9.2 Hazard Communication (HazCom), Safety Data Sheets (SDS) & Chemical Safety

Hazard Communication (HazCom), Safety Data Sheets (SDS) & Chemical Safety

Quick Answer: The OSHA Hazard Communication Standard (29 CFR 1910.1200), commonly called the "Employee Right-to-Know Law," requires dental employers to inform and train employees regarding chemical hazards in the workplace. Aligned with the Globally Harmonized System (GHS), the standard mandates a written HazCom program, an up-to-date master chemical inventory list, readily accessible standardized 16-section Safety Data Sheets (SDS), proper primary and secondary container labeling (including signal words "DANGER" and "WARNING"), the 9 GHS pictograms, and emergency eye wash stations meeting ANSI Z358.1 standards.

Dental assistants handle a diverse range of chemical agents daily, including glutaraldehyde, acrylic monomers, phosphoric acid etchants, gypsum products, surface disinfectants, and nitrous oxide. Mastering chemical safety, exposure limits, and hazard response is vital for the DANB NELDA Infection Control Exam (ICE).

---

1. The Five Pillars of a Dental HazCom Program

OSHA requires every dental practice using hazardous chemicals to maintain a comprehensive Hazard Communication program built upon five core components:

                    FIVE PILLARS OF OSHA HAZCOM COMPLIANCE
   _________________________________________________________________________
  |  1. Written HazCom Program     --> Detailed office chemical safety plan |
  |  2. Master Chemical Inventory  --> Comprehensive list of all chemicals  |
  |  3. Safety Data Sheets (SDS)   --> Standardized 16-section documentation|
  |  4. Chemical Container Labels  --> Primary & secondary GHS labeling     |
  |  5. Employee Safety Training   --> Initial, annual & new hazard training|
  |_________________________________________________________________________|

1. Written Hazard Communication Program:
   • A documented, facility-specific manual explaining how chemical labels, SDS access, chemical inventories, and employee training are managed in the office.
   • Details safe handling procedures for non-routine chemical tasks (e.g., cleaning mercury amalgam spills or changing chemical sterilant baths).
2. Master Chemical Inventory List:
   • A complete, cataloged list of every hazardous substance present in the dental practice (e.g., bonding resins, dental stone, impression materials, cold sterilants, ultrasonic detergents).
   • Must be updated immediately whenever a new chemical product is introduced to the office.
3. Safety Data Sheets (SDS):
   • Standardized 16-section reference documents provided by chemical manufacturers detailing physical/health hazards, handling instructions, and emergency procedures.
   • Must be readily accessible to all workers in the clinical area at all times without restrictions (e.g., physical binders or unobstructed digital software).
4. Chemical Container Labeling:
   • All primary containers from manufacturers and secondary containers filled in the office must carry compliant GHS labels indicating the chemical identity and specific physical and health hazards.
5. Employee Training and Education:
   • Required upon initial hire/assignment, whenever a new chemical hazard is introduced into the clinical workplace, and documented in office safety records.

---

2. Safety Data Sheets (SDS): The 16-Section Standardized Format

Under GHS alignment, the old 9-section Material Safety Data Sheet (MSDS) was replaced by the standardized 16-Section Safety Data Sheet (SDS). Sections 1 through 8 focus on quick-access emergency, health, and handling information, while Sections 9 through 16 detail technical, toxicological, and regulatory data:

---

3. GHS Container Labeling & Standardized Pictograms

All chemical containers in the dental office must comply with OSHA GHS labeling requirements:

                  GHS STANDARDIZED CHEMICAL CONTAINER LABEL
   _________________________________________________________________________
  |  [Product Identifier / Chemical Name] (e.g., ISOPROPYL ALCOHOL 70%)     |
  |                                                                         |
  |  [SIGNAL WORD]  -->  DANGER  (or WARNING)                               |
  |                                                                         |
  |  [GHS PICTOGRAMS]                                                       |
  |    🔥 (Flame - Flammable)         ⚠️ (Exclamation - Irritant)          |
  |                                                                         |
  |  [HAZARD STATEMENTS]                                                    |
  |  • Highly flammable liquid and vapor.                                   |
  |  • Causes serious eye irritation. May cause drowsiness or dizziness.   |
  |                                                                         |
  |  [PRECAUTIONARY STATEMENTS]                                             |
  |  • Keep away from heat, sparks, open flames. Ground container.         |
  |  • Wear protective gloves and eye protection. Wash hands thoroughly.    |
  |                                                                         |
  |  [SUPPLIER IDENTIFICATION]                                              |
  |  Dental Supply Corp | 123 Healthcare Way | Emergency: (800) 555-0199   |
  |_________________________________________________________________________|

Primary vs. Secondary Container Labeling Rules

• Primary Containers: The original container shipped by the chemical manufacturer. It must always retain its intact GHS label.
• Secondary Containers: Any container into which a chemical is transferred from the primary container (e.g., dispensing surface disinfectant into a spray bottle, pouring ultrasonic cleaning solution into a holding jar, placing alcohol into a dispenser).
  • The Secondary Container Rule: Secondary containers MUST be labeled with the product identifier and specific physical/health hazard warnings (words, pictures, symbols).
  • The Immediate Use Exemption: A secondary container does NOT require a label ONLY IF:
    1. The chemical is transferred by the employee who will use it,
    2. The chemical is under the constant direct control of that employee, AND
    3. The chemical is used up completely during that single work shift.
    • Clinical Caution: If the container is left unattended, stored for the next shift, or used by any other team member, it must carry a full secondary label immediately.

