CHEM 25 SAFETY QUIZ

Accident Prevention

-a collective responsibility that requires the full cooperation of everyone in the lab

-EVERYONE is responsible for accident prevention

RESULTS FROM:

-indifferent attitude

-failure to use common sense

-failure to follow instructions, making a mistake

-FOLLOW THE GENERAL GUIDELINES

Eye Protection

-EVERYONE, including visitors, must wear chemical splash goggles (not safety glasses or prescription: even if they meet the US food and drug administration standards for impact resistance)

-even when there's no chemical operations happening

-Contact lenses: don't give enough protection in place where accident chemical splash can be expected

Clothing

-should offer protection from splashes and spills; easily removable in case of an accident (at least fire-resistant)

-If you wear a lab jacket/coat: should have snap fastener rather than buttons so it's easily removed

-Closed-toed shoes made of leather (nothing woven)

-No shorts/skirts/dresses or anything that would expose your skin (potential corrosives)

-tie hair up

-don't wear jewelry (it'll get ruined and can have a corrosive impact; can also catch on things causing accidents)

Gloves

-important for personal protection

-Different types: latex, neoprene, butyl rubber, etc

-although cloth or leather gloves may protect against hot/cold objects, don't rely on them for protection against hazardous chemicals

-> (cloth) they're porous; (leather) contaminated from prior use

-no glove material can provide permanent protection

-->If a chemical diffuses through a glove: it is then held against your skin - you could get more exposure than if you hadn't worn a glove at all (dispose of contaminated gloves)

Lab Protocol

Variations in procedures: include changes in chemicals to be used or in the amounts to be used = may be dangerous

-ask the instructor before you make changes (with his knowledge and approval)

Lab Visitors

-No matter what, they must wear eye protection

-Get instructor's approval before bringing visitors into the lab

Cleaning Glassware

-clean soiled glassware at the lab sink or in lab dishwashers

-use only environmentally acceptable cleaning agents (ex: soap, detergent)

-Don't use strong cleaning agents: nitric acid, chromic acid, sulfuric acid, or other strong oxidizers; or flammable solvents unless instructed to do so

Inhaling Harmful Chemicals

Some people think that if they can smell a chemical. it's causing them harm -> not necessarily correct

-Correct: if you smell a chemical, you're inhaling it

-Some have odor, but cannot be detected by the human nose at harmful concentrations

-Some, even though they might have a noxious odor, are not harmful if inhaled

-BASICALLY: the presence of an odor isn't a reliable indication of potential harm and the absence of an odor is not a reliable indication of the absence of harm

-Many substances may or may not have an odor are harmful if their vapors, dust, or mist are inhaled

Distillation

Common method of separation and purification used in lab and industrial operation

Refrigerators

-chemicals should be placed on a spill tray with edges high enough to contain any spilled contents

-always seal, double-package, label, date

-dispose of any old chemicals

-don't store food or beverages

Disposal

-instructor will typically tell you where to dispose of certain chemicals/wastes

-never put down the sink/drain unless the instructor has told you to do so

-the regular waste paper is not to be thrown with wastes

-broken glass in its own container

Toxicity

Factors that take effect:

-the dose

-route of exposure

myriad other factors such as gender, stage in the reproductive cycle, age, lifestyle, allergic factors, etc

-The toxic effects can be immediate or delayed, reversible or irreversible, local or systemic

Inhalation

through the respiratory tract (lungs) by breathing

Ingestion

through the digestive tract

-through eating; chewing gum; makeup; smoking in lab; etc

absorption

through body openings: eyes, eyeball sockets, cuts in skin, even through intact skin

Injection

-> of a toxic substance through a cut made in the skin by a sharp, contaminated object

-mishandling a sharp-edged piece of a contaminated glass beaker, knife, needle, etc

Acute Poisoning

-the rapid assimilation of the substance

-often, the effect is sudden and can be painful or severe and even fatal

-single exposure

-ex) carbon monoxide, cyanide poisoning

Chronic poisoning

-repeated exposures with a duration measured in months, or years

-symptoms not immediately apparent

-ex) lead, mercury, pesticide exposure

substances in combo

-may result in a synergist (combo of 2 substances that have a greater effect than one substance alone) effect

-alcohol and chlorinated solvents

-the opposite is also possible

-> 2 poisonous substances can lessen each other's effects: the antagonistic effect

-> ex) cyanide and amyl nitrite

Allergens

-agents that produce an immunologic reaction

-asthma-like symptoms or dermatitis

-not everyone is susceptible

Exposure Limits

Toxic chemicals can cause harm if they're ingested

-until you've washed your hands don't touch yourself at all

-some toxic chemicals can be absorbed directly through intact skin (wear gloves for these chemicals!) -> wash hands thoroughly

-If you spill a chemical on your skin/clothing, wash it off immediately and thoroughly

US Occupational safety and Health Administration (OSHA)

-hazardous chemical: any chemical that presents a hazard either under normal use or in a future emergency

-MSDS for hazardous chemicals describes its hazards and the precautions you must take to avoid harm

CAS registry number

ACS Chemical Abstracts Service (CAS): assigns a number to each chemical

Ceiling Limit

-some very hazardous chemicals are characterized by a ceiling limit and a permissible exposure limit (PEL) or a threshold limit value (TLV)

