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National Fire Protection Association (NFPA) Signage and Labeling

• The National Fire Protection Association (NFPA) developed a standard hazard identification system utilizing a diamond-shaped, color-coded symbol to communicate risks in clinical laboratories.

• The diamond is divided into four quadrants, each representing a specific hazard type:

  • Blue Quadrant: Health hazards.

  • Red Quadrant: Flammable hazards.

  • Yellow Quadrant: Reactivity/stability hazards.

  • White Quadrant: Special information (specific hazards).

• Each quadrant displays a numerical magnitude of severity, graded on a scale from a low of $0$ to a high of $4$.

Health Hazard (Blue) Severity Levels

• $4$: Deadly.

• $3$: Extreme danger.

• $2$: Hazardous.

• $1$: Slightly hazardous.

• $0$: Normal material.

Fire Hazard (Red) Flash Point Thresholds

• $4$: Below $73^{\circ}F$.

• $3$: Below $100^{\circ}F$.

• $2$: Above $100^{\circ}F$, not exceeding $200^{\circ}F$.

• $1$: Above $200^{\circ}F$.

• $0$: Will not burn.

Instability/Reactivity (Yellow) Severity Levels

• $4$: May detonate.

• $3$: Shock and heat may detonate.

• $2$: Violent chemical change.

• $1$: Unstable if heated.

• $0$: Stable.

Specific Hazard (White) Designations

• ACID: Acid.

• ALK: Alkali.

• COR: Corrosive.

• OXY: Oxidizer.

• P: Polymerization.

• ☢ (Symbol): Radioactive.

• W (with strikeout): Use no water.

Presidential Decree No. 856 and Waste Disposal

• Code of Sanitation of the Philippines: This decree mandates the Department of Health (DOH) to promote and preserve public health and upgrade medical practice standards.

• Color-Coding for Waste Disposal: The decree introduced a standardized system for waste container bags based on the type of waste:

  • Black: Non-infectious waste.

  • Green: Non-infectious wet waste.

  • Yellow: Infectious and pathological wastes.

  • Yellow with Black Band: Chemical wastes, including heavy metals.

  • Orange: Radioactive waste.

  • Red: Sharps and pressurized containers.

Clinical Laboratory Safety Responsibilities

Employer's Responsibilities

• Establish laboratory work methods and safety policies.

• Provide supervision and guidance to employees.

• Provide safety information, training, Personal Protective Equipment (PPE), and medical surveillance to employees.

• Provide and maintain equipment and laboratory facilities that are free of recognized hazards and adequate for required tasks.

Employee's Responsibilities

• Know and comply with established laboratory safe work practices.

• Maintain a positive attitude toward supervisors, co-workers, facilities, and safety training.

• Be alert and provide prompt notification of unsafe conditions or practices to the immediate supervisor.

• Ensure that unsafe conditions and practices are corrected.

• Engage in the conduct of safe work practices and the use of PPE.

Precautionary Labeling and Documentation

Chemical Manufacturer Labels

• Manufacturers provide precautionary labeling that must include:

  • Statement of the hazard.

  • Precautionary measures.

  • Specific hazard class.

  • First aid instructions for internal/external contact.

  • Storage code.

  • Safety code.

  • Personal protective gear and equipment needed.

• Example: Isopropyl Alcohol (CAS #67-63-0) displays a Health rating of $2$, Flammability rating of $3$, and Reactivity rating of $0$.

Safety Data Sheets (SDS)

• The SDS is a major source of safety information for employees. It must include requirements for:

  • Product name and identification.

  • Hazardous ingredients.

  • Permissible exposure limit (PEL).

  • Physical and chemical data.

  • Health hazard data and carcinogenic potential.

  • Primary routes of entry.

  • Fire and explosion hazards.

  • Reactivity data.

  • Spill and disposal procedures.

  • PPE recommendations.

  • Handling instructions.

  • Emergency and first aid procedures.

  • Storage and transportation precautions.

  • Chemical manufacturer's name, address, and telephone number.