GHS Signal Words

Under GHS, only two standardized signal words exist:

1. "DANGER": Used for more severe hazard categories (e.g., high flammability, corrosive destruction, acute systemic toxicity).
2. "WARNING": Used for less severe hazard categories (e.g., mild skin irritation, moderate eye irritant).

The 9 Standard GHS Pictograms

---

4. High-Hazard Chemicals in Dental Practice & Handling Standards

1. Glutaraldehyde and Ortho-phthalaldehyde (OPA)

• Use: High-level disinfectants / chemical liquid sterilants for heat-sensitive instruments.
• Hazards: Potent chemical sensitizers, toxic vapors causing severe eye irritation, rhinitis, occupational asthma, and contact dermatitis.
• Safety Protocol: Must be kept in a tightly covered immersion tray; used in dedicated, well-ventilated areas; handled exclusively with heavy-duty nitrile utility gloves, safety goggles, and a chemical-resistant apron. Never use glutaraldehyde as a spray surface disinfectant!

2. Acrylic Monomers & Methyl Methacrylate (MMA)

• Use: Custom tray fabrication, denture repairs, temporary crown fabrication.
• Hazards: High flammability, vapor inhalation hazards, potent contact skin allergen.
• Safety Protocol: Volatile vapors can rapidly penetrate standard thin latex examination gloves. Dental assistants should work under local exhaust ventilation, cure materials promptly, and use specialized nitrile or double gloves.

3. Phosphoric Acid Etchants (35%–37%)

• Use: Enamel and dentin conditioning prior to bonding adhesive placement.
• Hazards: Severe corrosive acid causing chemical burns to oral soft tissues, skin, and eyes.
• Safety Protocol: Requires precise application tips, dental dam isolation, protective patient eyewear, and immediate copious water rinsing if tissue contact occurs.

4. Nitrous Oxide ($N_2O$)

• Use: Inhalation conscious sedation.
• Hazards: Chronic trace gas exposure is linked to spontaneous abortion, congenital anomalies, liver disease, and peripheral neuropathy.
• Safety Protocol: Must utilize a scavenger system with a scavenging flow rate of 45 L/min; ensure proper nasal mask fit; conduct routine leak testing of hoses and connections with soapy water or infrared analyzers; maintain ambient exposure below the NIOSH Recommended Exposure Limit (REL) of 25 ppm time-weighted average during administration.

---

5. Emergency Eyewash Station Compliance (ANSI Z358.1 & OSHA)

OSHA mandates that emergency eyewash stations must be installed wherever employees are exposed to injurious corrosive or toxic materials:

                  EMERGENCY EYEWASH STATION REQUIREMENTS
   _____________________________________________________________________
  |  • Accessibility:   Within 10 seconds (unobstructed path of travel)  |
  |  • Operation:       Hands-free continuous flow once activated       |
  |  • Flush Duration:  Minimum 15 minutes of continuous flushing       |
  |  • Water Temp:      Tepid water between 60°F and 100°F (16°C–38°C)   |
  |  • Inspection:      Weekly activation & testing log maintenance     |
  |_____________________________________________________________________|

• Travel Distance: The eyewash unit must be located within a 10-second travel time (approximately 55 feet) across an unobstructed pathway from hazardous chemical zones (e.g., sterilization lab).
• Operation: Must activate in one single motion and provide hands-free operation so the injured worker can use both hands to hold eyelids wide open.
• Flushing Volume & Duration: Must deliver a continuous flow of tepid flushing fluid for at least 15 minutes.
• Maintenance: Must be inspected, activated, and flushed weekly to verify operation and flush out stagnant water/biofilm buildup, with records kept on an attached inspection tag.

---

6. Clinical Practice Traps for the DANB NELDA ICE

[!CAUTION] DANB Exam Trap #1: Signal Word Hierarchy on GHS Labels Exam questions often test the difference between "DANGER" and "WARNING." Remember: DANGER indicates severe hazards, while WARNING indicates less severe hazards. Words like "CAUTION" or "NOTICE" are not official GHS signal words.

[!WARNING] DANB Exam Trap #2: Secondary Container Labeling Exceptions A secondary container does not need a label only if the person who poured it uses it completely during that exact work shift. If an assistant pours surface disinfectant into an unlabeled spray bottle and leaves it in the operatory for the afternoon shift, it constitutes an immediate OSHA violation.

[!IMPORTANT] DANB Exam Trap #3: SDS Section for PPE & Exposure Limits When an exam item asks which SDS section a dental assistant must consult to find mandatory personal protective equipment and OSHA Permissible Exposure Limits (PELs), the answer is always Section 8: Exposure Controls/Personal Protection.