Lecture 3

Question 1

Because of the quantity and variety of chemicals used by the chemical process industries, chemical engineers must be knowledgeable about:

Answer 1

the way toxicants enter biological organisms
the way toxicants are eliminated from biological organisms
the effect of toxicants on biological organisms, and
methods to prevent or reduce the entry of toxicants into biological organisms

Question 2

Fundamental Principle of Toxicology:

Answer 2

There are no harmless substances, only harmless ways of using substances.

Question 3

qualitative and quantitative study of the adverse effects of toxicants on biological organisms

Answer 3

Toxicology

Question 4

can be a chemical or physical agent, including dusts, fibers, noise, and radiation.

Answer 4

Toxicant

Question 5

property of a toxicant describing it effect on biological organism

Answer 5

Toxicity

Question 6

likelihood of damage to biological organism based on exposure resulting from transport and other physical factors of usage.

Answer 6

Toxic Hazard

Question 7

Routes of Entry

Answer 7

Ingestion, Inhalation, Absorption/Injection

Question 8

Routes of entry: Ingestion

Answer 8

through the mouth into the stomach

Question 9

Routes of entry: Inhalation

Answer 9

through mouth/nose into lungs

Question 10

Route of Entry: Absorption/Injection

Answer 10

through skin

Question 11

Plays the most significant role in toxicants entering the body through ingestion

Answer 11

gastrointestinal tract

Question 12

plays a role in absorption and injection routes of entry

Answer 12

skin

Question 13

for toxicants entering the body through inhalation

Answer 13

respiratory system

Question 14

rule of thumb for dust particles:

Answer 14

the smaller the particles, the farther they penetrate into the respiratory system

Question 15

toxicants are eliminated by the following routes:

Answer 15

Excretion
Detoxification
Storage

Question 16

Minor routes of toxicant exit:

Answer 16

skin(sweat), hair, and nails

Question 17

toxicant eliminated through kidneys, liver, lungs, or other organs

Answer 17

excretion

Question 18

toxicants are eliminated by changing the chemical into something less harmful by biotransformation, usually processed by the liver but can also occur in the blood, intestinal tract wall, skin, kidneys, and other organs.

Answer 18

Detoxification

Question 19

toxicants are eliminated by depositing of chemical agent in the fatty tissue, bones, blood, liver, and kidney

Answer 19

storage

Question 20

Toxic chemicals disrupt the normal function of the body. effects can be:

Answer 20

local - at the site of the exposure
systemic - affecting the entire body or target organs

Question 21

medical examinations: pre-employment and periodic

Answer 21

to determine whether exposures have occurred before substantial symptoms appear

Question 22

tests that may be conducted:

Answer 22

spirometry - respiratory problems
electroencephalogram (EEG) or other psychological tests - for nervous system disorders
physical exam - changes in skin texture, pigmentation, hair or nail appearance
blood counts - measure hemoglobin, RBC/WBC, platelet and other parameters needed
kidney function test - creatinine content of urine
liver function test - through blood and urine

Question 23

Factors in toxicological studies

Answer 23

1. toxicant (chemical composition and physical state)
2. target or test organism (simplee single cell to higher animals)
3. effect or response to be monitored
4. dose range (depend on method delivery)
5. period of the test

Question 24

to quantify the effects of the suspect toxicant on a target organism

Answer 24

toxicological studies

Question 25

Type of toxicities by length of time:

Answer 25

acute toxicity chronic toxicity

Question 26

effect of a single exposure or series of exposure in a short period of time. basis for most toxicological studies.

Answer 26

acute toxicity

Question 27

effect of multiple exposures occurring over a long period of time

Answer 27

chronic toxicity

Question 28

if several chemical are involved, the toxicants might interact:

Answer 28

additively synergistically potentiately antagonistically

Question 29

combined effect is the sum of the individual effects

Answer 29

additively

Question 30

combined effect is more than the individual effects

Answer 30

synergistically

Question 31

presence of one increase the effect of the other

Answer 31

potentiately

Question 32

both counteract each other

Answer 32

antagonistically

Question 33

Classifications of dose:

Answer 33

1. effective dose 2. lethal dose 3. toxic dose

Question 34

toxicant dose at c=which the response is minor and reversible

Answer 34

effective dose (ED)

Question 35

toxicant dose poses a risk of death or lethality

Answer 35

lethal dose (LD)

Question 36

used for gases (toxicant dose0

Answer 36

lethal concentration

Question 37

dose where the response is toxic, not lethal but causing irreversible damage

Answer 37

toxic dose (TD)

Question 38

established by the American Conference of Governmental Industrial Hygienists (ACGIH)

Answer 38

Threshold Limit Values (TLV)

Question 39

three types of TLV

Answer 39

TLV-TWA TLV-STEL TLV-C

Question 40

time weighted average for a normal 8-hr workday or 40-hr work week

Answer 40

TLV-TWA

Question 41

short term exposure limit; max. concentration to which workers can be exposed for a period of up to 15 min continuously without suffering intolerable irritation, chronic or irreversible tissue change, narcosis of sufficient degree to increase accident proneness

Answer 41

TLV-STEL

Question 42

ceiling limit

Answer 42

TLV-C

Question 43

Threshold dose defined by OSHA

Answer 43

permissible Exposure Limit (PEL)

Question 44

dose or quantity where exposure must be avoided under any circumstances

Answer 44

Immediate Danger to Life and Death (IDLH)

Question 45

for some toxicants, particularly carcinogens, exposures at any level are not permitted

Answer 45

Zero Threshold