The 16 sections, as mandated by OSHA's HazCom 2012 aligned with GHS, are: (1) Identification, (2) Hazard(s) Identification, (3) Composition/Ingredients, (4) First-Aid Measures, (5) Fire-Fighting Measures, (6) Accidental Release Measures, (7) Handling and Storage, (8) Exposure Controls/PPE, (9) Physical & Chemical Properties, (10) Stability & Reactivity, (11) Toxicological Information, (12) Ecological Information, (13) Disposal Considerations, (14) Transport Information, (15) Regulatory Information, and (16) Other Information.

Emergency responders typically focus on Sections 1–6: Identification (to know the substance), Hazard Identification (to understand risks), Composition (to identify key ingredients), First-Aid Measures (for immediate care), Fire-Fighting Measures (for fire scenarios), and Accidental Release Measures (for spill containment). Section 8 (PPE) is also critical for responder safety.

MSDS (Material Safety Data Sheet) is the older, pre-GHS format with varying formats across jurisdictions. SDS (Safety Data Sheet) is the newer, globally harmonized format following the GHS standard with the fixed 16-section structure. OSHA's HazCom 2012 mandated the switch from MSDS to SDS in the United States, aligning with international standards for consistency.

Under OSHA regulations, chemical manufacturers, importers, and distributors must provide SDSs for hazardous chemicals. Employers must maintain readily accessible SDSs for all hazardous chemicals in the workplace and ensure employees are trained on how to read and use them. SDSs must be available in English, though additional language copies may be provided.

SDSs must be updated within 3 months of becoming aware of new significant information about a chemical's hazards, or when new ways to protect against hazards are identified. There is no fixed expiration date. Employers should regularly review their SDS library (at least annually) and replace outdated versions. If a chemical formulation changes, the manufacturer must issue a revised SDS.

GHS (Globally Harmonized System) pictograms are standardized diamond-shaped symbols with red borders that quickly communicate chemical hazards. The 9 pictograms are: Flame (flammables), Flame over Circle (oxidizers), Exploding Bomb (explosives), Corrosion (corrosives), Skull & Crossbones (acute toxicity), Health Hazard (carcinogens, respiratory sensitizers), Exclamation Mark (irritants), Gas Cylinder (gases under pressure), and Environment (aquatic toxicity).

Section 8 lists occupational exposure limits (OSHA PEL, ACGIH TLV, NIOSH REL), engineering controls (ventilation, enclosed systems), and personal protective equipment recommendations including respirator type, glove material, eye protection, and protective clothing. This section is critical for industrial hygienists and safety officers designing workplace safety protocols.

Generally, consumer products used in the home for their intended purpose do not require SDSs under OSHA. However, if those same products are used in a workplace setting with greater frequency, duration, or quantity than typical consumer use, employers must maintain SDSs for them. Always check workplace usage patterns against consumer norms.

Section 2 is arguably the most important for quick hazard assessment. It contains: GHS hazard classification (e.g., Flammable Liquid Category 2), signal words ("Danger" or "Warning"), hazard statements (H-codes like H225: Highly flammable liquid and vapor), precautionary statements (P-codes), and GHS pictograms. This section also describes any hazards not otherwise classified (HNOC).

If an SDS is missing: (1) Contact the chemical manufacturer or supplier immediately to request the current SDS. (2) Check online SDS databases (many manufacturers provide downloadable PDFs). (3) Document your good-faith effort to obtain the SDS. (4) Do not allow employees to use the chemical without hazard information. Under OSHA, employers can be cited if SDSs are not readily accessible during inspections.