  • Special information section.

Laboratory Safety Infrastructure and Equipment

Engineering Controls

• Fume Hoods: Required to contain and expel noxious and hazardous fumes from chemical reagents.

  • The hood should never be operated with the sash fully opened.

  • A maximum operating sash height must be established and conspicuously marked.

  • Personal air monitoring should be conducted according to the facility's chemical hygiene plan.

• Biological Safety Cabinets (BSCs): Designed to remove particles harmful to employees working with potentially infectious biologic specimens.

  • BSCs offer various levels of protection based on the laboratory's biosafety level.

  • They require periodic recertification to ensure optimal performance; filter occlusion or rupture compromises effectiveness.

  • HEPA-filtered air and contaminated air flow through specific patterns (positive/negative pressure) to protect the worker.

Emergency Equipment

• Safety Showers: Recommended to deliver $30$ to $50\,\text{gallons}$ of water per minute at $20$ to $50\,\text{pounds per square inch (psi)}$. They must be located in areas where corrosive liquids are stored.

• Eyewash Stations: Must be accessible within $100\,\text{feet}$ or $10\,\text{seconds}$ of travel in areas presenting chemical or biological exposure hazards.

• Other Mandatory Items: Fire extinguishers (periodically tested), fire blankets, spill kits, and first aid supplies.

Operational Safety

• Mechanical Pipetting Devices: Must be used for manipulating all types of liquids, including water.

• Mouth Pipetting: Strictly prohibited in all laboratory settings.

Chemical Storage and Handling

• Safety Carriers: Always used for transporting glass bottles of acids, alkalis, or organic solvents in volumes larger than $500\,\text{mL}$.

• Safety Cans: Approved safety cans are required for storing, dispensing, or disposing of flammables in volumes greater than $1\,\text{quart}$.

• Storage Cabinets: Steel safety cabinets with self-closing doors are required for flammable liquids.

• Refrigeration: Only specially designed, explosion-proof refrigerators may be used to store flammable materials.

• Gas Cylinders: Supports or clamps must be used at all times. Larger cylinders must be transported with valve caps on using handcarts.

Personal Protective Equipment (PPE) and Personal Hygiene

PPE Specifics

• Eye Protection: Safety glasses, goggles, visors, or work shields. Contact lenses are strongly discouraged unless additional protective eyewear is used.

• Hands and Arms: Gloves and rubberized sleeves protect against caustic chemicals. Gloves are required for routine use.

• Body Protection: Full-length, buttoned laboratory coats with knit-cuffed sleeves made of liquid-resistant material. Supplement with impermeable aprons/sleeve garters for splash hazards.

• Footwear: Porous materials, open-toed shoes, and sandals are prohibited.

• Respiratory Protection: High-efficiency particulate air (HEPA) filter respirators are required when engineering controls are insufficient, particularly when working with Tuberculosis (TB) specimens.

Proper Handwashing Procedure

1. Wet hands with water.

2. Apply enough soap to cover all hand surfaces.

3. Rub hands palm to palm.

4. Right palm over left dorsum with interlaced fingers and vice versa.

5. Palm to palm with fingers interlaced.

6. Backs of fingers to opposing palms with fingers interlocked.

7. Rotational rubbing of left thumb clasped in right palm and vice versa.

8. Rotational rubbing, backwards and forwards with clasped fingers of right hand in left palm and vice versa.

9. Rinse hands with water.

10. Dry thoroughly with a single-use towel.

11. Use towel to turn off the faucet.

Biological Safety and Pathogen Control

Biologic Precautions

• Centrifugation: Produces finely dispersed aerosols. Specimens must remain capped during centrifugation or for several minutes afterward. Sealed-cup centrifuges are the preferred option.

• Standard/Universal Precautions: All blood, body fluids, and unfixed tissues must be handled as though they are potentially infectious (e.g., HBV, HCV, HIV).

