Physical Hazards

Laboratory hazards include not only chemical and biological hazards but physical hazards as well. These include, but are not limited to, slips, trips, and falls, sharps, compressed gases, pressurized equipment, electrical equipment, lasers, radiation, mechanical hazards, noise, and thermal hazards.

It is the responsibility of the Principal Investigator or laboratory supervisor to ensure that staff and students in laboratories are provided with adequate training and information specific to the physical hazards found within their laboratories. Reducing these risks in the laboratory can be accomplished through effective training and good housekeeping. Much like chemical hazards, awareness of these hazards, planning and procedures, use of personal protective equipment, and following basic safety policies can reduce or prevent accidents involving physical hazards. Laboratory personnel should be trained in the proper procedures for lifting, pulling and pushing, as well as the dangers of repetitive movements, and the handling requirements for different equipment.

Expand All|Collapse All


The common cause of many laboratory accidents is poor housekeeping. Good housekeeping is essential for preventing slips, trips and falls in the laboratory, potential hazards or spills should be quickly disposed of or cleaned by laboratory personnel as custodial staff generally are not as familiar with laboratory chemicals and their hazards.

The following are general housekeeping practices required for safety in the laboratory

  • Access to emergency equipment, showers, eyewash stations, and exits must never be blocked.
  • Keep aisles free from obstruction.
  • Keep all floors and work surfaces dry.
  • All work surfaces and floors should be cleaned regularly.
  • Promptly clean up all spills, including water spills and ice, and properly dispose of all spilled chemicals.
  • Keep all work areas, and especially work benches, clear of clutter and obstructions.  Properly store items when not in use.
  • Never place chemicals near the edge of a lab bench.
  • Keep all aisles, hallways, and stairs clear of all chemicals and other obstructions; never store or place chemicals on the floor without the use of a secondary container.
  • Do not store personnel items on the bench tops, or near chemicals or equipment that is in use.
  • Hallway doors of all laboratories must remain closed to maintain the proper negative airflow from the hallways into the labs.
  • Clean up work areas at the end of the procedure or class.


When handling glassware, always check for cracks and chips before washing, autoclaving or using it. Dispose of chipped and broken glassware immediately in a broken glass box. Handle glassware with care; avoid impacts, scratches or intense heating of glassware. The following general safety practices should be used when handling glassware in the laboratory:

  • DO NOT put broken glassware or sharps in the regular trash, instead request a broken glass box or sharps container from EHS.
  • Make sure that disposal containers for broken glass and sharps are well labeled and placed in low-traffic areas.
  • Properly dispose of broken glassware, any items contaminated with a hazardous substance need to be treated as hazardous waste and disposed in the appropriate waste container.
  • Never use cracked or chipped glassware; promptly discard these items in the broken glass container.
  • Do not stack beakers, flasks, etc.
  • If glassware is stored on open shelving use a storage bin to keep the glassware from falling off the shelf.
  • Wear appropriate gloves to clean glassware, not thin nitrile gloves intended for chemical protection.
  • Do not stack dirty or clean glassware.
  • Wash glassware carefully (dirty water can hide glass fragments).
  • Make sure you use the appropriate labware for the procedures and chemicals.
  • Be careful when inserting glass tubing into stoppers: use glass tubing that has been fire-polished, lubricate the glass, and protect your hands with heavy gloves.


To lessen the risk of accidental infection, the use of sharps should be avoided when alternate methods are available. Sharps are laboratory instruments or equipment capable of causing a puncture or cut including needles, scalpels, razor blades, glass Pasteur pipettes, slides, and broken glassware.

Sharps should be stored in a manner that prevents injury and should never be left unattended in a manner that could result in an accidental injury. Personnel should be familiar with proper storage, use, and disposal of sharps. For animal handlers, injury could occur when restraining an animal during a procedure involving the use of needles. The following precautions should be observed when working with sharps:

  • Always use safe needle devices (e.g., self-sheathing needle, retractable needle) unless it is infeasible for the work being conducted.
  • Use disposable needles and safety needle-locking syringes. Replace glass syringes with plastic disposable syringes whenever possible.
  • Never reuse needles that may be contaminated with infectious material.
  • Dispose of the entire unit (syringe and safety needle) into a sharps container.
  • Do not bend, shear, recap, or otherwise manipulate the needle.
  • Be sure that the safety needle is locked securely into the barrel before performing any operations.
  • Avoid quick and unnecessary movements while holding the sharps.
  • Do not use a syringe to forcefully expel a stream of hazardous fluid into an open vial.

