Untitled Flashcards Set

Unit 4

Measures of Toxicity
• Lethal Dose (LD50) is the quantity of material that when exposed a
specific way (oral and dermal) is expected to cause the death of 50%
of a defined animal population
• Lethal Concentration (LC50) is the quantity of materials in the air, that
when exposed to over a period of time, is expected to cause the
death of 50% of a defined animal population
• LD50 and LC50 are important criteria used in WHMIS for classifying
Health Hazards

Exposure

Exposure Limits
• Is the maximum allowable amount of exposure to an air contaminant
for workers to avoid adverse health effects
• Threshold Limit Value (TLV) is expressed in a few different ways:
• Time-Weighted Average (TWA) – the concentration in the air that will NOT
affect workers with adverse health effects in a regular 8 hour shift day after
day
• Short-Term Exposure Limit (STEL) – the concentration in the air, when
averaged over a 15 min period, up to a max of 4 times per week that will NOT
affect workers with adverse health effects
• Ceiling Limit – the concentration in air that should never be exceeded, applied
to all chemicals with acute toxic effects

Carcinogenicity

of 23

                     Automatic Zoom                     Actual Size                     Page Fit                     Page Width                                          50%                     75%                     100%                     125%                     150%                     200%                     300%                     400%                   

Course Objectives
14.4 Handle and store biological and chemical materials as per stated
guidelines

Health & Physical Hazards
Let’s look a little more at these two classification that we will have
already seen with WHMIS

Health Hazards
• Health hazards fall under a variety of risks in the lab
• Toxicity
• Lethality
• Carcinogenicity
• Corrosivity
• Allergic reactions
• Reproductive effects
• Neurological effects
• Diseases of the organs
• Can be short term (acute) or long term (chronic)

Measures of Toxicity
• Lethal Dose (LD50) is the quantity of material that when exposed a
specific way (oral and dermal) is expected to cause the death of 50%
of a defined animal population
• Lethal Concentration (LC50) is the quantity of materials in the air, that
when exposed to over a period of time, is expected to cause the
death of 50% of a defined animal population
• LD50 and LC50 are important criteria used in WHMIS for classifying
Health Hazards

Exposure Limits
• Is the maximum allowable amount of exposure to an air contaminant
for workers to avoid adverse health effects
• Threshold Limit Value (TLV) is expressed in a few different ways:
• Time-Weighted Average (TWA) – the concentration in the air that will NOT
affect workers with adverse health effects in a regular 8 hour shift day after
day
• Short-Term Exposure Limit (STEL) – the concentration in the air, when
averaged over a 15 min period, up to a max of 4 times per week that will NOT
affect workers with adverse health effects
• Ceiling Limit – the concentration in air that should never be exceeded, applied
to all chemicals with acute toxic effects

Corrosivity
• A chemical that can damage or destroy other substances when they
come into contact
• Strong acids and strong bases are classified as corrosive substances
• Example: Hydrochloric acid (HCl)
• If the corrosive substance is of low concentration, it will then be
referred to as an irritant

Reproductive Effects & Hazards
• Substances or agents that may affect the reproductive health of
women or men and their ability to have healthy children
• Hazards can be chemical, physical or biological
• Examples: lead (chemical), radiation (physical), viruses (biological)
• Potential health effects include infertility, miscarriage, birth defects
and developmental disorders in children

Physical Hazards
• A term used to capture a variety of hazards including:
• Compressed gas
• Cryogenics
• Electricity
• ionizing radiation
• Temperature extremes
• Noise
• Pressure
• We will go into more detail in a following presentation

General Storage Guidelines for Chemicals
• Ensure good ventilation for chemical storage
• All hazardous chemicals to be stored in a secure location accessible only
to authorized persons
• Minimize what is stored in the lab – store extra in a chemical store room
• Use unbreakable shatter-proof containers when possible
• Do not store glass containers on the floor
• Protect chemicals from heat and from direct sunlight
• Store hazardous materials in cabinets designed to contain spills
• Store larger containers on lower shelves
• Store liquids below eye level

