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SAFE HANDLING &

USE OF CHEMICALS

Chemical Form (States of Matter)

Particulate contaminants.

Fumes.

Mists.

Dusts & fibers.

Gases and vapors.

Particulate Contaminants

Fumes. Formed by condensation of volatilized

solid in cool air.

Formed by welding, torch cutting,

brazing, etc.

Usually, less than 1.0 µm diameter.

In most cases, hot vapor reacts with

air to form oxide.

Particulate Contaminants

Mists

Suspended liquid droplets generated by:

» condensation of liquids from vapor back to liquid state, or

» breaking up liquid into dispersed state (splashing or

atomizing).

Term “mist” is applied to finely divided liquid

suspended in atmosphere.

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Particulate Contaminants Dusts

Generated by handling, crushing, grinding, impact,

detonation, and decrepitation (breaking apart by

heating).

Term used to describe airborne solid particles that

range from 0.1 - 25 µm.

Fibers

Similar generation.

Similar particle size but range in length from 6-12 mm.

Hazardous Particulates

50 mm

100 mm

Selected Hazardous Particulates

Asbestos. Asbestosis, cancer.

Beryllium. Berylliosis, cancer.

Bacteria. Humidifier fever.

Cotton dust. Byssinosis.

Be

Chrysotile Asbestos

20 mm

1 mm

Selected Hazardous Particulates

Diesel exhaust. Lung cancer.

Lead & compounds. CNS, PNS, blood.

Nickel. Nasal cancer, allergic contact dermatitis.

Pesticides. CNS, cancer.

Cadmium, chromium, cobalt, manganese. Cancer, CNS, pneumoconiosis.

Lead ore

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Gases and Vapors

Gas is a fluid in the gaseous state having neither

independent shape or volume.

Vapor refers to a gas-phase material that

normally exists as a liquid or solid under a given

set of conditions.

How to handle chemicals properly

Use cautions

Always follow procedures

Read all labels

Keep yourself and the work area clean

Plan ahead

Routes of Exposure

Inhalation. Through the lungs.

Ingestion.

Swallowed.

Absorption

Through the skin or eyes.

Injection.

Needle stick.

Inhalation

Chemicals in the air are inhaled into the body

through the mouth or nose.

In the workplace, airborne chemicals may occur in

different forms such as gases, vapors, dusts or mists.

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Ingestion

Ingestion can occur through eating or smoking

with contaminated hands or in contaminated

work areas.

Absorption

Skin contact with chemicals can result in

irritation, allergic response, chemical burns, and

allergic contact dermatitis.

Physically damaged skin or skin damaged from

chemical irritation or sensitization will generally

absorb chemicals at a much greater rate than

intact skin.

Injection

Chemical substances can be injected into the

body by accidentally puncturing the skin with a

contaminated needle or other sharp device.

Symptoms of Possible Overexposure

Eye discomfort

Breathing difficulty

Dizziness

Headache

Nausea

Vomiting

Skin irritation

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Incompatible Chemicals

Flammables and oxidizers

Flammables and any ignition source

Acids and cyanides

Strong acids and strong alkalines

Concentrated acids and water

Organic solvents and corrosives

Corrosives and other reactive materials

Chemical Manipulation

Be familiar with chemical properties and products of

chemical reactions.

Be prepared for chemical spills and clean up spills

immediately.

Plan ahead – have apparatus and associated

equipment ready before chemicals are used.

Use the appropriate equipment, such as funnels,

beakers and spatulas when transferring chemicals.

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Chemical Manipulation

Use chemical fume hoods to control exposure as chemicals are transferred.

Use chemical fume hoods to control exposure during the experiment. Wear the appropriate personal protective equipment

(chemical splash goggles, gloves, etc.). Have disposal containers ready ahead of time.

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Recommended Practices

Examine your currently available work area

Avoid floor

clutter

• Avoid

shelf/bench

clutter

Consider inexpensive storage

containers for small or loose items. Arrange containers based on compatibility

• Use durable waterproof labels and markers to clearly indicate what is in the container.

