Safety Guidelines for Undergraduate Electrical Labs
The power levels and the rotating machines used in Electrical Labs can pose significant hazard to the laboratory users, if not handled properly. The major hazards associated with electricity are electrical shock and fire. Electrical shock occurs when the body becomes part of the electric circuit. In addition to the electrical shock hazards, sparks from electrical equipment can serve as an ignition source for flammable or explosive vapors. Some general guidelines that can be used to reduce the risk of injury caused by laboratory hazards are as follows:
- Avoid contact with energized electrical circuits.
- Disconnect the power source before servicing or repairing electrical equipment.
- When it is necessary to handle equipment that is plugged in, be sure hands are dry and, when possible, wear nonconductive gloves and shoes with insulated soles.
- If it is not unsafe to do so, work with only one hand, keeping the other hand at your side or in your pocket, away from all conductive material. This precaution reduces the likelihood of accidents that result in current passing through the chest cavity.
- If water or a chemical is spilled onto equipment, shut off power at the main switch or circuit breaker and unplug the equipment.
- If an individual comes in contact with a live electrical conductor, do not touch the equipment, cord or person. Disconnect the power source from the circuit breaker or pull out the plug using a leather belt.
- Do not make circuit changes or perform any wiring when power is on.
- Do not wear loose-fitting clothing or jewelry in the lab. Rings and necklaces are usual excellent conductors in contact with your skin.
- It is wise in electrical labs to wear pants rather than shorts or skirts. Ties are also dangerous.
- Powered equipment can be hot! Use caution when handling equipment after it has been operating.
- Do your wiring, setup, and a careful circuit checkout before applying power.
- Use wires of appropriate length. Do not allow them to drape over your equipment. Avoid splices, which create live surfaces. When running a pair of wires to adjacent terminals, twist the wires together so they don’t dangle. This also neatens your work and will save time.
- Do not touch anything if your hands are wet. The "one-hand" approach is safest.
- If you can't keep your hand in your pocket, do not touch any metal object with free hand.
- Do not pull wires out until you are absolutely sure that the circuit is completely dead. Shocks can occur if an inductive load (motor or transformer) is disconnected while conducting.
- All the electrical equipment must be connected to the proper earth line.
- All high voltage equipment must properly be marked and danger signs displayed.
- Don't depend on switches to de-energize a circuit. Pull the plug out from the socket/outlet.
- If you are working on high voltage circuits, have a co-worker along with you who knows how to break the circuit to get you free and how to give you mouth-to-mouth resuscitation and closed chest heart massage.
- When you are mentally or physically tired, avoid work on energized circuits.
- High voltage connections must have no sharp points.
- Permanent or temporary enclosures around high voltage equipment should be used.
Safety Guidelines for DIBSD Laboratory
- You are required to wear protective head, foot, and body coverings to reduce particulate contamination.
- You must wear the required Personal protective equipment (PPE) to protect you from the materials and processes that you use.
- Eye protection such as safety goggles and glasses protect sight in the case of a chemical splash or uncontrolled reaction.
- Use the appropriate gloves for the chemicals you handle in order to protect your skin.
- Be familiar with the lab protocols and layout at your facility.
- DON’T use equipment, materials, or processes that you are unfamiliar with; get the proper training first.
- Locate and understand the proper operation of safety equipment including fire extinguishers, safety showers, eye wash stations, and emergency shut off and bypass switches.
- Know the facility emergency signals, alarms, and evacuation routes and procedures. Know and follow compressed gas cylinder safety protocols; ensure that you are familiar with hazardous gas monitoring equipment and the associated alarms.
- Chemical handling, including acids, bases, solvents, carcinogens, and cryogenics, is common in wet labs. Read and understand the material safety data sheets (MSDS) for the chemicals in the DIBSD lab to provide guidance on use, required PPE, spill procedures and disposal. If you are splashed with a chemical, immediately flush the area with copious quantities of water for 10 to 15 minutes and remove contaminated clothing.
- Pay special attention to the use of hydrofluoric acid (HF) because skin or eye contact is extremely dangerous. HF exposures may not cause pain at first, but the fluoride ion continues to burn through your tissue until it causes painful bone destruction. Rinse any suspected skin or eye contact immediately with water, and seek immediate medical attention. Calcium gluconate gel or other treatment methods may be needed, and these should be administered by a qualified medical professional.
- Always conduct chemical processes under fume hoods or in designated wet benches, if possible.
- Practice good housekeeping with chemicals: clearly label containers, minimize quantities, and clean up materials after use. Ensure that chemicals are stored in rated chemical cabinets and are separated by hazard class. Know the spill procedures and the location of spill equipment in the cleanroom. Properly dispose of all chemicals, mixtures, and spill cleanup materials as hazardous waste in designated waste streams.
Safety Guidelines for Molecular/Nanoelectronics Research Group (PG-20)
The chemicals and power levels used in MNRG Laboratory can pose significant hazard to the laboratory user if not handled carefully & properly. The major hazards associated with electricity are electric shock & fire. Some General guidelines that can be used to reduce the risk of injury caused by laboratory hazards are as follows:
- Know all the safety rules and procedures that apply to your work. If you don’t understand ask someone.
- Avoid working alone in the laboratory.
- Do not eat, drink or smoke in laboratory.
- Always read Material Safety Data Sheet for chemicals before using them in order to know safety precautions for it.
- Always wear gloves, laboratory coat & shoes while working with hazardous chemicals.
- Wear goggles and masks while working with those chemicals which are toxic & hazardous to eyes.
- If in any case chemical comes in contact with skin or eyes then immediately rinse it with cold water and take further medical help.
