3.3 Hazard Communication (HazCom), GHS Pictograms, and Safety Data Sheets (SDS)

Hazard Communication (HazCom), GHS Pictograms, and Safety Data Sheets (SDS)

Modern construction relies on an enormous variety of chemical products, including solvents, sealants, curing compounds, hydraulic fluids, paints, fuels, acids, and adhesives. Without proper controls and comprehension, worker exposures cause chemical burns, organ damage, toxic asphyxiation, long-term occupational illnesses (such as silicosis and cancer), and fatal fires. To protect workers, federal regulations establish a structured framework governing chemical classification, labeling, documentation, and training.

---

Evolution of the OSHA Hazard Communication Standard (29 CFR 1926.59 / 1910.1200)

OSHA's Hazard Communication Standard (HCS), codified in construction as 29 CFR 1926.59 (referencing general industry standard 29 CFR 1910.1200), was originally enacted in 1983. Historically known as the "Right to Know" law, its initial objective was ensuring that information regarding chemical hazards was physically delivered to employers and employees.

However, early compliance revealed major shortcomings: manufacturers utilized vastly differing formats, technical jargon was confusing, and non-standardized warnings left craft workers unsure of actual risks. In 2012, OSHA harmonized the standard with the United Nations Globally Harmonized System of Classification and Labelling of Chemicals (GHS).

This historic update transformed the regulation from the "Right to Know" into the "Right to Understand." Under GHS, chemical hazards are classified through standardized universal criteria, mandatory universal pictograms, uniform signal words, and a rigid 16-section Safety Data Sheet format, guaranteeing that workers of any educational or linguistic background can rapidly comprehend chemical risks.

---

Mandatory Container Label Elements Under GHS

Under GHS requirements, every chemical container leaving a manufacturer, importer, or distributor must bear a standardized label containing six mandatory elements:

1. Product Identifier: The specific chemical name, code number, or commercial batch identifier matching the exact product identity on the corresponding Safety Data Sheet.
2. Signal Word: A standardized single word used to convey the relative severity of the hazard. There are only two legal signal words:
   • "DANGER": Reserved for severe, high-level hazards (e.g., highly flammable liquids, fatal acute poisons, severe carcinogens).
   • "WARNING": Used for less severe, moderate hazards (e.g., mild skin irritants, lower-category flammables).
   • Rule: Only one signal word may appear on a label; if a chemical has multiple hazards where one triggers "Danger" and another triggers "Warning", only "Danger" appears on the label.
3. Hazard Statements: Standardized phrases assigned to specific hazard classes and categories describing the nature and degree of the threat. Examples include: "Highly flammable liquid and vapor," "Causes serious eye damage," or "Fatal if swallowed."
4. Precautionary Statements: Standardized phrases recommending specific measures to prevent adverse exposure, organized into four operational categories:
   • Prevention: Guidelines to avoid exposure (e.g., "Keep away from heat/sparks/open flames — No smoking. Wear protective nitrile gloves.")
   • Response: Immediate first-aid and emergency measures (e.g., "IF IN EYES: Rinse cautiously with water for several minutes. Call a POISON CENTER.")
   • Storage: Safe storage parameters (e.g., "Store locked up in a well-ventilated place. Keep container tightly closed.")
   • Disposal: Environmental disposal methods (e.g., "Dispose of contents/container in accordance with local/hazardous waste regulations.")
5. Supplier Identification: The full legal name, physical address, and emergency telephone contact number of the chemical manufacturer, importer, or responsible party.
6. GHS Pictograms: Standardized visual graphic symbols enclosed in a square red border set on a point (diamond shape).

---

Workplace and Secondary Container Labeling Rules

When chemicals arrive on a job site in original manufacturer drums or buckets, those primary labels must never be defaced, covered, or removed. If a label becomes torn or illegible, it must be replaced immediately.

The Secondary Container Exemption

Craft workers frequently transfer bulk chemicals into smaller portable containers—such as transferring form release oil into a pump sprayer, or thinner into a solvent cup. OSHA mandates that all secondary containers must be labeled with the product identifier and general hazard warnings, with one specific operational exception:

The Immediate-Use Exemption: A secondary container does not require a label only if the chemical is transferred from a properly labeled container by an employee, and is intended solely for the immediate and exclusive use of that specific employee during that same work shift. If the employee leaves the container unattended, passes it to a coworker, or does not consume the entire quantity before the end of the shift, the secondary container must be formally labeled immediately.

---

The Nine GHS Hazard Pictograms and Target Risks

The GHS utilizes nine distinct pictograms. Each pictogram consists of a black symbol on a white background within a vivid red diamond border:

The OSHA Non-Mandatory Environmental Pictogram Rule

A critical question on craft certification exams concerns the Environment pictogram (dead tree and dying fish). While part of the global UN GHS framework, this pictogram is not mandatory under OSHA. OSHA's legal jurisdiction, established by the Occupational Safety and Health Act of 1970, is strictly limited to protecting human worker safety within workplace environments. Environmental protection and ecological discharges into waterways or wildlife habitats fall under the statutory jurisdiction of the Environmental Protection Agency (EPA). Consequently, an employer cannot be cited by OSHA for omitting the environmental pictogram.