Sharps must be disposed of in approved sharps containers and may not be disposed of in municipal waste. Sharps contaminated with particularly hazardous substances must be handled as hazardous waste. The Biological Safety Manual provides detailed safety guidelines for the safe use of needles and syringes with biohazardous material and animals.

Electrical Hazards

The major hazards associated with electricity are electrical shock and fire. Sparks from electrical equipment can serve as an ignition source for flammable or explosive vapors. The severity and effects of an electrical shock depend on several factors, such as the pathway through the body, the amount of current, the duration of exposure, and whether the skin is wet or dry. The following practices may reduce risk of injury when working with electrical equipment:

  • Only use extension cords temporarily.
  • If temporary wiring is required longer than eight hours, it must be disconnected before leaving the work area at the end of the workday.
  • Extension cords must be UL or Factory Mutual approved, grounded (three-prong), and heavy duty in type.
  • Replace electrical cords that have frayed or exposed wires. Qualified personnel should perform the replacement.
  • Avoid contact with energized electrical circuits.
  • Disconnect the power source and ensure that any capacitors are discharged before servicing or repairing electrical equipment.
  • Minimize the use of electrical equipment in cold rooms or other areas where condensation is likely to occur. If electrical equipment must be placed in such areas, mount it to a wall or vertical panel to reduce the effect of condensation.
  • If water or a chemical is spilled onto or around equipment, and it is safe to do so, shut off power at the main switch or circuit breaker and unplug the equipment before responding to the spill.
  • Only equipment with grounded (three-prong) plugs should be used. The third prong provides a path to ground that helps prevent the buildup of voltages that may result in an electrical shock or spark.
  • Live parts of electric equipment operating at 50 volts or more (e.g., electrophoresis devices) must be guarded against accidental contact.
  • Use circuit-protection devices that are designed to automatically limit or shut off the flow of electricity in the event of a ground fault, overload, or short circuit in the wiring system.
  • Determine if laboratory outlets provide adequate amperage and appropriate voltage for the electrical requirements of all equipment used. Certain pieces of equipment may require other than standard 120-volt outlets.

For assistance with electrical requirements, contact Facilities Management.


Principal Investigators and laboratory supervisors must provide specific operating procedures, safety information, and training for work involving lasers. For more information on Laser Safety, click here. 


Use of radioactive materials requires prior authorization from the Radiation Safety Officer.
Radioisotope include both sealed and unsealed sources.

  • Sealed:  gas chromatographs, scintillation counters
  • Unsealed: Tritium (3H), Carbon 14 (14C), Phosphorus 32 (32P)

For more information on Radiation Safety, click here. (will create link once page is completed)

Pressurized Equipment

Working with hazardous chemicals at high or low pressures requires planning in advance and special precautions. Any system that increases or decreases ambient pressure inside of a vessel presents a potential pressure hazard (e.g., implosion, explosion). The guidelines below should be followed when using a pressurized system.