Chemical storage
• Incompatible chemicals must be segregated or kept separated
during storage (see Tables 7.1 and 7.2 in the CSMLS Lab Safety
Guidelines on pp 59 and 60)
• Suggested segregation categories
• Flammables
• Non-flammable solvents
• Acids
• Caustics (bases or alkaline substances)
• Water reactive chemicals
• Oxidizers
• Oxidizing compressed gases
• Non-oxidizing compressed gases
• Non-volatile, non-reactive solids

Flammables
• Store in a flammable cabinet away from oxidizers
• Examples:
• Xylene
• Acetone
• Alcohols

Xylene is flameble agent also and cause carcinogen
• Glacial acetic acid which in its concentrated form as indicated by the word
“glacial” is a flammable with a flash point of 39°C

Substances that burn at room temperature are called "flammable substances" or "combustible materials."

• Flammable substances ignite easily at normal temperatures (below 100°F or 37.8°C). Example: gasoline, alcohol, acetone.

• Combustible materials require higher temperatures to catch fire (above 100°F or 37.8°C). Example: wood, paper, diesel fuel.

Acids
• Store in an acid and corrosive liquid cabinet of non-combustible materials
• Further separate oxidizing acids from organic acids
• Store separate for caustics (bases – also corrosive) and cyanides etc.
• Examples: nitric acid (an oxidizing acid)
• Hydrochloric acid
• Acetic acid (vinegar) (an organic acid)
• Formic acid (an organic acid)
• Sulfosalicylic acid

Caustics (Bases)

Caustics (Bases)
• Store in dry area
• Separate from Acids
• Examples
• Sodium hydroxide
• Potassium hydroxide

Oxidizers

• Store in a non combustible cabinet

• Separate from flammable and combustible materials

• Examples:

• Sodium hypochlorite (bleach)

• peroxides

Compressed gases
• Store in well ventilated area (upright and secured - chained to wall)
• Separate oxidizing and non-oxidizing compressed gasses
• Have valve protection caps securely in place when not attached to a
regulator
• Safely transport using a cylinder cart, do NOT roll
• Examples:
• Oxygen (oxidized compressed gas)
• Carbon dioxide (non-oxidizing compressed gas

The Transportation of Dangerous Goods (TDG) is classified into 9 classes based on the type of hazard they pose.

9 Classes of TDG:

1. Class 1 – Explosives (e.g., fireworks, TNT)

2. Class 2 – Gases (e.g., propane, oxygen, ammonia)

3. Class 3 – Flammable Liquids (e.g., gasoline, alcohol)

4. Class 4 – Flammable Solids (e.g., matches, sodium)

5. Class 5 – Oxidizing Substances & Organic Peroxides (e.g., hydrogen peroxide, ammonium nitrate)

6. Class 6 – Toxic & Infectious Substances (e.g., cyanide, medical waste)

7. Class 7 – Radioactive Materials (e.g., uranium, medical isotopes)

8. Class 8 – Corrosive Substances (e.g., acids, bleach)

9. Class 9 – Miscellaneous Dangerous Goods (e.g., dry ice, lithium batteries)

These classifications help ensure the safe handling, transportation, and storage of hazardous materials. 🚛💥

Reactive Material
• May be unstable
• Store somewhere away from heat and light
• Minimize jarring or moving
• Example:
• Picric Acid (dry) – ensure it does not dry out while in storage
• Benzoyl peroxide

Non-volatile, non-reactive solids
• Store in cabinets or open shelves with edge guards
• Examples:
• Agar powders
• Sodium chloride (table salt)
• Sodium bicarbonate (baking soda)

Axgard is commonly used in chemical storage areas as a protective material. Its main functions include:

1. Safety Shielding: Axgard is an impact-resistant plastic (often polycarbonate) used to create barriers or shields to protect workers from splashes, spills, or explosions.

2. Chemical Resistance: It is resistant to many chemicals, making it suitable for use in environments where corrosive or hazardous substances are stored.

3. Transparent Protection: Since Axgard is clear, it allows visibility while maintaining protection, useful for viewing chemical labels and monitoring stored substances.

4. Durability: It is stronger than glass, shatterproof, and withstands harsh conditions, reducing risks in chemical storage areas.

