Reading and Understanding Safety Data Sheets (SDS)

Quick Answer

Safety Data Sheets (SDS), formerly MSDS, are documents that detail chemical hazards, safe handling procedures, and emergency response information. By law, chemical manufacturers must provide SDS for all hazardous products. The critical sections to review before using any chemical: Section 2 (Hazard Identification), Section 8 (PPE), Section 11 (Toxicology), and Section 6 (First Aid). Always keep current SDS accessible in your work vehicle and know your chemicals before using them.

Key Takeaways

• Legal requirement: OSHA requires SDS for all hazardous chemicals
• 16 standard sections: Every SDS follows identical format
• Critical sections: 2 (Hazards), 6 (First Aid), 8 (PPE), 11 (Toxicology)
• Keep accessible: Must be available to all employees during work shift
• Update regularly: Manufacturers must update SDS within 3 months of new information
• Know before using: Read SDS before using any chemical for first time

What is an SDS?

Safety Data Sheet (SDS) is a standardized document that:

• Identifies chemical hazards (health, physical, environmental)
• Provides safe handling procedures (storage, use, disposal)
• Outlines emergency response (first aid, fire, spill cleanup)
• Meets legal requirements (OSHA Hazard Communication Standard 29 CFR 1910.1200)

Formerly called: MSDS (Material Safety Data Sheet) before 2012 when GHS (Globally Harmonized System) was adopted.

Legal requirement: Chemical manufacturers must provide SDS to customers. Employers must maintain SDS for all hazardous chemicals and ensure they’re accessible to employees during work shifts.

The 16 Sections of SDS

Every SDS contains these 16 sections in this specific order:

Section 1: Identification

What it contains:

• Product name and synonyms
• Manufacturer contact information
• Emergency phone number
• Recommended use of the chemical
• Restrictions on use

What to look for:

• Emergency contact (save this in your phone)
• Intended use (confirm you’re using correctly)
• Any usage restrictions

Section 2: Hazard Identification (CRITICAL)

What it contains:

• GHS hazard pictograms (skull & crossbones, flame, corrosion, etc.)
• Signal word (Danger or Warning)
• Hazard statements (specific risks)
• Precautionary statements (how to handle safely)

What to look for:

• Signal word:
  • “Danger” = More severe hazards
  • “Warning” = Less severe hazards
• Hazard statements:
  • “Causes severe skin burns and eye damage”
  • “Toxic to aquatic life”
  • “May cause cancer”
• Pictograms: Quick visual reference for major hazards

Section 3: Composition/Information on Ingredients

What it contains:

• Chemical ingredients and concentrations
• Common name and synonyms
• CAS numbers (unique chemical identifiers)
• Impurities and stabilizing additives

What to look for:

• Active ingredients: What percentage is the actual chemical?
• Inert ingredients: Sometimes hazardous too
• Trade secret claims: Some formulations protected (but hazards still disclosed)

Section 4: First Aid Measures (CRITICAL)

What it contains:

• Symptoms of exposure (inhalation, skin, eye, ingestion)
• First aid procedures for each exposure route
• Immediate medical attention needed
• Special instructions to medical personnel

What to look for:

• Eye contact: Flush for how long? (typically 15 minutes)
• Skin contact: Remove contaminated clothing? Wash with soap and water?
• Inhalation: Move to fresh air? Artificial respiration?
• Ingestion: Rinse mouth? Induce vomiting? (usually NO)
• Note to physician: Specific treatments or antidotes?

Section 5: Fire-Fighting Measures

What it contains:

• Flammability (flash point, autoignition temperature)
• Extinguishing media (what to use/avoid)
• Specific hazards (toxic fumes, reactions)
• Protective equipment for firefighters

What to look for:

• Flash point: Below 100°F = flammable liquid
• Extinguishing media: Use water, foam, CO₂ (what’s appropriate?)
• Hazardous combustion products: What toxic fumes are generated in fire?

Section 6: Accidental Release Measures (CRITICAL)

What it contains:

• Personal precautions (PPE, evacuation)
• Environmental precautions (contain runoff)
• Methods and materials for containment and cleanup
• Emergency procedures

What to look for:

• Evacuation area: How far to clear? (typically 25-50 feet for small spills)
• Containment: Use absorbent materials? Dike?
• Cleanup: Sweep up? Neutralize first?
• Disposal: How to dispose of contaminated materials?

Section 7: Handling and Storage

What it contains:

• Safe handling practices (ventilation, grounding)
• Conditions for safe storage (temperature, separation)
• Specific end uses (compatible/incompatible materials)

What to look for:

• Ventilation: “Use in well-ventilated area” or “local exhaust required”
• Storage temperature: “Store below 80°F” or “Protect from freezing”
• Incompatible materials: “Never mix with acids” or “Separate from oxidizers”
• Special handling: “Ground containers” (static electricity prevention)

Section 8: Exposure Controls/Personal Protection (CRITICAL)

What it contains:

• Occupational exposure limits (OSHA PEL, ACGIH TLV)
• Engineering controls (ventilation, containment)
• Personal protective equipment (PPE) recommendations

What to look for:

• Exposure limits: PEL (Permissible Exposure Limit) = legal workplace limit
• Eye protection: Safety glasses? Goggles? Face shield?
• Skin protection: Gloves? What type? (nitrile, neoprene, Silver Shield)
• Respiratory protection: N95? Half-face with organic vapor cartridges?
• Body protection: Apron? Coveralls? Tyvek suit?