  • All work at high pressure must be conducted in vessels designed, constructed, and tested for this purpose; all such vessels must be equipped with appropriate pressure relief and any other necessary control devices.
  • Vessels used for high-pressure work must be inspected prior to use for any visible signs of damage; and removed from service or repaired by a qualified technician if any damage is found.
  • Hydrostatically test equipment before initial use and then periodically, based on use, for integrity.
  • Conduct all vacuum operations behind a shield or in a chemical fume hood, and wear appropriate PPE (glasses, goggles, or face shield).
  • Ensure proper strain relief for all hoses and connections.
  • Vent all vacuum exhaust into a chemical fume hood.
  • Use glassware specifically designed for vacuum operations (e.g., Erlenmeyer filtration flask).
  • Inspect vacuum glassware before and after each use. Discard any glass that is chipped, scratched, broken, or otherwise stressed.
  • Wrap all glassware exposed to vacuum in friction tape, loose cloth, or metal screen to contain the glass in the event of implosion.
  • Ensure proper belt guards are in place on pumps before operation.
  • Always use traps, scrubbers, and/or filters on vacuum lines to:
    • prevent chemicals from being drawn into the pump, building vacuum line, or water drain.
    • protects lab personnel who work on the vacuum lines or system, and
    • prevents vapors and odors from being released into the laboratory or system exhaust.
  • Avoid using mechanical pumps for large volume distillation or concentration of volatile chemicals; use a water or steam aspirator instead.
  • Replace and properly discard vacuum pump oil that is contaminated with condensate.
  • Place secondary containment under equipment.
  • Do not place a pump in an enclosed or unventilated area.

Compressed Gases

Compressed gases are commonly used in laboratories and may present a wide variety of hazards:

  • Do not handle or use a cylinder without receiving hands-on training from the PI/LS or other qualified individual.
  • Never roll or drag a cylinder. Always use a cylinder cart to move cylinders.
  • Cylinder valves must be protected from physical damage by means of a protective cap, collar, or other similar device while in storage and during transport.
  • Refer to the chemical SDS and follow manufacturer’s directions when attaching distribution lines and regulators to a cylinder. Not all distribution lines are compatible with all types of compressed gas, and some regulators are not interchangeable among cylinders.
  • Wear a face shield when connecting and disconnecting cylinder regulators and distribution lines.
  • Ensure that gas distribution lines are accessible and as short as safety permits.
  • Clearly label distribution lines and outlets with the product name.
  • Use check valves to prevent flow reversal in cylinder distribution lines when necessary.
  • Install flash arrestors on supply lines for flammable gas cylinders to protect cylinder from explosion.
  • Visually inspect distribution lines for leaks, cracks, holes, or kinks.
  • Inspect cylinders regularly for leaks, corrosion, cuts, dents, and any other damage which may affect operation. If damage is observed, the cylinder must be taken out of operation and returned to the vendor.
  • Check for leaks with an acceptable leak-detecting liquid, such as Snoop®. Never attempt to identify leaks with an open flame.
  • Never remove the cylinder valve handle, or attempt to repair, refill, or alter the cylinder in any other way. Cylinder alterations and repairs may only be made by the manufacturer.
  • When opening the valve on a cylinder, position the valve facing away from you and other personnel. Open the valve slowly and completely.
  • Do not use wrenches, pliers, or other hand tools to open a cylinder. If a cylinder is unable to be opened by a hand, return the cylinder to the manufacturer.
  • After each use, close the cylinder valve and bleed distribution lines. Gas cylinders may contain gases that are, inert, oxidizing, flammable, toxic, corrosive, or asphyxiants.
  • Never empty a cylinder to a pressure lower than 172 kPa (25 psi).
  • When a cylinder is empty, close the valve, remove the regulator, replace the valve cap, and mark the cylinder as “Empty.”
  • If there is a possibility that the contents of a cylinder are contaminated, label the cylinder as possibly contaminated with the name of the contaminant.
  • Return all compressed gas cylinders to the supplier when empty or no longer in use. Contact EHS for assistance in arranging cylinder returns and disposal if the supplier is unknown or an unlabeled cylinder is found.
  • Unsecured cylinders can be tipped over, causing serious injury and damage, uncapped valves can be sheared off by impact, causing a rapid release of pressure resulting in injury to lab personnel and damage to property.
  • Rigid plastic tubing may shatter if pressure limits are exceeded, appropriate metal tubing should be used when possible.

For more information on the hazards of compressed gas cylinders and how to work safely with them review Chemical Hazard Assessment Compressed Gas.

Mechanical and Machine Hazards

Procedures involving devices or equipment with moving parts can present several types of mechanical hazards which must be controlled to work safely with them in the laboratory.

