Chapter 2 Process Safety

The respiratory system is divided into two parts

1) The upper respiratory sytem is composed of the nose, sinuses, mouth, pharynx, larynx, and the trachea or windpipe • Ex: Upper RS system toxicant o Hydrogen halids, HCL, HI, HF, HBr o Oxides (NOxm Sox, NaOx) o Hydroxide, (NH4OH, Sodium dust, KOH) 2) The lower respiratory system is composed of the lungs and its smaller structures including bronchi and the alveoli • Ex2: Lower RS toxicants o Monnaes (ac o Halides (fluorine, chlorine, bromine) o Miscellaneous substances (H2S, Phosphers, methylene cynical, silica, soot)

Dose

Amount of toxicant the animal receives

Doses vs. Response distribution curve with standard deviation, mean, see page 44-47

Do it. Example 2.1

Three parameters that play significant roles in various routes of entry

Gastrointestinal tract, the skin, and the respiratory system

2-6 onward for rest of chapter.

Not worthy for Quizlet

Threshold dose

The minimum amount needed for a response to occur. Toxicologists sometime find that a toxicant has a threshold dose. Your Organs can execute some toxicant at low doses but after a certain level become overwhelmed and can no longer resist the toxicant

chronic toxicity

adverse health effect following repeated exposure to a chemical, which can occur following a relatively short exposure, or long term exposure

reproductive toxic

chemical that can affect adult male or female reproductive system, their ability to reproduce and/or that can lead to birth defects

Corrosive

chemical that causes irreversible damage to skin, eyes, or airways

Carcinogen

chemical that causes or can potentially cause cancer

Irritant

chemical that causes reversible damage to skin contact, eyes, or airways

CMR

chemical that is carcinogenic, mutegenic, or toxic to reproductive

Blood counts are also used to determine toxic exposures through _______

measurements of the red and white blood cells, hemoglobin content, and platelet count are performed easily and inexpensively

How toxicants are eliminated from biological organisms

o Detoxification : by changing the chemical into something less harmful by biotransformation o Excretion: through the kidneys, liver, lungs, other organs o Storage: fatty tissues are storage of toxicants

Effects of toxicants on Biological Organisms

o See table 2-2 from books / PPT notes on effects that are irreversible and reversible o To make sure that you are not affected harmfully by toxicants during your employment in a chemical plant you have to do and archive for recorded health data 1) Initial Tests (medical test) 2) Ongoing Tests (medical test)

Respiratory System

plays a significant role in toxicants entering the body through inhalation. Main function of RS is exchange oxygen and carbon dioxide btw the blood and inhaled air. In one minute a normal person at rest uses an estimated 250ml of oxygen and expels approx 200 ml of carbon dioxide

Response

type and magnitude of negative or positive effects the animals shows from the dose o Dose - Response Curve, Response on Y axix

Stratum Cornuum

Outer layer in skin that consists of dead, dried cells that are resistant to penetration by toxicants -most chemicals are not absorbed readily by the skin. A few chemicals however, have remarkable skin permeability.

Acute toxicity

an adverse health effect following a single exposure to a chemical

Skin plays important roles in both dermal absorption and inject routes of entry through

injection includes both entry by absorption through cuts and mechanical injection with hypodermic needles

Four ways chemicals can enter body

1) Ingestion - through the mouth into the stomach 2) Inhalation - through the mouth or nose into the lungs 3) Injection - through cuts into the skin 4) Dermal absorption - through skin membrane Worst for ya - Injection, inhalation, ingestion, dermal

The Spirometer measures 4 things

1) the total volume exhaled, called the forced vital capacity (FVC) in Liters; 2) the forced expired volume measured at one second (FEV1), with units in liters per second 3) forced expiratory flow in the middle range of the vital capacity (FEV 25 - 75%), measured in liters per second; 4) the ratio of the observed FEV1 to FVC x 100 Reduction in FVC are due to reduction in the lung or chest volume, possibly as a result of fibrosis ( an increase in the interstitial fibrous tissue in the lung). The air remaining in the lung after exhalatation is called the residual volume (RV). An increase in the RV is indicative of deterioration of the alveoli, possibly because of emphysema.

If the response of interest is death or lethality, the response versus log dose curve of figure 2-7 is called a ________. Breakdown of LD, ED, TD.

Lethal Dose Curve. Y Axic is response, X axis is the logarithm of the Dose. 1) LD50 dose: lethal dose for 50% of the subjects. Low toxicity means a high LD50. High toxicity means a low Ld50 2) ED50 - If the response to the chemical or agent is minor and reversible (such as minor eye irritation), the response dose curve is called the efffective dose (ED) curve. Low toxicity means high ED50. High toxicity means low ED50; 3) TD: if the response to the agent is toxic (an undesirable response that is not lethal but is irreversible, such as silver lung damage), the response-log dose curve is called the toxic dose or TD curve

Respiratory system problems diagnosed using ______.

Spirometer

Gastrointestinal tract

The GI tract plays the most significant role in toxicants entering the body through ingestion. Food or drink is the usual mechanism of exposure. Airborn particles (either solid or liquid) can also lodge in the mucus of the upper respiratory tract and be swallowed.

Skin disorders diagnosed by ____

changes in skin texture, pigmentation, vascularity, and hair and nail appearance are indicative of possible toxic exposures

mutagen

chemical that can cause permanent damage to genetic materials in cells which can possibly lead to heritable genetic damage or cancer

Acute toxicityy

effect of a single exposure or a series of exposures close together in a short period of time

Chronic toxicity

effect of multiple exposures occurring over a long period of time

Nervous system disorders are diagnosed by _____

examining a patient's mental status, cranial nerve function, motor system reflexes, and sensory systems. An electroencephalogram (EEG) tests higher brain and nervous system functions.

Major objective of toxicological studies is to _____. Before undertaking a toxicological study, the following items must be identified:

quantify the effects of the suspect toxicant on a target organism; 1) the toxicant 2) target or test organism 3) effect or response to be monitored 4) the dose range 5) the period of the test

the rate of selectivity of absorption by the GI tract are highly dependent on many conditions including:

type of chemical, molecular weight, molecule size and shape, acidity, susceptibility to attack by intestinal flora, rate of movement through GI tract

Kidney funnction is determined through _____

variety of tests that measure the chemical content and quantity of urine. For early kidney damage proteins or sugars are found in urine.