Would you like specific details on its chemical resistance or applications? 😊

UNIT 4  PART 2                                                                                                                                       

Physical Hazards
• A term used to capture a variety of hazards including:
• Compressed gas
• Cryogenics
• Electricity
• Temperature extremes
• Noise
• Pressure
• Ionizing radiation

Compressed Gases
• Can explode if heated or damaged
• Breakage of the valve or rupture of the cylinder can cause it to become a
rocket or fragmentation bomb
• Can displace air at a high rate and produce an oxygen deficient atmosphere
• Can also be toxic, flammable, or corrosive in nature
• Secured firmly in upright position
• Do not secure with nylon or other combustibles
• In area separate from lab unless cylinder in use

Compressed Gas Storage
• Keep incompatible gases separate
whether full or empty
• Store with safety valve cap not
with regulator
• Mark or tag when empty
• Promptly return empty canisters

Compressed Gas Transport
• Secured with racks, chains or stands – upright
• With appropriate carts or dollies
• Do NOT roll or drag
• Transport with valve safety in place not with regulator

Cryogenics
• Cryogenic fluids are liquified gases at very low temperatures (approx.
below -73.3°C)
• Can present both physical and chemical hazards based on
characteristics of material
• Most commonly used in the lab is liquid nitrogen
• Hazards include: cold temperatures, high pressure, burns and tissue
damage
• Controls include: appropriate PPE (face protection and insulated
gloves)

Electricity
• Has the potential to cause bodily harm when comes in contact
• Can be an ignition source
• Can burn tissue along pathway of current flow
• Can cause ventricular fibrillation or be fatal
• Risk and severity of damage depends on voltage and duration on
contact
• Inspect electrical cords and equipment regularly and contact facility
maintenance for any electrical work

Temperature
• Temperature extremes are hazardous as they interfere with the
body’s ability to regulate
• Increased temps lead to burns/hyperthermia
• Decreased temps lead to burns/hypothermia
• Ensure you know and follow all proper procedures
• Wear insulated gloves when working with extreme cold or hot
material

Noise
• Defined as unwanted sounds
• Exposure to certain levels of noise can result in poor communication,
hear loss, tinnitus, disruption of sleep and/or relaxation
• In clinical labs, noise rarely reaches levels where the above occurs
• Hearing protection can be provided if this is an issue

Pressure
• Pressure changes can lead to shattering of lab equipment (i.e., glass)
or splashes from solutions into eyes and on skin
• Can be due to rapid temperature changes like removing items from
the autoclave
• Always follow your lab’s SOPs and the manufacturers
recommendations
• Allow heated or cooled items to return to room temperature
• Wear eye and face protection

Radiation Hazard and
Spill Clean-up

Ionizing Radiation Definition

• Radiation that has enough energy to displace an electron from an

atom or a molecule , thereby producing ions

Sources of Ionizing Radiation
• X-rays
• Gamma rays
• Alpha particles
• Beta particles
• Neutrons

External vs. Internal Exposures
External:
• Relevant to forms of radiation
that can penetrate deeply
into the human body:
primarily x-rays and gamma
rays

Internal:
• Relevant to when nuclear
substances are inhaled or
ingested
• Absorbed through skin, eyes,
cuts and abrasions
• Primarily alpha particles, beta
particles, and gamma emitters

Acute vs. Chronic Effects
Acute:
• Large dose over a short time
• Disorders of
• Skin
• Bone marrow
• Digestive system
• Neuromuscular system
Chronic:
• Appearing years after exposure
• Leukemia
• Other malignancies

Greatest Risk from Radiation
• Bone marrow and other blood forming tissues
• Breast
• Thyroid
• Lungs
• Digestive system
• Fetus

How to Minimize Exposure
• Know the materials you are working with and their requirements for
shielding
• Use the appropriate shielding materials and PPEs for the appropriate
types of radiation to prevent secondary radiation emissions
• Lead
• Plexiglass
• Gloves
• Use shielded storage

How to Minimize Exposure
• Maximize distance between radiation sources and people
• Demarcate “hot” work areas and label them clearly using signs and
tape etc.
• Post radiation warning signs on the doors of rooms where radioactive
materials are either used or stored
• Practice techniques without radioactive materials – the more
proficient one is the less time they will be exposed