Section 9: Physical and Chemical Properties

What it contains:

• Appearance (color, physical state, odor)
• pH, melting point, boiling point, flash point
• Vapor pressure, density, solubility

What to look for:

• pH: Critical for storage and chemical compatibility
• Flash point: Below 100°F = flammable liquid storage requirements
• Vapor pressure: Higher = evaporates faster (more inhalation risk)
• Odor: Helps identify leaks (but don’t rely on odor for safety)

Section 10: Stability and Reactivity

What it contains:

• Chemical stability (stable, reacts with moisture/air)
• Possibility of hazardous reactions
• Conditions to avoid (heat, sparks, incompatible materials)
• Hazardous decomposition products

What to look for:

• Stability: “Stable under recommended storage conditions”
• Incompatible materials: “Strong acids, oxidizers, metals”
• Hazardous decomposition: “Decomposes to release chlorine gas”
• Polymerization: Will it react with itself? (usually no for common chemicals)

Section 11: Toxicological Information (CRITICAL)

What it contains:

• Acute toxicity (LD50 values)
• Skin corrosion/irritation data
• Serious eye damage/irritation data
• Sensitization, carcinogenicity, reproductive toxicity

What to look for:

• LD50: Lethal Dose for 50% of population (lower = more toxic)
  • Rat oral LD50 300 mg/kg = highly toxic
  • Rat oral LD50 2000 mg/kg = relatively low toxicity
• Skin corrosion: “Causes irreversible damage” vs. “Causes irritation”
• Carcinogenicity: “May cause cancer” or “No carcinogenic effect”
• Sensitization: “May cause allergic reaction”

Section 12: Ecological Information

What it contains:

• Ecotoxicity (toxicity to fish, aquatic invertebrates, plants)
• Persistence and degradability
• Bioaccumulative potential
• Mobility in soil

What to look for:

• Aquatic toxicity: LC50 (lethal concentration for 50% of fish)
  • LC50 1 mg/L = highly toxic to aquatic life
  • LC50 100 mg/L = relatively low toxicity
• Biodegradability: “Readily biodegradable” vs. “persistent”
• Bioaccumulation: “Potential to bioaccumulate” (builds up in food chain)
• Runoff precautions: “Toxic to aquatic organisms—prevent runoff to waterways”

Section 13: Disposal Considerations

What it contains:

• Waste disposal methods
• Contaminated packaging disposal
• Special precautions for incineration or landfill

What to look for:

• Disposal method: “Dispose as hazardous waste” vs. “Dispose in sanitary sewer”
• Container disposal: “Triple rinse” before recycling or disposal
• Regulatory info: RCRA (Resource Conservation and Recovery Act) hazardous waste number

Section 14: Transport Information

What it contains:

• UN number (4-digit identification number)
• Proper shipping name
• Hazard class (corrosive, flammable, etc.)
• Packing group
• Transport labels

What to look for:

• UN number: Used for emergency response (UN1791 = sodium hypochlorite solution)
• Hazard class: Class 8 (corrosive), Class 3 (flammable liquid), etc.
• Packing group: I (great danger), II (medium danger), III (minor danger)
• DOT regulations: Placarding requirements, quantity limits

Section 15: Regulatory Information

What it contains:

• Safety, health, and environmental regulations
• Chemical inventories (TSCA, DSL, EINECS)
• International regulations (EU, Canada, etc.)

What to look for:

• TSCA status: On US Toxic Substances Control Act inventory?
• SARA 313: Reportable under Section 313 (toxic release inventory)?
• CWA Clean Water Act: Toxic pollutant?
• CA Prop 65: California carcinogen/reproductive toxin warning?

Section 16: Other Information

What it contains:

• Preparation date
• Revision history
• Disclaimer
• Sources of key data

What to look for:

• Revision date: SDS updated within last 3 years? (older may be obsolete)
• Prepared by: Manufacturer or third-party service?
• Disclaimer: “Information believed accurate but not guaranteed”

How to Use SDS Effectively

Before First Use

Read these sections first:

1. Section 2: What are the hazards?
2. Section 8: What PPE do I need?
3. Section 6: What do I do if there’s a spill?
4. Section 4: What if I get exposed?