- Do not pipette or siphon chemicals by mouth.
- Wash hands with soap before leaving the work area, even if you were wearing gloves.
- Dispose of hazardous waste only in containers approved for that use.
- Use laboratory equipment only for its designated purpose.
- Combine reagents in the appropriate order (i.e. pour water first & then acid).
- Carefully handle glass bottles of chemicals which are large in size.
- Avoid exposures to gases, vapors & aerosols (USE FUMEHOOD).
- Immediately report all accidents to the laboratory in charge.
- Apparatus should be set as far back on the bench as conveniently possible so it’ll not tip onto the floor.
- When it is necessary to handle the equipment that is plugged in, be sure hands are dry and, when possible wear non conductive gloves and shoes with insulated soles.
- Do not use electrical equipments like dryer, continuously for too long as they may get very hot.
- Do not touch Physical Vapor Deposition system’s compressor while it’s on as it is very hot.
- Use caution when handling equipment after it has been operating.
- Always remember to turn off UPS of Physical Vapor Deposition system when you shut down the system.
- Always remember turn off all the appliances from main supply also once your work is done.
- Do not set up apparatus so that it is necessary to reach through assembly to turn water, gas or electricity on or off. Assemble apparatus so that control valves & switches will remain accessible in case of fire.
- Do not keep oven too close against wall or near other appliances.
- Disconnect the power source before servicing or repairing electrical equipment.
- All high voltage equipment must be properly marked and danger signs displayed.
- Be familiar with emergency procedures (exits, evacuation routes, fire extinguisher and first aid kits). LASER Safety Guideline In DIBSD Laboratory Class 3B continuous wave He-Cd LASER of wavelength 325nm and maximum power of 200mW is in use for PL spectroscopy system.
- Before turning on the laser pointer, always be sure that it is pointed away from yourself and others.
- Never look directly into a laser pointer.
- Never direct a laser pointer at another person.
- Watches and other jewelry that might enter the optical plane should not be allowed in the laboratory. All non-optical objects that are close to the optical plane should have a matte finish in order to prevent specular reflections.
LASER is a light source that can be dangerous to people exposed to it. Even low power lasers can be hazardous to a person's eyesight. The coherence and low divergence of laser light means that it can be focused by the eye into an extremely small spot on the retina, resulting in localized burning and permanent damage in seconds. Certain wavelengths of laser light can cause cataracts or even boiling of the vitreous humor, the fluid in the eyeball. Infrared and ultraviolet lasers are particularly dangerous, since the body's "blink reflex", which can protect an eye from excessively bright light, works only if the light is visible.
Lasers are classified by wavelength and maximum output power into the following safety classes:
Class 1: A class 1 laser is safe under all conditions of normal use. This means the maximum permissible exposure (MPE) cannot be exceeded. This class includes high-power lasers within an enclosure that prevents exposure to the radiation and that cannot be opened without shutting down the laser. For example, a continuous laser at 600 nm can emit up to 0.39 mW, but for shorter wavelengths, the maximum emission is lower because of the potential of those wavelengths to generate photochemical damage. The maximum emission is also related to the pulse duration in the case of pulsed lasers and the degree of spatial coherence.
Class 1:Class 1M: A Class 1M laser is safe for all conditions of use except when passed through magnifying optics such as microscopes and telescopes. Class 1M lasers produce large-diameter beams, or beams that are divergent. The MPE for a Class 1M laser cannot normally be exceeded unless focusing or imaging optics are used to narrow the beam. If the beam is refocused, the hazard of Class 1M lasers may be increased and the product class may be changed. A laser can be classified as Class 1M if the total output power is below class 3B but the power that can pass through the pupil of the eye is within Class 1.
Class 1:Class 2: A Class 2 laser is safe because the blink reflex will limit the exposure to no more than 0.25 seconds. It only applies to visible-light lasers (400-700 nm). Class-2 lasers are limited to 1 mW continuous wave, or more if the emission time is less than 0.25 seconds or if the light is not spatially coherent. Intentional suppression of the blink reflex could lead to eye injury. Many laser pointers are class 2.
Class 1:Class 2M: A Class 2M laser is safe because of the blink reflex if not viewed through optical instruments. As with class 1M, this applies to laser beams with a large diameter or large divergence, for which the amount of light passing through the pupil cannot exceed the limits for class 2.
Class 1:Class 3R: A Class 3R laser is considered safe if handled carefully, with restricted beam viewing. With a class 3R laser, the MPE can be exceeded, but with a low risk of injury. Visible continuous lasers in Class 3R are limited to 5 mW. For other wavelengths and for pulsed lasers, other limits apply.
Class 1:Class 3B: A Class 3B laser is hazardous if the eye is exposed directly, but diffuse reflections such as from paper or other matte surfaces are not harmful. Continuous lasers in the wavelength range from 315 nm to far infrared are limited to 0.5 W. For pulsed lasers between 400 and 700 nm, the limit is 30 mJ. Other limits apply to other wavelengths and to ultra short pulsed lasers. Protective eyewear is typically required where direct viewing of a class 3B laser beam may occur. Class-3B lasers must be equipped with a key switch and a safety interlock.
Class 1:Class 4: Class 4 lasers include all lasers with beam power greater than class 3B. In addition to posing significant eye hazards, with potentially devastating and permanent eye damage as a result of direct beam viewing, diffuse reflections are also harmful to the eyes within the distance called the Nominal Hazard Zone. Class 4 lasers are also able to cut or burn skin. In addition, these lasers may ignite combustible materials, and thus represent a fire risk, in some cases. Class 4 lasers must be equipped with a key switch and a safety interlock.