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Your chemical storage area is not a kitchen—no food storage please!

• Sturdy shelving units with edging to prevent containers from falling off.

• Food jars are designed to hold food. Store hazardous lab chemicals only in containers designed to hold them.

Acids should be

stored in an Acid

Cabinet

• Flammables should be stored in a Flammables Cabinet

Chemicals should be stored in compatible groups. Oxidizers should never be stored with flammables, acids should never be stored with bases, and toxics should be stored by themselves. Chemicals from different groups that are still compatible can be stored together.

Acids and bases must be stored separately in chemical resistant secondary containers to prevent the spread of corrosives should a spill occur.

Hazardous chemicals (particularly corrosives) should never be stored above the shoulder height of the shortest person in lab. When necessary, only non-hazardous chemicals should be stored on upper shelves.

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All chemicals must be properly labeled as to the contents. Any labels that are illegible or have fallen off should be replaced.

Secondary chemicals containers should be labeled with the contents and the date on which the reagent was made. Labels that are loose or illegible should be replaced. All containers (including those that just hold water) must be labeled as to their contents.

Many chemicals such as anhydrous (diethyl) ether, tetrahydrofuran, and 1,4-dioxane readily form potentially explosive peroxides. These chemicals must not be stored in the lab beyond the recommended period.

The most dangerous peroxide forming chemicals are potassium metal, isopropyl ether, sodium amide, and potassium amide. These chemicals must not be stored in lab for longer than three months.

Flammable liquids should be stored in a flammables cabinet.

Keep containers closed when not in use

Keep away from ignition sources

Avoid contact with incompatible materials

Only transfer to approved containers

Up to ?? Liters of flammable liquids may be stored in the lab outside of the flammable cabinet.

Spark sources such as variacs and power strips must be stored outside of any fume hood where flammable solvents are employed.

Flammable liquids as well as other chemicals and wastes must not be stored on the floor in glass containers due to the potential for breakage.

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Gas cylinders must be securely anchored individually. They should also have a status label that indicates if the cylinder is full, empty, or in use. The practice of using a single chain to anchor several cylinders is dangerous and unacceptable.

Gases such as carbon monoxide, chlorine, fluorine, phosgene, hydrogen fluoride, nitric oxide, sulfur dioxide, and hydrogen sulfide must be kept in a continuously ventilated mechanical enclosure such as a fume hood.

Excess cylinders should be stored in an approved storage area outside of the lab. Flammable gases must be stored at least 20 feet away from oxygen and oxidizing gases.

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Safety Equipment

Make particular note of the locations of:

Emergency telephone numbers. Eyewash fountains Emergency showers First Aid Kit Spill kits. Fire Extinguisher Emergency exits and evacuation routes.

ASK YOURSELF!!!

•Do I know where they are located? •Do I know how to use? •Do I know that they work? •Are they accessible?

Safety Equipment

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Each lab should have a first aid kit that is properly stocked.

FMA 1967: what items are or are not needed for the first aid kit.

A hydrofluoric acid treatment kit should be included if you use HF in your laboratory.

All laboratories where flammables are stored or used must have a fire extinguisher. Special Class D extinguishers should be kept in all labs that use reactive metals such as sodium, potassium, or magnesium.

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Safety Equipment

Emergency eyewash station and safety showers are required within 10-seconds travel distance and not more than 75 feet from where hazardous chemicals are used.

- must be on the same level as the chemical area; - there can be no stairs or ramps between the hazard and the eyewash and/or safety shower.

Inspect safety showers and eye washes yearly.

The location of each safety shower and eye wash should be clearly posted.

The area around showers and eye washes must be left unobstructed.

Laboratory personnel should inspect eyewashes weekly.

Safety Equipment

Fire Extinguishers Only attempt to fight a fire with a portable fire extinguisher if...