Decision questions to ask:

• Can I handle this safely? (Do I have the PPE and training?)
• Is this appropriate for the job? (Intended use match?)
• What are the emergency procedures? (First aid, spill response)

Keeping SDS Accessible

OSHA requirement:

• SDS must be readily accessible during work shift
• Can be paper copies or electronic access
• Must be available in the work area (not back at office)

Best practices:

• Print SDS: Keep in binder in work truck
• Digital backup: Store on phone or tablet (PDF format)
• Quick reference: Create one-page summary of critical info for each chemical
• Employee training: Ensure all employees know how to access and read SDS

Updating SDS

When to update:

• Within 3 months of manufacturer releasing new SDS
• Immediately if you switch to different product or brand
• Annually review all SDS for accuracy (products may be reformulated)

Where to get updated SDS:

• Manufacturer website (most current)
• Chemical distributor
• SDS management services (subscription-based)
• Upon request with chemical order

SDS Examples: Common Chemicals

Sodium Hypochlorite (12.5%)

Critical information from SDS:

• Section 2: “Causes severe skin burns and eye damage”
• Section 4: Flush eyes with water for 15 minutes
• Section 6: Neutralize with weak acid (citric, vinegar)
• Section 8: Goggles, face shield, chemical-resistant suit, gloves
• Section 11: Corrosive (Category 1), toxic to aquatic life

Key hazards:

• Corrosive to skin, eyes, respiratory tract
• Reacts with acids to release chlorine gas
• Toxic to aquatic organisms

Sodium Hydroxide (Caustic Soda)

Critical information from SDS:

• Section 2: “Causes severe skin burns and eye damage”
• Section 4: Immediate flushing critical (tissue damage continues even after exposure)
• Section 5: Not flammable but reacts exothermically with water
• Section 8: Full face shield, chemical-resistant suit, heavy-duty gloves
• Section 11: Corrosive (Category 1), severe burns

Key hazards:

• Extremely corrosive (more severe than sodium hypochlorite)
• Reacts exothermically with water (generates heat)
• Toxic to aquatic life

Oxalic Acid

Critical information from SDS:

• Section 2: “Fatal if swallowed” (kidney failure)
• Section 4: Do NOT induce vomiting, rinse mouth, drink water, seek immediate medical attention
• Section 6: Neutralize spills with baking soda or lime
• Section 8: Chemical splash goggles, respirator with P100 cartridge, chemical-resistant suit
• Section 11: Toxic if swallowed, harmful to aquatic life

Key hazards:

• HIGHLY TOXIC if ingested (kidney damage)
• Severe eye damage and skin irritation
• Very toxic to aquatic life

Common SDS Mistakes

Mistake 1: Never Reading SDS

Problem: Assuming chemical is safe based on word-of-mouth or limited experience.

Solution: Always read SDS before first use. Chemicals can behave differently than expected.

Mistake 2: Relying on Outdated SDS

Problem: Using SDS that’s 5+ years old (product may have been reformulated).

Solution: Update SDS annually or when manufacturer releases new version.

Mistake 3: Not Keeping SDS Accessible

Problem: SDS back at office while crew is on job site.

Solution: Keep printed copies in work vehicle AND digital backup on phones/tablets.

Mistake 4: Not Training Employees on SDS

Problem: Crew doesn’t know how to access or interpret SDS.

Solution: Train all employees on SDS location, format, and how to find critical information quickly.

People Also Ask

Are SDS required for all chemicals?

No—only hazardous chemicals:

Requires SDS:

• Chemicals posing health or physical hazards
• Chemicals covered by OSHA standard (29 CFR 1910.1200)
• Most pressure washing chemicals (SH, NaOH, acids, etc.)

Does NOT require SDS:

• Household products in consumer quantities (detergent, bleach)
• Food, drugs, cosmetics (regulated by FDA, not OSHA)
• Non-hazardous materials (water, sand, inert materials)

Note: Just because something doesn’t require SDS doesn’t mean it’s safe. Treat all chemicals with caution.

Can I use SDS from different manufacturers?

Generally no, but with exceptions:

Same chemical, different manufacturer:

• Basic chemical hazards identical (sodium hypochlorite is sodium hypochlorite)
• May have different concentrations or additives
• Use SDS from your specific supplier if available

Emergency situation:

• Any SDS for that chemical better than none
• Provides basic hazard information and first aid
• Follow most conservative recommendations

Best practice: Maintain SDS for every specific product you use (brand, concentration, supplier).

How long should I keep old SDS?

OSHA requirement:

• Keep current SDS only
• No requirement to keep obsolete SDS

Best practice:

• Keep current SDS in work vehicle
• Archive old SDS in office (indefinitely)
• Why old SDS? Documentation if issues arise later (exposures, lawsuits, etc.)

Electronic archiving: Scan or download old SDS and store on computer with date stamps.

Do customers need to see SDS?

Sometimes yes:

When customers might request SDS:

• Commercial properties (OSHA requires access for all employees)
• Schools and government buildings (often required)
• Healthcare facilities (infection control, chemical safety)
• Environmentally conscious customers (want to know what you’re using)

Best practice:

• Keep SDS accessible and offer to share
• Be prepared to explain hazards and safety measures
• Use SDS discussion as opportunity to demonstrate professionalism

Never: withhold SDS or claim it’s “proprietary.” SDS must be shared upon request (with limited exceptions for trade secrets).

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