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Short answer. A formaldehyde SDS (safety data sheet) lists the product as acutely toxic, corrosive, a skin sensitizer, a suspected mutagen and a carcinogen (Category 1B, H350). The two sheets compared below agree on that core, but they differ on flammability, respiratory irritation and incompatibilities, so the sheet for the exact product on your shelf is the one that governs.
This page is for laboratory staff and EHS officers who need to read a formaldehyde or formalin SDS quickly and relate it to the regulatory limits. It is general safety information, not a substitute for your institution’s chemical hygiene plan or for the sheet supplied with your product.
Definition and scope: formaldehyde, formalin and the SDS
Formaldehyde (CAS 50-00-0) is a gas at room temperature. NIOSH describes it as having a pungent, suffocating odor and as a flammable gas (lower explosive limit 7.0%, upper 73%). In laboratories it is usually handled as an aqueous solution, commonly called formalin, and labelled by suppliers as “formaldehyde solution” at a stated percentage. Both sheets examined here cover a 37%-range solution: Sigma-Aldrich F8775 (36.5-38%) and SPI-Chem Formaldehyde Solution 37% (catalog 02614-AB/DA).
Under OSHA’s formaldehyde standard, 29 CFR 1910.1048, the Hazard Communication standard (1910.1200) applies, and the classification must address cancer, skin and respiratory sensitization, irritation, acute toxicity and flammability. For the broader labelling system, see our guide to GHS classification of chemicals and the explainer on GHS labels, pictograms and hazard statements.
GHS classification compared across two real SDSs
Both sheets carry the signal word Danger. The table lists hazard statements exactly as each sheet lists them. Sigma-Aldrich’s sheet is version 6.10, revised 24 August 2015; the SPI sheet is effective 27 May 2016. Manufacturers revise sheets, so treat the table as an illustration of why sheets differ rather than as current data for either product.
| Hazard statement | Sigma-Aldrich F8775 | SPI-Chem 37% |
|---|---|---|
| H226 flammable liquid and vapour | Not listed | Listed |
| H301, H311, H331 toxic if swallowed, in contact with skin, if inhaled | Listed | Listed |
| H314 severe skin burns and eye damage | Listed | Listed |
| H317 may cause an allergic skin reaction | Listed | Listed |
| H335 may cause respiratory irritation | Listed | Not listed |
| H341 suspected of causing genetic defects | Listed | Listed |
| H350 may cause cancer | Listed | Listed |
| H370 causes damage to organs | Listed | Listed |
The SPI sheet lists methanol (CAS 67-56-1) among its components; the Sigma-Aldrich sheet lists no methanol, and carries no H226. The Sigma-Aldrich sheet also gives concentration limits, including H370 at 10% and above, and skin sensitization (H317) at 0.2% and above, which matters when you dilute a stock solution. Section 10 differs as well: the SPI sheet names strong oxidizing agents as incompatible and states that hazardous polymerization does not occur, whereas Sigma-Aldrich’s section 10.5 reads “No data available”. NIOSH, by contrast, lists strong oxidizers, alkalis, acids, phenols and urea as incompatible and notes that pure formaldehyde tends to polymerize.
Exposure limits: connecting the SDS to the regulations
An SDS rarely tells you whether your air is acceptable. These are the figures from the primary sources:
- OSHA (29 CFR 1910.1048): PEL 0.75 ppm as an 8-hour TWA, short-term exposure limit (STEL) 2 ppm over 15 minutes, action level 0.5 ppm as an 8-hour TWA.
- NIOSH Pocket Guide: carcinogen designation (Ca), recommended exposure limit 0.016 ppm TWA and a 0.1 ppm 15-minute ceiling; IDLH 20 ppm. One ppm equals 1.23 mg/m3.
- Medical surveillance: OSHA makes it mandatory for employees exposed at or above the action level or the STEL, and available on request after symptoms or an emergency.
- Warning signs: regulated areas must be marked “MAY CAUSE CANCER” and “CAUSES SKIN, EYE, AND RESPIRATORY IRRITATION”.
The legal OSHA limit and the NIOSH recommendation differ by a wide margin; the NIOSH value is a recommendation, not an enforceable limit. For monitoring and surveillance mechanics see formaldehyde PEL, STEL and action level, and for the broader picture PELs, TLVs and RELs in the laboratory.
Storage, PPE and disposal as the sheets state them
- Storage: Sigma-Aldrich specifies a cool, dry, well-ventilated place with the container tightly closed and opened containers resealed upright. SPI points to a corrosives area away from heat and ignition sources.
- Handling: the SPI sheet says to use only under a chemical fume hood.
- Eye and face: Sigma-Aldrich specifies tight-fitting goggles plus a face shield.
- Gloves: Sigma-Aldrich lists nitrile at 0.4 mm for full contact (480 minutes breakthrough) and 0.2 mm for splash contact (60 minutes), tested to EN 374 using specific KCL glove products. Those figures belong to the tested products, not to nitrile in general; see nitrile glove chemical resistance.
- Disposal: Sigma-Aldrich directs disposal through a licensed company, by chemical incineration with an afterburner and scrubber. SPI says not to let the product enter drains or sewers and notes that emptied containers retain residue. Our formaldehyde disposal guide covers the regulatory side.
Common misunderstandings
“Formalin and formaldehyde have different hazards”
Formalin is a formaldehyde solution, so the substance-level hazards are the same; what changes with the percentage are the concentration-based classifications, such as the 10% threshold for H370 on the Sigma-Aldrich sheet. Check the percentage on your label.
“All formaldehyde SDSs are interchangeable”
The comparison above shows they are not: flammability, respiratory irritation and incompatibility entries differ between two sheets for the same nominal 37% solution.
“Meeting the OSHA PEL means no cancer concern”
The SDS classifies formaldehyde as a Category 1B carcinogen, and NIOSH designates it a potential occupational carcinogen with a recommended limit far below the OSHA PEL. Compliance with the PEL is a legal minimum, not a statement of no risk.
FAQ
What does a formaldehyde SDS tell me?
It gives the GHS classification, hazard and precautionary statements, handling and storage notes, PPE, incompatibilities, first-aid measures, and disposal considerations for that specific product. It does not give your workplace air concentration.
Where do I find the SDS for formalin?
From the supplier of the product you hold, whose catalog number identifies the correct sheet. This page links the two manufacturer sheets used for the comparison above.
Is formaldehyde flammable?
NIOSH lists the gas as flammable. For solutions it depends on the product: the SPI methanol-containing sheet lists H226, the Sigma-Aldrich sheet does not.
What are the formaldehyde hazards in brief?
Acute toxicity by ingestion, skin contact and inhalation, severe skin and eye damage, skin sensitization, suspected mutagenicity, carcinogenicity (H350) and organ damage (H370), per the sheets above.
Sources
- NIOSH Pocket Guide to Chemical Hazards: Formaldehyde, read 7 November 2026.
- OSHA 29 CFR 1910.1048, Formaldehyde, read 7 November 2026.
- Sigma-Aldrich SDS, Formaldehyde solution 36.5-38% (F8775), version 6.10, revised 24 August 2015, read 7 November 2026 (copy hosted by the Weizmann Institute of Science).
- SPI Supplies SDS, SPI-Chem Formaldehyde Solution 37%, effective 27 May 2016, read 7 November 2026.