-concentration in parts per million or milligrams per cubic meter

Chemical name

IUPAC (int. union of pure and applied chem) or CAS chemical name given

-trade/common name for chemical may be given instead

Composition of Mixtures

-all hazardous components present in concentrations greater than 1%

-all carcinogens in concentrations greater than 0.1%

Flash Point

the lowest temperature at which the vapor of a chemical can be ignited by a flame when it is slowly heated in a special apparatus

Autoignition

the lowest temperature at which a chemical ignites spontaneously in the air

Flammable limits

all flammable chemicals have a minimum and max vapor concentrations in air below and above which they cannot be ignited

Permissible Exposure Limit (PEL)

the concentration of a hazardous chemical in the air expressed in units of ppm (parts per million) or mg/m^3 (milligrams per cubic meter)

Short-term exposure limit (STEL)

the concentration in ppm or mg/m3 that should not be exceeded for more than a short period

-usually 15 minutes

PEL

permissible exposure limit

TLV

threshold limit value

Time-weighted avg (TWA)

orker exposures must be measured and averaged over an 8-hour day

Threshold limit value (TLV)

a concentration limit

-similar to PEL but by ACGIH instead of OSHA

-legal limit = more reliable

Danger

the hazards can cause serious injury (i.e. blindness, loss of limb) or death

Warning

the hazards can cause less than serious injuries

Caution

warns users to be careful when using, handling, or storing the chemical

LOOK AT THE COMMON WORDS USED IN MSDSS AND LABELS

Combustible

ignites under usual working conditions

Flammable

can readily ignite under usual working conditions

extremely flammable

very readily ignites under usual working conditions

Lachrymator

irritant/burning effect on the eyes and is dangerous in very small quantities

-only open in lab hood

Mutagen

causes damage to chromosomes

Oxidizer

oxidizes an substance that can oxidize (any substance that can burn)

Poison

Has very serious and often irreversible toxic effects on the body

-may lead to death

-avoid all contact

Pyrophoric

catches fire spontaneously upon exposure to air

Reproductive Hazard

tetrogen or mutagen

Teratogen

causes birth defects and/or fetal death

-can affect fetal development

Sensitizer

can cause an allergic reaction on a 2nd, 3rd, or later exposure

Skin

can absorb toxic substances directly through intact skin and have toxic effects

Toxic

Hazardous when inhaled, swallowed, injected, or in contact with skin

organic solvents can...

-penetrate intact skin

-cause dryness and cracking

-vapors = toxic

-dizziness, slurred speech, unconsciousness and (rarely) death

Halogens

-all halogens are toxic oxidizing agents

-especially flourine

Strong Bases

-all corrosive

-can cause serious, destructive chemical burns and serious blindness

Formaldehyde

Colorless, water-soluble, pungent, and irritating gas

Lab Hoods

-control exposures to toxic, offensive, or flammable vapors

-protect from implosions, but not from explosions

-requires airflow and the absence of excessive turbulence

-keep the sash closed, or open it only the minimum amount necessary

-keep face outside the plane of the hood sash

-do work within the hood (at least 15 cm/6 in) from the front edge of the fume hood -> far back in the hood as practical, but don't block the rear vent openings

-don't dispose of hazardous waste/evaporating solvents

Before you help another person...

evaluate the potential danger to yourself

-if you try to help and are injured, you can't be of much further help to someone else

Fires

-the best way to fight fires is to prevent it

-a fire contained in a small vessel often can be suffocated via wet cloth/another method (NOT cloth or towel)

-it's easy to underestimate a fire: never use a fire extinguisher unless you're trained to use it

Personal Injuries Involving Fires

-when a person's clothing is on fire, lead them to the safety showers

-stop an individual from running

-if no shower: douse in water; stop drop and roll; lie down and roll to put out fire

-beat out flames from head to feet

-then cover with blanket or coat, but keep the head uncovered

-Don't use the fire blankets until the fire is extinguished

Chemicals on skin, clothing, and eyes

-For small liquid spills that only affect a small area of skin, immediately flush with flowing water for at least 15 minutes.

SOLID chemicals spilled onto skin

Can usually be brushed off with no adverse consequences (put into proper waste)

-> if solid adheres to your skin call your instructor

Larger Spills of Liquid

-Larger consequences

-go to the safety shower immediately

-take off all contaminated clothes (cut sweaters/shirts off with scissors)

-at least 15 minutes

Splashes in the eye

-flush with temperate potable water fro source for at least 15 minutes

-hold eyelids away from eyeball and move eyes continuously

Other personal Injury accidents

-anyone overcome with smoke: to fresh air and treated for shock

-In ingested something: follow first aid in label or MSDS; never give CPR UNLESS the person is not breathing

-severe bleeding: compress wound with a cloth or whatever is available

-> elevate injury above the heart

Spill Cleanup

-if flammable is spilled: everyone should extinguish all fires; to turn off spark-producing equipment such as brush-type motors, and leave the area

-try to contain spills on floors and benches only

-Many small liquid spills on the floor or laboratory bench (e.g., less than 200 mL) can be absorbed with paper towels, sand, or special absorbent

-Use a dustpan and brush, and wear protective gloves to clean up dry spills and liq- uid spills that have been absorbed by an absorbent