Sulfuric Acid SDS: How to Read It, Hazards and Exposure Limits

Short answer: A sulfuric acid SDS (CAS 7664-93-9) classes the chemical as fatal if inhaled, severely skin- and eye-damaging and possibly corrosive to metals, with the signal word “Danger”. It does not burn, but it reacts violently with water and many other materials. Exposure limits differ by body: 1 mg/m³ (NIOSH, OSHA) versus 0.2 mg/m³ (ACGIH, thoracic fraction).

What a sulfuric acid SDS contains

Safety data sheets follow the 16-section GHS layout; see GHS labels, pictograms, signal words and hazard statements and, for older sheets, SDS vs MSDS. For sulfuric acid, these are the sections worth reading closely, with values from the two public references cited below.

SDS section	What to look for	Reference value
1 and 14: identity and transport	CAS number, UN number	CAS 7664-93-9; UN1830 and UN1832 (CCOHS); also called battery acid
2: hazard identification	Classes, signal word, hazard statements	Acute toxicity (inhalation) Category 2; skin corrosion Category 1; serious eye damage Category 1; “Danger”; may be corrosive to metals (CCOHS, citing CNESST)
7: handling and storage	Conditions and incompatibles	Cool, dry, away from sunlight, heat and incompatibles; avoid bulk indoor storage; never reuse empty containers (CCOHS)
8: exposure controls and PPE	Limit values, gloves, eye and respiratory protection	See the comparison below
10: stability and reactivity	Incompatible materials	Organic materials, chlorates, carbides, fulminates, water, powdered metals (NIOSH)

GHS hazards and signal word

CCOHS lists the hazard statements “Fatal if inhaled” and “Causes severe skin burns and eye damage”, with the signal word “Danger”. Sulfuric acid will not burn, so the answer to “is sulfuric acid flammable?” is no; however, it reacts with metals to give flammable hydrogen, and combustion of surrounding materials can produce sulfur oxides (CCOHS). For corrosive-chemical handling in general, see corrosive chemicals in the lab.

Exposure limits compared

This is the comparison a single-product SDS does not give you. All values are time-weighted averages in mg/m³ unless stated.

Body	Value	Source
NIOSH REL	1 mg/m³ TWA	NIOSH Pocket Guide, entry 0577
OSHA PEL	1 mg/m³ TWA	NIOSH Pocket Guide, entry 0577
ACGIH TLV	0.2 mg/m³ TWA (thoracic fraction), A2 for strong inorganic acid mists containing sulfuric acid	CCOHS
NIOSH IDLH	15 mg/m³	NIOSH Pocket Guide, entry 0577

The TLV is five times lower than the REL and PEL, and CCOHS notes that limits vary by Canadian jurisdiction. Section 8 of your SDS shows which value the supplier chose, so check it against the one your institution or regulator applies. Background on the differences is in PELs, TLVs and RELs in the laboratory.

Incompatibilities and storage

NIOSH lists organic materials, chlorates, carbides, fulminates, water and powdered metals as incompatible; the acid reacts violently with water, releasing heat, and is corrosive to metals. CCOHS adds that aluminum alloys and carbon steel are corroded, and recommends inspecting containers for leaks, damage and crystallization. For segregation planning see chemical storage compatibility and segregation rules.

PPE and first aid

For 30-70% acid, CCOHS names butyl rubber, neoprene, PVC and Viton gloves, goggles plus a face shield, and a separate corrosion-resistant local exhaust. NIOSH advises preventing skin and eye contact, removing wet or contaminated clothing, and providing an eyewash and quick drench where solutions above 1% are used. Its respirator table runs from supplied-air and powered air-purifying options up to 15 mg/m³ to pressure-demand SCBA for emergency or IDLH conditions. Nitrile is not on the CCOHS list for this acid; see nitrile glove chemical resistance before assuming it applies. For first aid, CCOHS says to flush skin or eyes for at least 30 minutes and, after inhalation, move to fresh air and seek urgent care because pulmonary edema can be delayed. This is general reference information, not medical advice.

Concentration and which SDS to use

Suppliers publish a separate SDS per concentration (for example 1 M, 10%, 4%, 50%, 93-99%), and the GHS class of a mixture depends on how much acid it contains. Check Section 2 of the sheet for the exact bottle you hold, not a neighbouring concentration. Checklist for a purchased SDS:

• The concentration on the label falls inside the range the SDS covers.
• The revision date is recent and the supplier name matches the label.
• Section 8 states which exposure limit it uses.
• Sections 7 and 10 match your storage arrangement.

The manufacturer SDS portals (Sigma-Aldrich, Fisher Scientific, Flinn Scientific, Columbus Chemical) each let you search by product and download the PDF.

Common misunderstandings

• “It does not burn, so it is low risk.” It does not burn, but it is classified fatal if inhaled and causes severe burns.
• “Water is the safe thing to add.” CCOHS says never add water to a corrosive and always add corrosives slowly to cold water.
• “There is one exposure limit.” The values above differ by a factor of five.
• “Acid sheets are interchangeable.” See the concentration section.

Hydrofluoric acid has a very different hazard profile; see hydrofluoric acid safety. For a solvent comparison of how an SDS reads, see the acetone SDS guide.

FAQ

What are the hazards of sulfuric acid?

Fatal if inhaled, severe skin burns and serious eye damage, and possible corrosion of metals, with the signal word Danger (CCOHS). It also reacts violently with water.

Is sulfuric acid flammable?

No, it will not burn (CCOHS), but its reaction with metals produces flammable hydrogen.

Where can I get a sulfuric acid SDS PDF?

From the supplier of your product: Sigma-Aldrich, Fisher Scientific, Flinn Scientific and Columbus Chemical each host sheets by product and concentration.

Sources

• NIOSH Pocket Guide to Chemical Hazards: Sulfuric acid, read 2026-11-07.
• CCOHS OSH Answers: Sulfuric Acid, revised 2023-01-27, read 2026-11-07.