• You are trained to use portable fire extinguishers • The fire is small and contained, not big or rapidly spreading • The extinguisher is approved to fight the specific type of fire

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Classified according to the types of fire they are designed to extinguish: Type A – Used only on fires of ΄combustible΄ materials, such as wood, paper, and similar materials Type B – Used on organic liquid and other highly flammable materials Type C – Used on fires of electrical origin Type D – Used on highly reactive metals or metal compound

Types of Fire Extinguishers

All laboratories that employ hazardous chemicals must have a chemical spill kit that is capable of handling any spill in lab.

Laboratories that use large volumes of acids, caustics, or solvents may need to keep specialized spill control materials on hand.

Emergency Procedures

Emergency Procedures which is required for emergency situations.

Used to inform you of the procedures to follow in the event of an emergency.

Know how to respond to an emergency

In case of emergency………….. - know how to respond - require rapid building evacuation - know the alternate exit routes - know the location of assembly point

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Personal Hygiene

Wash your hands after you complete the lab (even if you have been wearing gloves ): - to limit your exposure to any chemicals you have handled in the workplace .

You should also wash your hands before leaving the workplace for any reason, even if you intend to return

within a few minutes

Do not eat, drink or apply makeup in workplace

Here are some key points to keep in mind: • Keep work and walking surfaces clean, dry, and uncluttered. • Make sure you have clear access to stairways andhallways, exits, emergency equipment at all times.

Safe Work Practices

“A place for everything and everything in its place” • L -- Label everything clearly

• A -- Appropriate containers in good condition

• B -- Be neat and orderly • S -- Store only what you will use • A -- Always wear protective clothing • F -- Food allowed in eating areas only • E -- Everything in its place on a shelf • T -- Time to inventory & organize • Y -- Your safety is important

Recognizing Chemical Exposures

Recognize.

Common chemicals.

Operations where used.

SDS.

Evaluate.

Control.

Evaluating Chemical Exposures

Recognize.

Evaluate.

Chemical form.

Routes of exposure.

# employees exposed.

Level(s) of exposure.

Permissible exposure limit (PEL)

Control.

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Critical Factors

Determining exposure. Chemical composition.

Crystalline, structural, & isotopic forms of particles.

Shape of particles.

Size of particles.

Dose: concentration vs. duration.

Pre-existing health or genetic status.

Concurrent exposure to other toxic agents.

Staph Infection Bacteria

Chemical Composition

Chemical composition can be primary concern. Lead, cadmium, silica, smoke composition, radiological

particles, etc.

Biological organisms. Type and numbers.

TB Bacteria

Smoke

from the

twin

towers

Silica dust. “free crystalline silica”.

• Diatomaceous earth.

• Fumed silica.

• Silica gel.

Smokes, soots, organic origin.

Radioisotopes.

Crystalline, Structural, Isotopic Nature Particulate Size Determination

Workers are not exposed to single particles but rather to large masses of particles suspended in air (particle clouds).

Particle clouds may be:

Monodisperse. » Composed of airborne particulates with a single size or a small

range of sizes. » e.g. fog from boiling acid; welding fumes.

Polydisperse. » Composed of airborne particulates of many different sizes. » e.g. sand blasting; paint spraying.

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Particle Size Terminology

Micrometer (µm). A unit of length equal to one

millionth of a meter. Also known as “micron.” Equal to

1/25, 400th of an inch.

Non-respirable. Particles > 10 µm in diameter.

Deposited in respiratory system before reach alveolar

sacs in lungs.

Respirable. Particles < 10 µm in diameter. Likely to

reach alveolar sacs in great quantities.

Air Sampling & Analysis

Sampling for particulates is a fundamental

activity by Industrial Hygienists (IH).

Determine exposure vs PEL/TLV.

Breathing zone sampling.

Personal. » Sampling pump and cassette attached to worker.

Air Sampling & Analysis

Area sampling.

Area where workers are located. » Sampling pump and cassette placed in area.

» New instantaneous instruments to measure total,

PM10 and PM2.5.

Microbiological sampling is generally area

sampling using plates or impingers.

Air Sampling

Size selective particle sampling on

filters for either gravimetric or

microscope counting of fibers. Respirable dust is collected on a filter

(37 mm) using a cyclone set up. » Gravimetric analysis.

