HAZARD ANALYSIS AND SHOCK

Question 1

It is silent, invisible, odorless, and has an “automatic” aspect to it

Answer 1

Electricity

Question 2

1800s

Answer 2

electricity is harmless

Question 3

1900s

Answer 3

electricity entails great hazard

Question 4

The process of collecting and interpreting information on hazards and conditions leading to their presence.

Answer 4

hazard analysis

Question 5

There Are Three Components of Electrical Power Hazard:

Answer 5

shock, arc, blast

Question 6

The physical stimulation or trauma that occurs as a result of electric current passing through the body.

Answer 6

shock

Question 7

The heat and light energy release that is caused by the electrical breakdown and subsequent electrical discharge through an electrical insulator, such as air.

Answer 7

arc

Question 8

The explosive effect caused by the rapid expansion of air and other vaporized materials that are superheated by the sudden presence of an electric arc.

Answer 8

blast

Question 9

Is the physical stimulation that occurs when electric current flows through the human body. The distribution of current flow through the body is a function of the resistance of the various paths through which the current flows.

Answer 9

electric shock

Question 10

The final trauma associated with electric shock is usually determined by the most critical path called the

Answer 10

shock circuit

Question 11

It is the path that electric current takes through the body. If the shock circuit includes critical organs, severe trauma is more likely than if it does not.

Answer 11

shock circuit

Question 12

Effects of Electrical Shock

Answer 12

burning, cell wall damage

Question 13

are caused by electric current are almost always third-degree because the burning occurs from the inside of the body. This means that the growth centers are destroyed. Electric-current burns can be especially severe when they involve vital internal organs.

Answer 13

burning

Question 14

Research funded by the Electric Power Research Institute (EPRI) has shown that cell death can result from the enlargement of cellular pores due to high-intensity electric fields. This trauma called electroporation allows ions to flow freely through the cell membranes, causing cell death.

Answer 14

cell wall damage

Question 15

Influencing Factors

Answer 15

1. Physical Condition and Physical Response
2. Current Duration
3. Frequency
4. Voltage Magnitude
5. Current Magnitude
6. Nominal Resistance Values for Various Parts of the Human Body
7. Nominal Resistance Values for Various Materials
8. Nominal Human Response to Current Magnitudes
9. Parts of the Body

Question 16

A given amount of current flow will usually cause less trauma to a person in good physical condition. Moreover, if the victim of the shock has any specific medical problems such as heart or lung ailments, these parts of the body will be severely affected by relatively low currents. A diseased heart, for example, is more likely to suffer ventricular fibrillation than a healthy heart.

Answer 16

Physical Condition and Physical Response

Question 17

The amount of energy delivered to the body is directly proportional to the length of time that the current flows; consequently, the degree of trauma is also directly proportional to the duration of the current.

Answer 17

Current Duration

Question 18

The table below lists the broad relationships between frequency and the harmful effects of current flow through the body. Note that at higher frequencies, the effects of Joule (I2t) heating become less significant. This decrease is related to the increased capacitive current flow at higher frequencies.

Answer 18

Frequency

Question 19

Historically, little attention was paid to the effect that voltage magnitude has on an electrical trauma. It was assumed that a 200-V source would create the same amount of physical trauma that a 2000-V source would—assuming that the current magnitude is the same. In fact, higher voltages can be more lethal for at least three reasons:

Answer 19

Voltage Magnitude

Question 20

At voltages ___ ____ the electrical pressure may be sufficient to puncture the ____.

Answer 20

above 400V, epidermis

Question 21

The degree of electroporation ____ for greater cellular voltage gradients.

Answer 21

is higher

Question 22

Higher voltages are more likely to create ___ ____.

Answer 22

electrical arcing

Question 23

The magnitude of the current that flows through the body obeys Ohm’s law

Answer 23

current magnitude

Question 24

Current flow affects the various bodily organs in different manners. For example, the heart can be caused to fibrillate with as little as 75 mA. The diaphragm and the breathing system can be paralyzed, which possibly may be fatal without outside intervention, with less than 30 mA of current flow. The specific responses of the various body parts to current flow are covered in later sections.

Answer 24

parts of the body