---

Safety Data Sheets (SDS): The Standardized 16-Section Architecture

Under GHS, the older, non-standardized 9-section Material Safety Data Sheet (MSDS) was completely replaced by the universal 16-Section Safety Data Sheet (SDS). The 16 sections must appear in exact numerical sequence:

Sections 1 through 8: General Workplace & Emergency Handling

• Section 1: Identification: Chemical name, recommended uses, supplier identification, and 24-hour emergency phone number.
• Section 2: Hazard(s) Identification: GHS hazard classifications, signal word, hazard statements, precautionary statements, pictograms, and hazards not otherwise classified.
• Section 3: Composition/Information on Ingredients: Chemical names, CAS (Chemical Abstracts Service) registry numbers, impurities, exact concentrations or percentage ranges, and trade secret provisions.
• Section 4: First-Aid Measures: Necessary treatments by route of exposure (inhalation, skin contact, eye contact, ingestion); vital acute and delayed symptoms; indications for immediate medical attention.
• Section 5: Fire-Fighting Measures: Suitable and unsuitable extinguishing media, specific chemical fire hazards (toxic gases produced upon burning), and protective gear for firefighters.
• Section 6: Accidental Release Measures: Personal precautions, required PPE, emergency evacuation procedures, containment methods, and spill cleanup materials.
• Section 7: Handling and Storage: Safe handling guidelines, avoidance of incompatible chemical mixtures, and temperature/ventilation storage requirements.
• Section 8: Exposure Controls/Personal Protection: OSHA Permissible Exposure Limits (PELs), ACGIH Threshold Limit Values (TLVs), engineering controls (exhaust ventilation), and mandatory Personal Protective Equipment (respirator cartridge types, eye protection, glove elastomers).

Sections 9 through 11: Technical, Physical, Chemical & Toxicological Data

• Section 9: Physical and Chemical Properties: Objective chemical properties: appearance, odor, odor threshold, pH, melting/freezing points, boiling point, flash point, evaporation rate, flammability limits, vapor pressure, vapor density, relative density, water solubility, auto-ignition temperature, and viscosity.
• Section 10: Stability and Reactivity: Chemical stability, potential for hazardous polymerization, conditions to avoid (shock, heat, static), incompatible materials (acids, oxidizers), and hazardous decomposition products.
• Section 11: Toxicological Information: Detailed toxicological data: routes of exposure, related physical and toxic symptoms, acute toxicity values (LD₅₀ / LC₅₀), and formal carcinogen listings by IARC, NTP, or OSHA.

Sections 12 through 16: Non-Mandatory Regulatory Information

• Section 12: Ecological Information: Environmental toxicity, persistence, bioaccumulation potential, and soil mobility.
• Section 13: Disposal Considerations: Safe disposal practices, recycling options, and EPA hazardous waste numbers.
• Section 14: Transport Information: UN numbers, proper Department of Transportation (DOT) shipping names, hazard classes, and packing groups.
• Section 15: Regulatory Information: National and international safety, health, and environmental regulations (TSCA, SARA Title III, EPCRA).
• Section 16: Other Information: Preparation date, latest revision tracking, NFPA/HMIS ratings, and acronym keys.

---

Employer Compliance Obligations and Worker Protections

OSHA's HazCom standard imposes four strict legal mandates on every construction employer:

1. Written Hazard Communication Program: The employer must maintain a comprehensive, site-specific written HazCom program detailing how container labeling, SDS availability, and employee training are administered on the job site.
2. Hazardous Chemical Inventory: The employer must compile and maintain an active chemical inventory listing every hazardous product present on the project. This inventory serves as the master checklist to verify that an SDS is present for every chemical on site.
3. Immediate, Barrier-Free SDS Access: SDSs must be readily accessible to all craft employees during every working shift across all work areas. Employers may maintain physical binders or electronic terminals (tablets, computers). However, no barriers of any kind are permitted:
   • SDS binders cannot be locked inside a supervisor's field trailer or private vehicle.
   • Electronic systems cannot require workers to ask a supervisor for a password, navigate restricted corporate intranets, or pay subscription fees.
   • If electronic access is utilized, a reliable, hard-copy backup system or battery-backup system must exist in the event of an electrical power outage, equipment breakdown, or loss of cellular data service.
4. Employee Information and Training: Workers must receive comprehensive HazCom training prior to their initial assignment to any work area containing hazardous chemicals, and must receive additional training whenever a new chemical hazard is introduced to their job site.