?
You should not eat in a chemistry lab because of the threat of contamination. This threat of contamination has two parts. The first part is that you never know where chemical residue may be and ingesting it could be dangerous. While you are eating you may leave crumbs or residues on the lab surfaces.
What is the purpose of a fume hood?
Chemical fume hoods, when used properly, are one of the most reliable engineering controls in the laboratory. They protect workers by: Containing vapors, dusts, gases, and fumes generated within the hood, and removing them as air flows into the hood and then out via the laboratory exhaust system.
How do I know if my fume hood is working?
Measure velocity of air flow into laboratory fume hoods using a Vaneometer. The purpose is to re-confirm function of fume hood at time of use. A piece of tissue paper or kimwipe may be used to roughly check the flow. If the tissue is not being pulled into the fume hoods, call 3703 or 3663 immediately.
Can you store chemicals in a fume hood?
One of the things we find frequently when performing lab safety audits is chemicals (and other items) stored in the fume hoods. In case there is a spark or electrical malfunction in the hood, flammable or reactive chemicals could cause hazardous reactions in the hood.
Can you use flammable chemicals in a fume hood?
The lights installed inside fume hoods are sealed to keep flammable vapors away, these lights are called “intrinsically safe.” All electrical components in new fume hoods are intrinsically safe so flammable vapors should not be a fire hazard.
When working with chemicals inside a fume hood you should?
Safe Fume Hood Work Practices
- Conduct all work and keep all apparatus at least 6 inches back from the face of the hood.
- Keep the hood sash closed as much as possible.
- Keep the hood slots and baffles free of obstruction by apparatus or containers.
- Do not permanently store apparatus or chemicals in the hood.
How should a fume hood be left when not in use?
Fume hoods are designed so that when they are not in use the sash should be shut. There is an airfoil sill at the bottom of the sash in all modern fume hoods so that even when the sash is shut, air will still be pulled from the room to exhaust any hazardous vapors.
Do I need an explosion proof fume hood?
All wiring must be done in the field per local code. So if the local fire codes require an explosion-proof hood, or if the room itself is rated* such that the atmosphere of the room has a high concentration of flammable vapors or particulates, then the hood will need to be explosion proof.
Where do fume hoods vent to?
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.
How do you check fume hood face velocity?
Assessing face velocity results
- Check airflow velocity meter type.
- If possible, verify readings with another air velocity meter or by checking air volume using a pitot tube traverse of the exhaust duct.
- Supply voltage is correct.
- Exhaust unit inlet and outlet conditions are suitable.
What should I look for when buying a fume hood?
There are two main factors to consider when selecting a fume hood style. First is the type of work being performed in the hood. Second is the air consumption of the hood. The types of fume hoods are airfoil by-pass, airfoil variable volume, airfoil add air, low flow, and other specialty fume hoods.
What are the key factors that will affect the effectiveness of a fume cupboard?
5 factors affecting your fume hood performance
- Fume hood design: Fume hood is meant for smooth exhaust of the flow without any reverse flow towards the user.
- Supply air: Lab supply air should be lesser than exhaust air to keep labs under negative pressure.
- Exhaust system:
- Exhaust stack design:
- User work practices:
How high should you keep the fume hood sash while using it?
sixteen inches
What is fume hood face velocity?
Face Velocity is a measurement of the speed at which air enters a fume hood’s face opening. These standards are intended to measure the ability of a fume hood to contain fumes and are based on the speed at which air enters a fume hood’s face opening.
What are fume hoods made of?
Acid digestion fume hoods have special liners manufactured of acid resistant materials such as unplasticized PVC. For acid digestion applications involving high service temperatures, other materials such as PVDF may be used. Sashes may be made of polycarbonate to resist hydrofluoric acid etching.
How much does a fume hood cost?
How Much Does A Fume Hood Cost?
| Fume Hood Size | Low Price Average | High Price Average |
|---|---|---|
| 4′ Fume Hood | $5,263 | $24,602 |
| 6′ Fume Hood | $7,979 | $56,809 |
| 8′ Fume Hood | $9,966 | $66,383 |
Do fume hoods filter air?
Ductless fume hoods are self-contained enclosures that filter air before returning it to the work environment.
What kind of chemical is used in a fume hood?
Perchloric Acid Fume Hoods
What is a fume hood sash?
A fume hood sash is a glass door located at the front of the fume hood that opens and closes, serving as a doorway to the workstation. The sash is an important safety component, offering protection and containment from dangerous chemicals and other materials.
Do ductless fume hoods work?
J. Ductless fume hoods offer many advantages over conventional ducted enclosures such as mobility, no installation costs and energy savings. However, they are only suitable primarily for lighter or fixed chemical applications.
What is the difference between laminar flow and fume hood?
In fume hoods and laminar flow cabinets, hazards or contaminants are reduced using airflow. Fume hoods draw in air across a workspace to remove hazardous fumes and fine particles, while laminar flow cabinets blow air through a filter and out to prevent contamination of samples by dust or biological materials.
How does a fume cupboard work?
For the purposes of this CoP, a fume cupboard consists of an enclosed compartment with a sash at the front, a current of air is pulled through the front of the opening, across the experiment and away from the user to prevent the inhalation of hazardous materials.
What features does a fume cupboard have?
The important design features for a fume cupboard of a box-like structure are tapered inlet, sash, baffle, working chamber and sash handle. They influence the ability of fume cupboard to contain and exhaust the hazardous chemicals. The performance of fume cupboard is primarily characterized by its airflow.