Asbestos is collected on smaller filter. 25 mm.

Cyclone filter

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Why Measure?

Personal protection.

Personal compliance monitoring.

TWA.

STEL or ceiling.

Area monitoring.

Confined space entry.

Hazardous spill.

What Gases/Vapors Do I Want to Measure?

Gases or vapors measured limit the sensing

technology used.

Range will also limit sensing technology used.

Magellan ammonia pipeline rupture in

Kingman Co., Kansas on Oct. 27, 2004.

Gases and Vapors: Sampling Methods

Grab sampling. Detector tubes.

Gas bags.

Passive dosimetry. “Film badges”.

Active sampling. Sorbent tubes & personal

sampling pump.

Direct reading instruments.

Gas Bags (Grab bags)

Theory – samples are collected

via a slow-flow sample pump

and stored in a plastic or foil

bag.

A wide variety of gases can be

measured.

Advantages – Easy sample

storage. A variety of bag

materials adds to the unit’s

versatility.

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Detector Tubes

Theory - glass tubes filled

with reagent that changes

color in reaction to certain

chemicals.

Gases measured - Wide

variety of gases can be

measured.

Advantages - Can measure

many gases that cannot be

measured by direct-reading

instruments.

Passive Sampling

Definition: the collection of airborne

gases and vapors at a rate controlled

by a physical process such as

diffusion through a static air layer or

permeation through a membrane

without the active movement of air

through an air sampler.

Diffusion of contaminated molecules

from an area of high concentration to

an area of low concentration on the

sampler

Passive Dosimeters

Partial list of substances for which badges are

available:

Mercury (Hg).

Nitrous oxide (N2O).

Ethylene oxide (C2H4O).

Formaldehyde (CH2O).

Other organic substances.

Sorbent Tubes

Common sorbent materials are: Activated charcoal. Silica gel. Tenax. XAD-2. Chromosorbs.

Sorbent used to collect specific

chemicals will be specified in the sampling method.

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Workplace Chemical Exposures

Recognize.

Evaluate.

Control.

Engineering.

Administrative.

PPE.

Controls

Engineering controls.

Enclosing or confining operation or worker.

Ventilation:

» General, i.e. Dilution Ventilation

» Local Exhaust Ventilation

General Ventilation for University Labs

ASHRAE HVAC Handbook: Laboratories

Minimum airflow rates are generally in the range of 6 to 10

air changes per hour when the space is occupied

Minimum ventilation rates at the lower end of the 6 to 12

ach range may not be appropriate for all laboratories.

Minimum ventilation rates should be established on a

room-by-room basis considering the hazard level of

materials expected to be used in the room and the

operation and procedures to be performed. As the

operation, materials, and hazard level of a room change,

an increase or decrease in the minimum ventilation rate

should be evaluated.

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Local Exhaust Ventilation

A peer reviewed article presented the results of analyzing over 1.5

million hours of lab operation from 18 different sites and over 300 lab

spaces. The results showed that the number of actionable chemical and

particulate contaminant events that required more than the minimum

dilution airflow was in the range of only 1 to 2 % of the time.

Controls

Administrative controls.

Work practice controls

» Alter manner in which task is performed

Job rotation*

Training

Task timing

Controls Personal protective equipment

Equipment that creates a barrier against workplace

hazards.

Must provide employee training.

Continuous program assessment.

Controls Personal protective equipment Program

The employer shall establish and implement

procedures on:

Issuance

Maintenance

Inspection

Training

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Employers Preventing Illnesses

What can employers do to prevent illness?

Comply with OSHA regulations.

Reduce exposure levels through the use of engineering

controls.

Provide appropriate respiratory protection while these

controls are being installed, or if they are being

repaired.

Perform air monitoring of worksites as needed, and

when required by law, and take corrective action when

levels are excessive.

What can employees do to prevent illnesses?

Inform themselves of the hazards and what precautions

to take.

Comply with workplace rules.

Reduce exposure levels through the use of engineering

and administrative controls.

Use appropriate respiratory protection and other PPE

properly.

Employees Preventing Illnesses