study guide

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 Basic components of LEV

 Hood/ intake

 Ducts

 Air cleaner

 Fan

 Exhaust

 Types of air cleaners

 Filters

 Wet collectors

 Centrifugal collectors

 Electrostatic precipitators

 Settling chambers

 Adsorbers

 Types of fans

 Centrifugal

 Axial

 Measurements for LEV evaluation

 Face velocity  Q = VA

 Pitot traverse  V = 4005 x VP

 Dilution ventilation

 Qdil = 387 x pounds x 10

6 x K

mix MW x t x Ca x d

 Mixing factor

EHST 3700/3701:

Industrial Hygiene

 To identify the major anatomical components

of the skin

 To describe the function and limitations of

the skin in providing protection against

hazardous agents

 To describe different types of skin responses

to hazardous agents

 To enumerate occupations or activities that

pose skin injury due to hazards

 To list control measures for the prevention of

occupational skin injuries

 Function and anatomy of the skin

 Causes of occupational skin injuries

 Preventing occupational skin damage

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 Provides physical barrier between internal

organs and outside agents

 Retains moisture

 Shields from damaging radiation

 Serves as an organ of sensory perception

 Keratin layer

 Basal layer

 Phenolic compounds

 Germicidal cleaners

 Metalworking fluids

 Paints

 Plastic resins

 Interference with melanin production

 Destruction of melanin-containing cells

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 Contains connective tissue that supports the

skin (corium)

 Contains blood vessels, nerves, hair follicles,

muscles, oil and sweat glands

 Contains fatty and connective tissue

 Provides cushion and insulative base for the

skin

 Binds the skin to underlying tissues that

cover organs, muscles and bones

1. Physical condition of the skin

2. Environmental conditions under which

exposure occurs

3. Amount of moisture present or relative

dryness of skin

4. Amount of pigmentation present in the skin

5. Body location where material contacts the

skin

6. Age and gender of the worker

7. Pre-existing damage or allergies

8. Personal hygiene habits of the worker

 Mechanical damage

 Physical damage

 Temperature extremes

 Ionizing and non-ionizing radiation

 Chemical damage

 Solvents

 Acids/ bases

 Biological agents

 Bacteria

 Fungi

 Parasites

 Botanical agents

 Friction resulting to blisters

 Skin abrasion due to contact with rough

surfaces

 Physical skin damage from sharp objects

 Burns due to extreme heat

 Frostbite due to extreme cold

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 Allergic contact dermatitis

 Irritant contact dermatitis

 Chloracne

 Hyperpigmentation

 Ulcerative lesions

 Erythema

 Produced only after repeated exposure and

only in some individuals

 Characterized by redness, swelling and

cracking of the exposed skin

 May involve systemic responses (i.e.

difficulty breathing, airway inflammation,

pulmonary edema)

 Phenols, epoxies,

rubbers, acrylics,

nickel compounds,

plant resins

Exposure to phenol-formaldehyde resins Photo source: www.cdc.gov/niosh

 Localized symptoms caused by exposure to

chemicals

 Solvents (degreasing)

 Acids and bases

Exposure to ethylene oxide (a powerful skin irritant)

Photo source: www.cdc.gov/niosh

 Skin irritation that resembles adolescent acne

 Caused by halogenated compounds (with

chlorine, bromine and iodine)

 Occupational acne

Chloracne

 Acne-like eruptions on

exposed skin caused by oily

or greasy compounds

 Top causes: water-insoluble

cutting oils, creosote, tar

Photo source: www.cdc.gov/niosh

 Darkening of skin due to stimulation of

melanin production

 Caused by tars, arsenic compounds, and

plant sensitizers

Arsenic Hyperpigmentation

 Chrome holes associated with exposure to

hexavalent chromium (Cr6+)

Chrome hole on finger

Chrome hole on nasal septum

Photo source: www.cdc.gov/niosh

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Chemical Class/ Name Layer Affected Response