Radiological Hazard Spill (CSMLS)
1. Evacuate the lab if hazardous aerosols are present.
2. Allow the ventilation system to purge the area of hazardous aerosols.
3. Obtain survey equipment and ensure dosimetry is being conducted,
as required.
4. Obtain decontaminants suitable for the spilled material and employ
the decontamination step after removal of adsorbent.
5. Follow procedures for confirming removal of radiological
contaminants using wipe tests

Non-ionizing Radiation
• Refers to the types of radiation that does not carry sufficient energy
to ionize atoms or molecules
• Three types of non-ionizing radiation found in the lab
• Lasers (barcode readers)
• Microwaves (common in lunchrooms)
• UV radiation (common in BSCs)
• Minimize exposure by:
• Not looking directly into a laser
• Perform regular maintenance of the microwave
• Close the sash when UV light is on and it should never be on while in use

Psychological Hazards

Definition – Psychological Hazards
• Result from the factors in the work environment, management and
organizational practices that affect employees
• Can affect both physical and mental health
• Ensuring control of these types of hazards reduces employee
absence, turnover and incidents

Examples
• Harassment, abuse and bullying in the workplace
• Working alone
• Lack of job security
• Increased workload and/or hours of work
• Noise, lighting
• Age related issues
• Health and medical status
• Work/life balance and/or conflict

Ways to Avoid or Reduce
• Having policies and procedures to identify, report and investigate
these types of hazards (incident reports)
• Management communication when change is occurring
• Feedback provided – positive and constructive
• Support systems for the employees (health and wellness, assistance
programs, etc.)
• Better scheduling and workload distribution

Working Alone
• This is defined as when a working cannot be seen or heard by another
person
• Occurs more with smaller/remote labs and usually on off-shifts
(evenings, nights, weekends)
• Labs need policies for working alone and assess when it not
appropriate
• A check-in and check-out procedure may be necessary, as well as a
means of emergency communication for assistance

Spill Response Procedure

A spill response is a set of actions taken to safely manage and clean up hazardous material spills. The response depends on the type and severity of the spill.

Steps for Spill Response:

1. Assess the Situation

   • Identify the spilled substance (chemical, biological, or radioactive).

   • Determine the spill size (small, medium, or large).

   • Check for immediate dangers (fire, fumes, injuries).

2. Ensure Personal Safety

   • Wear appropriate Personal Protective Equipment (PPE) (gloves, goggles, respirator, etc.).

   • Evacuate the area if necessary.

3. Contain the Spill

   • Use spill containment materials (absorbents, barriers, or dikes).

   • Stop the source of the spill if safe to do so.

4. Clean Up the Spill

   • Use spill kits (pads, absorbents, neutralizers).

   • Follow chemical-specific cleanup procedures.

   • Dispose of contaminated materials properly (hazardous waste disposal).

5. Decontaminate the Area

   • Wash surfaces with appropriate cleaning agents.

   • Ventilate the area to remove fumes or vapors.

6. Report and Document

   • Notify the supervisor or safety officer.

   • Complete an incident report for future prevention.

Emergency Actions for Specific Spills:

• Flammable Liquids: Turn off ignition sources and ventilate the area.

• Acids/Bases: Use neutralizing agents before cleanup.

• Biological Spills: Disinfect with appropriate solutions.

• Radioactive Spills: Follow radiation safety protocols and notify specialists.

Would you like a spill response checklist for laboratory use? 😊

Generic Spill Response Procedure

A generic spill response applies to most types of spills, including chemicals, biological materials, and other hazardous substances. It follows a structured approach to ensure safety and minimize risks.

1. Assess the Spill

• Identify the substance spilled (chemical, biological, etc.).

• Determine the spill size (small, medium, or large).

• Check for immediate hazards (fire, fumes, injuries).

• Decide if you can safely handle it or need emergency assistance.

2. Ensure Personal Safety

• Alert others in the area.

• Wear appropriate PPE (gloves, goggles, respirator, lab coat, etc.).

• Evacuate if needed, especially for toxic or flammable spills.

• Turn off ignition sources if dealing with flammable substances.

3. Contain the Spill

• Prevent spreading by using absorbent materials (spill pads, sand, absorbent booms).

• Block drains to avoid contamination of water systems.

