SAFE HANDLING & USE OF CHEMICALS · 2018-05-16 · 1 SAFE HANDLING & USE OF CHEMICALS Chemical Form...
Transcript of SAFE HANDLING & USE OF CHEMICALS · 2018-05-16 · 1 SAFE HANDLING & USE OF CHEMICALS Chemical Form...
1
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.
2
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
3
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.
4
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
5
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.
19
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.
20
6
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.
7
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.
8
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.
9
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.
Page 35
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
10
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.
Page 38
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
11
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
12
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.
13
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.
14
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
15
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.
16
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.
17
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.
18
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
19
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