Inorganic and organic

acids

Epidermis (keratin

layer)

Contact irritation;

chemical burns

Alkaline solutions Epidermis (keratin

layer)

Contact irritation;

blisters, drying and

cracking of skin

Petroleum products; coal

tar materials

Epidermis (keratin

layer)

Dermis (hair follicles)

Contact irritation

Metals or metal salts of

mercury, arsenic,

chrome, nickel, zinc

Epidermis (keratin

layer)

Dermis (hair follicles)

Skin ulcers; acne;

spotty pigmentation;

sensitizers, skin cancer

Metalworking fluids

(cutting oils and

coolants)

Dermis (hair follicles)

Epidermis

(melanocytes)

Oil acne; loss of

pigment

Resins/coatings and

adhesives (epoxies,

shellacs, vinyls,

acrylates, isocyanates)

Epidermis (keratin

layer)

Dermatitis; loss of

pigment

 Outdoor occupations

 Construction work

 Road building

 Roofing

 Landscaping

 Forestry

Photoallergic Reaction Involving Sunlight

 Sunburn

 Skin cancer

 Phototoxic reaction

 Localized areas of tenderness or pain at exposed

location

 Photoallergic reaction

 Involves the immune system

 Bacteria

 Fungi

 Insects

 Parasites

 Plants

 Animals

 Immediate reaction on the skin

 Swelling, reddening and sometimes small

fluid-containing eruptions

 Result of an allergic reaction to the proteins

in the secretion of the plant or animal

Contact urticaria from exposure to natural latex rubber

 Febrile illness associated with a tick-borne

bacteria, Borrelia burgdorferi

 Most commonly reported vector-borne

disease in the U.S.

 First sign: small red circle resembling a bull’s

eye that develop at the bite site

 Symptoms: fever, aches, headache, nausea,

vomiting; heart affected

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 Caused by the bacteria, Bacillus anthracis

 Lives in the hair of sheep and other animals

 Lives in soil for a number of years

 Workers at risk: handlers of imported wool

and animals hides

 Bacteria enters the body through a cut on

the skin or at a mucous membrane 

localized infection and sore

Poison oak Stinging nettle

Poison sumac

 Contact dermatitis

 Inflammation of the skin caused by direct

contact with an irritating substance

 Caused by a chemical called urushiol, which

produces an itchy rash, redness, blisters and

scaling

Workers at Risk Biological Agent Condition

Animal care workers,

breeders, veterinarians,

farm workers

a. Tinia unguium and

Tinia corporis

b. Candida candidiasis

a. Ringworm

b. Yeast infection

Dishwashers, bartenders,

other performing wet

work with their hands

Candida candidiasis Yeast infections primarily

around fingernails

Tannery workers Bacillus anthracis Cutaneous anthrax

Granary workers, grocers,

personnel who

handle/transport foods

a. Parasitic mites

b. Ticks

a. Itching, dermatitis

b. Itching, swelling,

secondary infections

Construction workers,

masonry workers

Hookworm larvae Possible subsequent

infestation of the intestinal

tract

Hikers, campers, outdoor

occupations

a. Poison oak and ivy

b. Snake bites

c. Ticks

a. Contact dermatitis

b. System reactions

c. Lyme disease, Rocky

Mountain spotted fever

 Skin provides a protective barrier between

our bodies and the environment.

 Skin is composed of the epidermis, dermis

and subcutaneous layers.

 The response of the skin to hazardous

depends on several factors: physical

condition of skin  personal hygiene.

 Mechanisms of skin damage involve physical

damage, chemical damage, damage from UV

radiation and biological agents.

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 Occupational skin disorders include:

 Irritant contact dermatitis

 Allergic contact dermatitis

 Loss of pigmentation

 Hyperpigmentation

 Occupational acne

 Chrome holes

 Phototoxic response

 Photoallergic response

 Cutaneous anthrax

 Fungal and yeast infections

Chemical agents

UV radiation

Biological agents