Safety and Why It Matters

Electrical safety is extremely important to be both knowledgeable and aware of at all times. As an introduction, here are some brief facts regarding electrical safety in America. About 1000 people in the U.S. die from electric shock every single year. The shocks themselves having voltages of 50V and less are less likely to cause death. This is because higher voltages better overcome the natural resistance of the skin. If someone is working with electrical equipment and gets shocked, a shock circuit through both hands is more dangerous than through one hand. Water can increase shock risk and batteries can also increase dangers of short circuits.

Types of Electrical Injury

Provided below are a few main types of electrical injury.

• Electric Shock -- A reflex response occurs when electrical current passes over or through a worker’s body, often involves burns and abnormal heart rhythm and unconsciousness.

• Electrocution -- Electrical current passes over or through a worker’s body resulting in a fatality.

• Electric Shock Drowning -- Can directly electrocute a swimmer in the water or cause a level of paralysis that ultimately results in drowning.

• Falls -- Electric shock may cause muscles to contract causing a worker to lose balance and fall.

• Burns -- Occurs when a worker contacts energized electrical wiring or equipment, most often occur on the hands and feet.

Understanding Electric Shocks & the Human Body

Researchers in the 1950-60s era conducted experiments to see how the human body responded to electrical shocks. The data from these, and similar, experiments informs our understanding of how humans respond to electrical shock, and the variety of factors that can affect this. Figure 1 pictures the estimated effects from various electric shocks.

Additional Resources:

• A. W. Smoot and C. A. Bentel, "Electric Shock Hazard of Underwater Swimming Pool Lighting Fixtures," in IEEE Transactions on Power Apparatus and Systems, vol. 83, no. 9, pp. 945-964, Sept. 1964
  https://ieeexplore.ieee.org/document/4766095

• Engineering and Technology Wiki, Ohm's Law
  https://ethw.org/Ohm%27s_Law

• Fish, R. M., & Geddes, L. A. (2009). Conduction of electrical current to and through the human body: a review. Eplasty, 9.
  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2763825/pdf/eplasty09e44.pdf

• Kouwenhoven, W. B. (1937). Electrical Accidents
  https://ieeexplore.ieee.org/document/5057695

• Marina Risk Reduction, NFPA 2017
  https://www.nfpa.org/News-and-Research/Data-research-and-tools/Electrical/Marina-Risk-Reduction

• NASA Human Responses to Electricity: A Literature Review
  https://ntrs.nasa.gov/citations/19730001338

• Prevention Strategies for Electrical Hazards, 2008 National Safety Council
  https://www.osha.gov/sites/default/files/2018-12/fy07_sh-16610-07_01_pg-module_1.pdf

• University of Pittsburgh, How voltage, current, and resistance relate
  https://people.cs.pitt.edu/~wiebe/courses/CS447/Info/howVoltageCurrentResistanceRelate.html

By: Dylan Pearson, Biological Systems Engineering, Undergraduate Student; John Ignosh, Extension Specialist, Biological Systems Engineering, Virginia Tech; Shaun White, Whitehouse Solar Energy; Matt Booher, Crops and Soil Extension Agent, Virginia Cooperative Extension