  • Applicable materials: blood, semen, vaginal secretions, CSF, synovial fluid, pleural fluid, body fluids with visible blood, unidentified fluids, unfixed slides, microhematocrit clay, and saliva from dental procedures.

Pathogen-Specific Plans

• Exposure Control Plan: A written plan for bloodborne pathogens must be discussed with all employees at the initial assignment and annually thereafter.

• Airborne Pathogens (TB): Requires ventilation controls in isolation areas. Respiratory protection must be N-95 (filtration of $95\%$ of particles >0.3\,\mu m) or better.

Biological Spill Clean-up Procedure

1. Alert others in the area.

2. Wear appropriate PPE.

3. Use mechanical devices to pick up broken glass/sharps.

4. Absorb the spill with paper towels/gauze/tissue.

5. Clean the site with common aqueous detergent.

6. Disinfect with $10\%$ bleach or approved disinfectant (observe appropriate contact time).

7. Rinse the site with water.

8. Dispose of all materials in appropriate biohazard containers.

Chemical Hazard Categories and Toxicology

• Toxic Substances: Can cause acute (short-term/single contact) or chronic (long-term/prolonged contact) effects. Entry is via absorption, inhalation, ingestion, or inoculation/injection.

  • Personnel must be aware of toxic vapors (e.g., acetone, chloroform, methanol, carbon tetrachloride) that lack sensory irritation warnings.

• Flammable/Combustible Chemicals: Classified by flash point. Combustible liquids have a flash point at or above $37.8^{\circ}C$ ($100^{\circ}F$).

• Corrosive Chemicals: Injurious to tissues; require immediate flushing with water upon contact. Examples: Acetic, sulfuric, nitric, and hydrochloric acids; potassium and sodium hydroxide bases.

• Reactive Chemicals: Can spontaneously explode, ignite, or evolve heat/gas. Exothermic reactions occur when strong acids or bases react with water.

• Carcinogens: Cancer-causing agents, such as Benzidine. Inventories must be maintained, and substitutes used where possible.

Radiation and Fire Safety

Radiation Safety

• Ionizing Radiation: Restricted traffic and caution signs required. Monitoring records must be kept for the length of employment plus $30\,\text{years}$. A Nuclear Regulatory Commission (NRC) license is required for high levels.

• Nonionizing Radiation Types:

  • Low frequency (>1\,\text{cm}): Radiofrequency coils in mass spectrometers.

  • Microwaves ($3\,\text{m} - 3\,\text{mm}$): Used in histology staining.

  • Infrared ($750\,\text{nm} - 0.3\,\text{cm}$): Heat lamps, lasers.

  • Visible spectrum ($400 - 750\,\text{nm}$): General illumination.

  • Ultraviolet ($4 - 400\,\text{nm}$): Germicidal lamps in BSCs (requires eye/skin protection).

Fire Classes and Response

• Class A: Ordinary combustibles (wood, paper, plastic).

• Class B: Flammable liquids/gases and petroleum products.

• Class C: Energized electrical equipment.

• Class D: Combustible/reactive metals (magnesium, sodium, potassium).

• Extinguisher Operation (PASS):

  • Pull pin.

  • Aim nozzle.

  • Squeeze trigger.

  • Sweep nozzle.

Physical and Mechanical Hazards

Electrical and Compressed Gas Safety

• Electrical: Use grounded ($3$-prong) plugs. Never operate with wet hands. Do not work on "live" equipment.

• Compressed Gas: Store tanks vertically and secured. Never store flammable liquids and compressed gases together. Use hand trucks for transport.

Cryogenic and Mechanical Safety

• Cryogenics (e.g., Liquid Nitrogen): Can cause tissue damage similar to thermal burns. Use loosely fitting, impermeable gloves and insert specimens slowly into coolant.

• Mechanical Safety: Centrifuges must be balanced. Use boiling chips to prevent "bumping" when heating liquids.

• Ergonomics: Repetitive physical actions can lead to tenosynovitis, bursitis, or ganglion cysts. Lift heavy objects using leg muscles rather than the back.