| Which of the following can lower the amount of current needed to cause electricity-induced injury? | View Page |
| Which of the following techniques should be used to free someone who is "frozen" to a live electrical line? | View Page |
| If a person comes in direct contact with an electrical source and sustains an electrical shock, which of the following actions should be taken once the current has been shut off and/or the person has been freed from contact with the current? | View Page |
| Which of the following identifies a major mechanism of electricity-induced injury? | View Page |
| What attribute of alternating current (AC) increases its potential for causing electricity-induced injury? | View Page |
| Precautionary information that pertains to a laboratory instrument or appliance can only be obtained by contacting the manufacturer. | View Page |
| If a co-worker sustains an electrical burn, what action should be taken once the source of electricity has been disconnected? | View Page |
| Introduction Electrical hazards are present in all laboratories. Because of this, adherence to all electrical safety standards is essential in preventing electrical accidents. | View Page |
| Electricity-induced Injury The major mechanisms of electricity-induced injury include: Electrical energy causing direct tissue damage Conversion of electrical energy into thermal energy causing massive tissue destruction Direct trauma resulting from falls or violent muscle spasms | View Page |
| Factors that Determine the Degree of Electricity-induced Injury The degree of electricity-induced injury is dependent on: The amount of electrical energy that is delivered The resistance that is encountered The type of current The current pathway The duration of contact Contact with alternating current (AC) is more likely to cause sustained muscular contraction than contact with direct current (DC). This sustained muscular contraction may prevent the victim from releasing the electrical source, increasing the duration of contact and the amount of electrical energy that is delivered. The resistance that is encountered is dependent on the body tissue that is traversed by the electrical current. Generally, tissues with high fluid electrolyte concentrations will conduct electricity the best. Bone is the most resistant tissue to electrical flow. Skin impedes electrical current, but resistance is dependent on the skin's thickness and moisture. Wet skin can reduce the contact resistance of the body.The degree of electricity-induced injury is also determined by which tissues are in the current pathway. Electrical current that passes through the head or thorax produces the most serious injuries including fatal arrhythmia, direct cardiac damage, respiratory arrest, direct brain injury, and paralysis. | View Page |
| Extension Cords and Adapters Electrical extension cords should not be used except in emergency situations. If an extension cord needs to be used, it must consist of 16 gauge or larger wire and must contain a ground wire. An extension cord should not be fastened with staples or hung in any way that could damage the outer covering or insulation. The wiring should be tested for physical integrity, polarity, and continuity of grounding at the time that it is used. An electrical extension cord cannot be used as a substitute for appropriate distribution of electrical power. Adapters designed to increase the number of outlets, and three-to-two-prong adapters should not be used. | View Page |
| Unplugging an Electrical Cord Electrical cords should be unplugged by holding the cap and not by pulling on the cord. Hands should not be wet when plugging or unplugging electrical cords. Moisture will reduce the contact resistance of the body, and electrical insulation is more subject to failure. Unplug all equipment during servicing. | View Page |
| Ground A ground is a conducting connection between an electrical circuit or equipment and the earth, or between an electrical circuit and some conducting body that serves in place of the earth.The purpose of a ground is to prevent the buildup of voltages that may result in a hazardous situation for the connected equipment and/or for the person operating the equipment.All electrical equipment in the laboratory that is not clearly marked as "double-insulated" must be grounded by using a three-pronged power cord. Three-to-two-prong adapters cannot be used because they interrupt the continuity of the grounding. | View Page |
| Space heaters Electrical space heaters are prohibited unless they are approved for use and inspected by your facilities management department. Space heaters are not permitted in hospital sleeping areas or in laboratories containing flammable liquids or gases. The heating elements in the space heater cannot exceed 212 degrees Fahrenheit, and cannot be exposed elements. Heaters with hot elements, even with guards, are not allowed. The approved heater must be connected directly to an outlet without the use of an extension cord. Reference: NFPA 101 Life Safety Code. National Fire Protection Agency. Paragraph 18/19.7.8. Quincy, MA: 2006. | View Page |
| Checks and Inspections All laboratory instruments and appliances should be checked for ground integrity and current leakage before initial use, after repair or modification, and any time a problem is suspected.Periodic checks should be made on all electrical wires. If frayed wires are found, the equipment should be immediately removed from use and repaired.Report to your supervisor any shocks or tingling received from electrical equipment. | View Page |
| Electrical Hazard Awareness Manufacturers are required to label appliances and instruments with electrical ratings including voltage, frequency, current, and/or wattage of the device and precautionary statements if applicable. Operating and safety instructions are provided with electrical equipment. It is prudent for personnel to familiarize themselves with this information before using the equipment. Personnel should be aware of the hazards associated with the use of defective electrical equipment. Defective equipment should be tagged and repaired or discarded. Keep liquids, chemicals, and heat sources away from electrical outlets and cords. | View Page |
| Electrical Shock Direct contact with electrical current can cause sustained muscular contraction that may prevent the victim from releasing the electrical source. Shut off the electrical current if it can be done safely by unplugging the cord or turning off the main power switch. Merely turning off an instrument or appliance will not always stop the flow of electricity.If the current cannot be turned off, a non-conductive material such as a broom, chair, rug, or rubber mat can be used to push the victim away from the source of the current. Don't use a wet or metal object, and do not touch the victim with your bare hands. Verify that the object that is used does not have a metal core. As an extra precaution, stand on something dry and non-conducting such as a mat or stack of paper while attempting to free the victim from the electrical current. Call a physician immediately. Lower the victim's head to slightly lower than the trunk of the body, and elevate the legs. Cover the victim with a blanket or coat. Begin CPR if the victim's breathing and/or pulse has stopped or seems dangerously slow or shallow. | View Page |
| Electrical Burns For electrical burns: Disconnect the source of the electricity if it can be done safely. Refer the victim for emergency care. No matter how minor the burn may appear, the victim must be evaluated by a doctor immediately. The amount of internal damage done by electricity may not be immediately apparent. | View Page |