• Stop the source of the spill if safe to do so.

4. Clean Up the Spill

• Use appropriate spill kits or cleaning materials.

• For chemical spills: Neutralize acids or bases if applicable.

• For biological spills: Disinfect with a suitable disinfectant.

• For radioactive spills: Follow radiation safety protocols.

• Collect and dispose of waste properly (hazardous waste disposal).

5. Decontaminate & Ventilate

• Clean all affected surfaces thoroughly.

• Remove and dispose of contaminated PPE properly.

• Increase airflow if fumes or vapors are present.

6. Report & Document

• Notify the safety officer or supervisor.

• Fill out an incident report for future prevention.

• Review the incident to improve spill response protocols.

Would you like a specific spill response guide for laboratory settings? 😊

Specific Spill Response Procedures

Spill response procedures vary depending on the type of hazardous material involved. Below are detailed response steps for different types of spills:

1. Chemical Spill Response

Small Chemical Spills (low hazard, manageable size)

✔ Wear appropriate Personal Protective Equipment (PPE) (gloves, goggles, lab coat).
✔ Contain the spill with absorbent materials (spill pads, sand, or vermiculite).
✔ Clean up using appropriate neutralizers (e.g., sodium bicarbonate for acids, citric acid for bases).
✔ Dispose of waste in hazardous waste containers.
✔ Ventilate the area if fumes are present.

Large or Highly Hazardous Chemical Spills

🚨 Evacuate and alert emergency responders (safety officer, hazardous materials team).
🚨 Turn off ignition sources if the chemical is flammable.
🚨 Do not attempt cleanup if the chemical is toxic, highly reactive, or unknown.
🚨 Close off the area and prevent entry.

2. Flammable Liquid Spill Response

✔ Remove ignition sources (flames, sparks, electrical equipment).
✔ Use spill pillows or absorbent pads to contain the liquid.
✔ Avoid using materials that can generate static electricity.
✔ Clean with non-sparking tools and properly dispose of waste.
🚨 For large spills, evacuate and notify emergency personnel.

3. Acid & Base Spill Response

✔ Acid Spills: Neutralize with sodium bicarbonate (baking soda) before cleanup.
✔ Base Spills: Neutralize with citric acid or vinegar before cleanup.
✔ Absorb the neutralized liquid with spill pads and dispose of properly.
🚨 For concentrated acids like hydrofluoric acid, seek emergency help immediately.

4. Biological Spill Response (Bacteria, Viruses, Blood, Body Fluids)

✔ Wear gloves, lab coat, face shield/mask.
✔ Cover the spill with absorbent materials (paper towels or absorbent pads).
✔ Apply disinfectant (e.g., 10% bleach solution or hospital-grade disinfectant) and let it sit for 10–30 minutes.
✔ Wipe up and dispose of materials in biohazard waste bags.
🚨 For airborne pathogens, evacuate and use biohazard cleanup procedures.

5. Radioactive Spill Response

✔ Notify radiation safety personnel immediately.
✔ Limit the spread by confining the spill with absorbent materials.
✔ Shield the area if the radioactive material emits significant radiation.
✔ Decontaminate the area using approved radiation decontamination agents.
🚨 For large spills or exposure, evacuate and follow radiation safety protocols.

6. Mercury Spill Response (Toxic Metal Spill)

✔ Do not vacuum! Mercury vapors are toxic.
✔ Use a mercury spill kit (specially designed for mercury cleanup).
✔ Collect droplets using a mercury absorbent or suction device.
✔ Store collected mercury in a sealed, labeled container for hazardous waste disposal.
🚨 For large mercury spills, evacuate and contact hazardous materials personnel.

Final Steps for All Spill Types:

✅ Decontaminate the area thoroughly.
✅ Dispose of waste properly (hazardous, biohazard, or radioactive waste bins).
✅ Report the incident to the safety officer.
✅ Review safety protocols to prevent future spills.

Would you like me to create a printable spill response checklist for your studies? 😊

Specific Biological Spill Response Procedures

Biological spills involve bacteria, viruses, blood, body fluids, and other biohazardous materials. Proper response is crucial to prevent infection and contamination.