  • Pinch/Nip Points: Where two parts moving converge, examples include: belt drives, gear drives, or rollers. Where guarding or shielding cannot be employed, users must avoid contact with hands or clothing at pinch points. Do not service or attempt to unjam a machine while it is operating, or the engine is running.
  • Shear Points: Where the edges of two moving parts move across one another or where a single sharp part moves with enough speed or force to cut material. Be aware of the potential hazards of cutting and shear points on equipment that is not designed to cut or shear. Guarding is not always possible for these hazards.
  • Wrap Points: Rotating components such as spinning shafts. Once clothing or hair is caught it begins to wrap; pulling only causes the wrap to become tighter. Rotating or moving parts that continue to move after being powered off are particularly dangerous, allow time for parts to stop moving.
  • Crush Points: Points that occur between two objects moving toward each other or one object moving toward a stationary object. Never place any part of your body between two objects moving toward one another. Use adequate blocking or lock-out devices when working with equipment.
  • The following methods can be used to control and reduce these mechanical hazards.
    • Identify and avoid areas where pinch, shear or wrap points occur.
    • Maintain manufacturer-installed warning labels, and place highly visible warning labels on parts and equipment to identify pinch, shear or wrap points not previously labeled.
    • Do not reach over, around or work on rotating parts.
    • Wear close-fitting clothing and remove jewelry.
    • Do not work with equipment when fatigued, or in a hurry, it can contribute to incidents.
    • Before working on equipment, turn it off. Make sure any moving parts have completely stopped. Lock it out and tag it out.
    • Replace any shields or guards that have been removed for maintenance.

Electromagnetic Fields

“Non-Ionizing Radiation” refers electromagnetic radiation not energetic enough to cause ionizations in matter. This category includes radio waves, microwaves, and low frequency magnetic and electric fields. The superconducting magnet of NMR and MRI equipment produces strong magnetic and electromagnetic fields that can interfere with the function of cardiac pacemakers. Users with such devices should consult with their physician before working with this type of equipment.

The following precautions are recommended for work with NMR or MRI:

  • Post warning signs in areas with strong magnetic fields.
  • Measure stray fields with a gaussmeter and restrict public access to areas of 5-gauss or higher.
  • Strong magnetic field can pull nearby unrestrained magnetic objects into the magnet with considerable force. Keep all ferromagnetic tools, equipment and personal items outside the 5-gauss line of the magnet.
  • Protect all exposed skin from contact with cryogenic (liquid) helium and nitrogen; wear appropriate personal protective equipment; face shield, apron, and insulated gloves during Dewar servicing.
  • Ensure that room ventilation is adequate to remove the helium or nitrogen gas exhausted by the instrument.
  • Immediately evacuate the laboratory in the event of an oxygen monitor alarm and contact EHS, 3-8448.

Thermal Hazards

Heat hazards within laboratories can occur from many sources. The following guidelines can prevent heat related injuries.

  • In laboratories where open flames are used, a fire extinguisher must be available and laboratory personnel should know its location. training is available through EHS.
  • Never leave open flames (from Bunsen burners, etc.) or hot plates unattended.
  • Heating devices should be set up on the benchtop, fume hood, or other stable support device and away from any ignitable materials (flammable solvents, temperature sensitive material, and other combustibles).
  • Heating devices should not be used near water sources to prevent shock.
  • Heating devices should be equipped with a temperature controller to prevent overheating;
  • Provisions should be included in processes to prevent thermal runaway, and a means to cool the dangerous reactions should be available.
  • Post warning signs to prevent accidental burns.
  • When using oven(s) ensure the following:
    • Heat generated is adequately removed from the area.
    • If toxic, flammable, or otherwise hazardous chemicals are evolved from the oven, it must be equipped with a canopy or be enclosed within a chemical fume hood.
  • Heating mantles or steam baths should be used when heating flammable solvents to prevent accidental ignition.
  • When using heating baths ensure the following:
    • Heating baths must be set up on a stable surface.
    • Thermostats must be used to monitor the temperature of combustible liquids to ensure they do not exceed the flash point of the liquid.
  • Use heat-resistant gloves when handling hot items.
  • Use flame-resistant gloves when handling reactive materials or heating solvents at or near their flash point.
  • Use a stir bar or similar device to ensure even heating of the liquids (to prevent thermal runaway and boil-overs)
  • When using Bunsen burners:
    • Inspect tubing prior to using the burner for cracks and ensure a tight fit to the burner and to the gas spigot.
    • Inspect the tubing for gas leaks that could result in accidental ignition.
    • Stand back from the burner when lighting the gas.
    • Once the gas has been turned on, immediately light the burner utilizing a sparker or lighter with an extended nozzle. Never use a match to ignite a burner.
    • Regulate the flame to an appropriate level. Flames should not extend beyond the bottom edge of the surface being heated
    • If a Bunsen burner goes out unexpectedly, turn off the gas, inspect the hose connection and the burner, and begin the lighting process again. If the burner fails to light, turn off the gas and check the gas source and/or replace the burner.

