Phar Cal Lab: Quiz 1 (GHS and Lab Hazards)

Laboratory work

A critical component of all chemistry programs and related sciences, beginning with introductory-level undergraduate classes

Recognize hazards, Assess the risks of hazards, Minimize the risks of hazards, Prepare for emergencies

RAMP

Globally Harmonized System of Classification and Labelling of Chemicals

GHS

Hazard

something that causes harm ( ex. chemicals, equipment, procedures, etc.)

Risk

The probability that a hazard causes harm

Severity of hazard and likelihood of exposure

Two components of risk

Recognize Hazards

Students should be able not only to recognize common laboratory hazards but also to explain why these are hazards

Chemical hazards, physical hazards, health hazards, and reaction hazards

Common laboratory hazards

Corrosive chemicals

Typically strong acids and bases, solutions with a pH < 2 or a pH > 12, and some solvents, such as formic acid, glacial acetic acid, and trifluoroacetic acid, which are particularly aggressive against tissue

Flammable chemicals

Chemicals that are easily ignited or explode under usual laboratory working conditions, such as low-molecular-weight alcohols, aldehydes, ketones, and hydrocarbons

Incompatible chemicals for storage or handling

Storing strong oxidizers, such as nitric acid, with reduced compounds, such as hydrocarbons. Reactants that react with air or water, such as alkyl metals or acid halides.

Compressed gases and high-pressure systems

Includes both the chemical hazard of the gases and the physical hazard of all parts of the system subjected to greater than 1 bar (>100 kPa)

Low-pressure and vacuum systems

Includes any system that operates at less than 1 bar (<100 kPa), including rotary evaporators

Electrical hazards

All electrical equipment and energy sources

Radiation hazards

Both ionizing and non-ionizing radiation, including lasers and ultraviolet lamps

Cryogenic hazards

Any system operating below 0⁰C. Examples are dry ice (solid CO₂), liquid nitrogen, liquid oxygen, liquid hydrogen, and liquid helium.

Cryogenic hazards

Any system operating at greater than 90.1 K (the boiling point of O₂) will condense oxygen and create a potentially highly flammable environment

Toxic substance classifications

Students should be able to explain terms such as "highly toxic," "acutely toxic," "chronically toxic," carcinogens, allergens, mutagens, and teratogens

Acute

Short exposure

Chronic

Prolonged exposure

Catalyst

Speeds up the reaction

Carcinogenic

Can cause cancer

Teratogenic

Can cause harm to the fetus

Thalidomide

A chemical that causes deformities to the unborn child, which caused a tragedy in the past

Skin and eyes, inhalation, and mouth

Three main routes of hazards

Acute chemical exposures

Students should recognize that brief exposures to highly toxic or allergenic chemicals that have a significant impact on health, and should be able to identify chemicals with these properties. Biological chemicals can also have significant effects, such as biological enzymes that can produce allergic reactions. 

Chronic chemical exposures

Students should recognize extended exposure to chronically toxic chemicals can result in cancer or other organ-specific damage, and should be able to identify such compounds

Nanomaterials

The small size of nanomaterials allows these materials to enter deeply into the respiratory tract or to penetrate unprotected skin. Currently, there is very limited information about the health impact of these materials, so strict handling precautions are required.

Scale-up and potential runaway reactions

During a research career, the need to synthesize larger quantities of a specific chemical is likely. This scale-up may alter reaction kinetics unpredictably and may create conditions under which a reaction vessel can self-heat more than passive cooling can dissipate away, creating a thermal runaway reaction.

Catalyst effects on reactions

Whenever a catalyst is added to a reaction, the reaction rate changes as does the rate of generation of heat and byproducts. Separating some catalysts from reaction mixtures may cause fires. 

Reactive and unstable chemicals

Students should be able to explain what makes chemicals reactive or unstable, including both explosive chemicals and reactions that could lead to explosions. Pyrophoric chemicals require special techniques for handling, and students must be trained specifically in these techniques if they are to use these chemicals. Chemicals that react with air or water, such as phosphorous oxychloride (POCl₃), sodium metal (Na), or acetic anhydride, require special handling to address their reactive hazards. Also included are chemicals that become unstable over time, such as cyclic polyenes or some alkyne structures.

Peroxides and peroxide-forming chemicals

Students should be able to explain peroxide activity and the types of chemicals that form peroxides spontaneously at varying rates. Most —C–O–C— compounds that contain an activated α-hydrogen will slowly react to form the corresponding peroxide —C–O–O–C—, which may be violently unstable.

Agent, condition, and activity

Three types of hazards

Agent

Carcinogenic, teratogenic, sensitizing agent, corrosive, pyrophoric, toxic, mutagenic, reproductive hazard, explosive, non-ionizing radiation, biological hazard/pathogenic flammable, oxidizing, self-reactive or unstable, potentially explosive, reducing, water-reactive, sensitizing, peroxide-forming, catalytic, or chemical asphyxiant

Condition

High pressure, low pressure, electrical, uneven surfaces, pinch points, suspended weight, hot surfaces, extreme cold, steam, noise, clutter, magnetic fields, simple asphyxiant, oxygen-deficient spaces, ultraviolet radiation, or laser light

Activity

Creation of secondary products, lifting, chemical mixing, long-term use of dry boxes, repetitive pipetting, scale-up, handling waste, transportation of hazardous materials, handling glassware and other sharp objects, heating chemicals, recrystallizations, extractions, or centrifuging

Engineering controls, Administrative controls, and PPE

Three ways to minimize the risks of hazards

First degree burns

Characterized by redness or discoloration of the skin, mild swelling and pain

At least 10 minutes

How long is the immersing period for first degree burns?

Second degree burns

Characterized by red or scarred skin with blisters

Third degree burns

Characterized by white or charred skin

At least 15 minutes

How long is the immersing period for chemical burns on the skin and eyes?

Water - 1% acetic acid - water

First aid for alkali spill on skin

N-95 mask

The type of mask for noxious gases

Silver sulfadiazine

The scientific term for the available ointment in the laboratory

Material Safety Data Sheet

A list containing information about the proper storage and handling of chemicals