Chapter 6: Agents and Hazards

Question 1

Hazard

Answer 1

any condition or changing set of circumstances that has the potential to cause an injury (or illness)

Question 2

Agents

Answer 2

any substances to which a human may be exposed at work or at home
o Physical
o Chemical
o Biological

Question 3

Biohazards

Answer 3

hazards created by exposure to infectious microorganisms, proteins, or nucleic agents

Question 4

Chain of infection

Answer 4

the process and conditions by which biological agents are spread from one host to another

Question 5

Reservoir

Answer 5

the home or environment where the biological agent grows and multiplies

Question 6

Portal of exit

Answer 6

the path by which a biohazardous agent leaves its host

Question 7

Mode of transmission

Answer 7

the means or channel by which an agent is carried from one host to another

Question 8

Portal of entry

Answer 8

the path by which a biohazardous agent gains access to a new host

Question 9

Susceptible Host

Answer 9

an individual or animal that becomes infected with a biohazardous agent

Question 10

Chemical Agents

Answer 10

hazards created by exposure to chemicals

Question 11

Toxicity

Answer 11

o Ability to cause injury to human biological tissue
o Potential degree of seriousness of the hazard of exposure
o Toxicology is the scientific study of poisons

Question 12

Aerosols

Answer 12

airborne respirable contaminants, such as liquid droplets or solid particulate, dispersed in air, that are of a fine enough particle size to remain suspended for a time

Question 13

Routes of Entry for Chemicals Include: (4)

Answer 13

o Respiration (inhaling)
o Skin absorption
o Ingestion
o Skin penetration (puncture wounds)

Question 14

Respiration

Answer 14

o Most human exposure to chemicals due to breathing airborne contaminants
o Five levels of defense:
 Nose
 Interior of the nasal passage where turbinates are found (spiral or spongy sections of the respiratory system that have a centrifugal effect to help remove aerosols)
 Tiny hairs or cilia and mucus
 Aerodynamic characteristics of the human lung
 Alveoli in lungs (tiny air sacs that dispose of any impurities via the lymph system)

Question 15

Skin Absorption

Answer 15

o The ability of a chemical to pass easily through the skin is often closely associated with its level of toxicity
o Chemicals that are not rapidly absorbed may produce a localized irritation (dermatitis) which may cause the skin to become white and dry

Question 16

Ingestion

Answer 16

o Many solvents enter through the mouth and digestive system

Question 17

Penetration

Answer 17

o When the skin is cut or punctured by any sharp object
 Object may be contaminated with a hazardous chemical
o Particular risk for health care workers

Question 18

Inorganic Solvents

Answer 18

1. Acids (1)

2. Bases (14)

Question 19

Biological Agents

Answer 19

• Natural organisms that can be a risk to humans
• Well known diseases resulting from biological agents are:
  o Legionnaires’ disease
  o AIDS
  o SARS

Question 20

SARS

Answer 20

• Severe acute respiratory syndrome
• Viral infection (SARS coronavirus)
• Morality rate about 10% according to WHO
• Symptoms
  o Flu like (fever, lethargy, cough, sore throat, gastrointestinal problems)
  o Appears 2 – 10 days post exposure
• Treatment
  o Antibiotics are ineffective
  o Antipyretics, oxygen, and ventilation work better

Question 21

Engineering controls for hazard control measures

Answer 21

best is elimination, areas should be properly enclosed, built-in protective systems, ventilation systems, construction seals, sharp disposal containers for needles, or automated equipment like toilets and sinks

Question 22

Work practices and procedures for hazard control measures

Answer 22

good housekeeping (surfaces are clean, etc.), spills must be cleaned up properly, preventive maintenance such as air filters on exhaust, and thorough recordkeeping (records be kept of employee exposure, workplace air monitoring, and equipment breakdowns and repairs

Question 23

Administrative control for hazard control measures

Answer 23

training in safe operating and emergency procedures

Question 24

Personal protective equipment (PPE) for hazard control measures

Answer 24

respiratory protection, each device must be matched to the chemical and biological exposure

Question 25

Personal hygiene practices for hazard control measures

Answer 25

remove outer protective clothing, avoid touching the face with contaminated hands, wash hands, and remove work clothes before leaving work

Question 26

Medical surveillance (administrative control for hazard control measures)

Answer 26

ensure that employees who are exposed to agents are not subjected to situations in which their health will be jeopardized

Question 27

Workplace Hazardous Materials Information System

Answer 27

• A comprehensive communication system designed to outline the safe use of hazardous products via labels, safety data sheets, and worker education and training programs
• Based on three elements
  1. Alert the worker of potentially hazardous product
  2. Safety data sheets outlining a product’s potentially hazardous ingredient(s) and procedures for safe handling of the product
  3. Employee training
• Supplier labels must include product identifier, initial supplier identifier, pictograms, signal word, hazard statements, precautionary statements, and supplemental label information