    In addition to the laboratory safety guidelines listed above, the procedures below should be followed when working with Ultra-cold freezers (-80°C), cryogenic liquids and dry ice:

    • Wear insulated gloves that are thick enough to provide protection against burns and loose enough to be removed easily with one hand in the event that the cryogenic liquid becomes trapped close to the skin.
    • Wear goggles and a face shield when transferring cryogenic liquids.
    • Use caution when adding items to LN2 rapid addition can result in splashes to the face and hands.
    • Do not store dry ice in sealed containers. As dry ice sublimates, it can generate tremendous pressure and rupture sealed containers.
    • Never release cryogenic liquids or dry ice into a laboratory sink as they may cause pipes to rupture.
    • Never allow dry ice to sublimate or cryogenic liquids to boil off even at small amounts in a laboratory, as this will displace oxygen and create an asphyxiation hazard.
    • Never seal containers without proper venting or pressure relief of cryogenic liquids as this will cause an unsafe buildup of pressure that may result in a boiling liquid expanding vapor explosion (BLEVE).


3D printing, also known as additive manufacturing, is becoming more common in maker spaces and in research and instructional labs. 3D printers, their print materials, products and waste may present health or safety hazards.

  • Contact with hot extruders and motors or hot resin could result in burns or other hand injuries.
  • Toxic volatile compounds can be emitted via outgassing of the thermoplastic resins during heating.
  • Ultra-fine particles produced during the filament melting, extrusion process, and sanding or grinding of finished product can be an irritant or flammable hazard.
  • Some printers use lasers or ultraviolet light and direct exposure could damage vision.
  • Some printers employ corrosive baths to clean manufactured parts, users must be trained on those hazards and proper PPE must be worn to protect users from burns.
  • Some printers use reactive metal powders such as titanium to manufacturer products, these materials can be highly flammable, EHS must be consulted before purchase or use in 3D printing.

The following precautions must be followed when working with 3D printers:

  • Only those trained and authorized may use 3D printers.
  • Adequate ventilation must be available to control dust and ultra-fine particles generated by the printing process. The use of a chemical fume hood or other local exhaust ventilation may be necessary depending on the hazard present.
  • Position workstations away from printers to minimize breathing of emitted particles.
  • When possible use materials with lower emissions that are recommended by the manufacturer, such as polylactic acid (PLA) instead of acrylonitrile butadiene styrene (ABS), since ABS is more toxic.
  • Ensure that printers with lasers or UV light are properly shielded to prevent eye exposure.
  • Eating, drinking, applying cosmetics, chewing gum, or handling contact lenses in rooms that contain 3D printing operations must be prohibited. Users must wash their hands thoroughly after working with 3D printers.
  • Proper PPE, safety glasses and gloves at a minimum, must be worn when operating the printer and cleaning or finishing parts.
  • Do not sweep or use other dry methods to clean areas around 3D printer as this may create airborne particles.
  • Review product Safety Data Sheets (SDSs) for material specific safety information before using anything in the 3D printer.
  • Never bypass installed safeguards.
  • Before each, use inspect the 3D printer for any damaged wiring and safeguards. Do not use the printer if problems are found.
  • Report all printer concerns, incidents and near misses to the Principal Investigator or Lab Supervisor.
  • Principal Investigators and Lab Supervisors must approve all 3D printer projects and purchase and use of print media in consultation with EHS.

Return to Top

Print Friendly, PDF & Email