1. Assess the Spill

✔ Identify the type of biological material (e.g., blood, bacterial culture, viral sample).
✔ Determine if the spill is inside or outside a biosafety cabinet (BSC).
✔ Check for broken glass or sharps that may require special handling.
✔ If the spill is airborne (e.g., tuberculosis, COVID-19), evacuate immediately and allow aerosols to settle for 30 minutes before re-entering.

2. Ensure Personal Safety

✔ Wear Personal Protective Equipment (PPE):

• Gloves (double gloves for highly infectious spills)

• Lab coat or gown

• Face shield or goggles

• N95 respirator (if airborne risk)

✔ Restrict access to the area – prevent others from entering.

3. Contain & Disinfect the Spill

A. Liquid Biological Spill (Blood, Body Fluids, Cultures)

✔ Cover the spill with absorbent materials (paper towels, spill pads).
✔ Pour disinfectant (10% bleach or hospital-grade disinfectant) around the spill first, then on top.
✔ Let the disinfectant sit for 10–30 minutes to inactivate the biological agent.

B. Dry Biological Spill (Dried Blood, Powdered Contaminants)

✔ Lightly mist the spill with disinfectant to prevent aerosolization.
✔ Cover with paper towels and apply more disinfectant.

C. Spill Inside a Biosafety Cabinet (BSC)

✔ Keep the cabinet running to contain aerosols.
✔ Disinfect all surfaces with appropriate disinfectant.
✔ If needed, remove and disinfect equipment.

4. Clean Up & Disposal

✔ Wipe up the spill from the edges toward the center to prevent spreading.
✔ Dispose of all contaminated materials in biohazard waste bags.
✔ If sharps (e.g., needles, broken glass) are present, use tongs or a sharps container—never pick up with hands.
✔ Mop the area with fresh disinfectant solution.

5. Report & Decontaminate

✔ Remove and dispose of PPE properly (gloves last).
✔ Wash hands and exposed skin with soap and water.
✔ Report the spill to the safety officer or lab supervisor.
✔ If exposure occurred (e.g., splash to eyes, cut on the skin), seek medical attention immediately.

Special Considerations:

🚨 For large spills or airborne pathogens (e.g., tuberculosis, anthrax, COVID-19):

• Evacuate immediately and allow aerosols to settle before cleanup.

• Notify biosafety officers or emergency responders.

🚨 For highly infectious agents (e.g., Ebola, HIV, Hepatitis B):

• Use higher-level PPE (e.g., full-body suit).

• Follow CDC or WHO biosafety protocols.

Would you like a printable checklist for biological spill response? 😊

 Part  3

Spill Response
• Spills can range from minor to major
• Spill response kits/equipment are stored in the laboratory with easy
access
• Individuals dealing with any spill must be properly trained in spill
response procedures and use the correct equipment
• Best practice is to place a copy of the spill response procedure and
the spill kit contents with the kit itself

What is Adsorption?

Adsorption is a surface phenomenon where atoms, ions, or molecules from a gas, liquid, or dissolved solid accumulate on the surface of a solid or liquid. This occurs due to attractive forces between the surface and the substance being adsorbed.

Key Features of Adsorption:

✔ Happens on the surface (unlike absorption, which occurs throughout the material).
✔ Reversible or irreversible process depending on the type of interaction.
✔ Common in chemical, biological, and industrial processes (e.g., water purification, gas masks, drug delivery).

Types of Adsorption:

1. Physical Adsorption (Physisorption)

   • Weak van der Waals forces hold molecules on the surface.

   • Low energy requirement.

   • Reversible (e.g., adsorption of gases on activated charcoal).

2. Chemical Adsorption (Chemisorption)

   • Strong chemical bonds form between the surface and adsorbed molecules.

   • Higher energy requirement.

   • Often irreversible (e.g., rust formation on iron).

Examples of Adsorption:

✔ Activated charcoal adsorbs toxins in water filtration.
✔ Silica gel adsorbs moisture in packaging.
✔ Catalysts in industrial reactions (e.g., platinum in catalytic converters).
✔ Gas masks use adsorption to trap harmful gases.

Would you like a comparison between adsorption and absorption? 😊

if specimen collect by specific procedure , in case specimen likage we use 70% alcohol and hydrogen per oxide