Technical Data Sheet

Propylene Glycol 50% – USP Grade (C3H8O2)

USP Grade · 50%

Alliance Code: 50-propylene-glycol-usp-grade
Reviewed: 2026-07-06
Revision: 1.4

CAS number: 57-55-6
Structure: Structure · PubChem
Grade: USP Grade · 50%

Last reviewed 2026-07-06 by Andre Taki, Chief Commercial Officer.

Identity & Composition

Product Name: Propylene Glycol 50% – USP Grade (C3H8O2)
Alliance Code: 50-propylene-glycol-usp-grade
Grade: USP Grade
Concentration: 50%
CAS Number: 57-55-6PubChem
Formula: —PubChem
Molecular Weight: 76.09PubChem
Product Type: Mixture

Specifications

Test	Specification	Typical	Method	Source
Assay	50.0 - 51.0 %, by volume	50.09 %	—	Interpreted
Freeze point	-28.6 °F (-33.7 °C) max	-28.8 °F (-33.8 °C)	ASTM D1177	Interpreted
Dilution water	Purified Water USP; conductivity ≤ 1.3 µS/cm @ 25 °C	Passes test	USP <1231> / conductivity USP <645>	Interpreted
Acidity	not more than 0.10 mL of 0.10 N sodium hydroxide	0.03	USP monograph titration, 0.10 N NaOH	Interpreted
Chloride	0.0035% max	0.000018 %	USP <221>	Interpreted
Heavy metals	2.5 ppm max	0.25 ppm	Heavy metals (as Pb), sulfide colour comparison against lead standard	Interpreted
Iron	0.26 ppm max	0.019 ppm	—	Interpreted
Limit of Diethylene Glycol	0.05% max	0.0019 %	GC, flame ionization detector, 0.53-mm x 30-m fused-silica G43 column, 2,2,2-trichloroethanol internal standard	Interpreted
Limit of Ethylene Glycol	0.05% max	0.00028 %	GC, flame ionization detector, 0.53-mm x 30-m fused-silica G43 column, 2,2,2-trichloroethanol internal standard	Interpreted
Residue on ignition	0.0036 wt% max	0.00029 wt%	Ignition of 50 g, residue moistened with 0.5 mL sulfuric acid and ignited to constant weight	Interpreted
Sulfate	0.0031% max	0.00031 %	USP <221>	Interpreted
arsenic	0.5 ppm max	0.007 ppm	—	Interpreted
dpg	0.05 % max	0.018 %	—	Interpreted
pb	0.51 mg/kg max	0.0037 mg/kg	—	Interpreted
meg	0.0005 % max	0.00028 %	—	Interpreted
po	0.0005 % max	0.00010 %	—	Interpreted
tpg	0.015 % max	0.0021 %	—	Interpreted
Odor	Pass	Passes test	Sensory (odor) evaluation	Interpreted
Residual solvents	Pass	Passes test	USP <467>	Interpreted
Suspended matter	Pass	Passes test	—	Interpreted
Composition	50 % propylene glycol / 50 % deionized water, by volume	Conforms	By formulation; confirmed by specific gravity	Interpreted

Values are reproduced from the current product reference. Source labels do not by themselves establish a supplier guarantee or a test result for your lot. Confirm applicable acceptance limits and request lot-specific documentation.

Available GradesSame CAS, alternate grades and concentrations

Grade	Concentration	Typical Assay	SKU	TDS
This grade USP Grade	50%	—	current	current
—	60%	—	propylene-glycol-60-inhibited	View TDS →
Technical	60%	—	propylene-glycol-60-technical-grade	View TDS →
USP	60%	—	propylene-glycol-60-usp-grade	View TDS →
Technical Grade	40%	—	40-propylene-glycol-technical-grade	View TDS →
USP Grade	40%	—	40-propylene-glycol-usp-grade	View TDS →
—	20%	—	propylene-glycol-20-inhibited	View TDS →
Technical	20%	—	propylene-glycol-20-technical-grade	View TDS →
USP	20%	—	propylene-glycol-20-usp-grade	View TDS →
Technical Grade	—	—	propylene-glycol-technical-grade	View TDS →
USP Grade	—	—	propylene-glycol-usp-grade	View TDS →

Typical assay shown is the rolling-window mean from the sibling product's most recent lots. Grade selection drives downstream end-use — verify the sibling grade matches your specification before substitution.

Physical & Chemical Properties

Property	Value	Source
Appearance	Clear, colorless to pale liquid	Adjudicated
Color	10 APHA (maximum)	Interpreted
Odor	Mild, characteristic	Adjudicated
pH	Essentially neutral (unbuffered blend)	Adjudicated
Specific Gravity	1.046 (20 °C)	Adjudicated
Density	1.046 g/mL at 20 °C	Adjudicated
Boiling Point	~106 °C	Adjudicated
Melting Point	-34 °C (freeze / crystallization onset)	Adjudicated
Flash Point	Not flammable (aqueous solution)	Adjudicated
Solubility (water)	Miscible with water	Adjudicated

Regulatory & Transport

DOT / 49 CFR

UN Number: Not regulatedAdjudicated
Hazard Class: Not regulatedAdjudicated
Packing Group: Not regulatedAdjudicated
Proper Shipping Name: Not regulatedAdjudicated

GHS / OSHA HCS 2024

Signal Word: Not regulatedAdjudicated
H-Codes (Hazard Statements): Not applicableECHA C&L Inventory
P-Codes (Precautionary Statements): Not applicableECHA C&L Inventory

Occupational Exposure Limits

OSHA PEL (29 CFR 1910.1000): —no canonical
ACGIH TLV: —no canonical
NIOSH REL: —no canonical
NIOSH IDLH: —no canonical

Transport descriptions reflect 49 CFR 172.101 lookup at time of publication. Sourced data: NIOSH Pocket Guide for REL/IDLH, OSHA Z-Tables for PEL. Always verify against the latest regulatory text before shipment-critical decisions.

Supplier Qualification Packet

One zipped download containing the TDS, SDS, latest lot COA (when available), and a fresh Letter of Continuing Guaranty for Propylene Glycol 50% – USP Grade (C3H8O2). Every file included is SHA-256 hashed and listed in a manifest your QA team can audit.

Download audit packet

Applications

Ready-to-use propylene glycol and water blend (50% PG): heat-transfer fluid and antifreeze for closed-loop systems; humectant and solvent carrier.Adjudicated

Storage & Handling

Recommended Storage: Keep tightly closed (hygroscopic) in a cool, dry place away from oxidizers. Stainless steel, carbon steel, polyethylene or polypropylene containers.Adjudicated
Handling Precautions: Chemical-resistant gloves and splash goggles. Avoid contact with hot surfaces and hot process equipment. Inhibitor packages deplete in service — monitor rather than top up blindly.Class-level guidance — not product-specific; the SDS controls.
Incompatibilities: Strong oxidizing agents; strong acids; strong bases.Adjudicated
Shelf Life: Consult Technical Services for product-specific shelf life

For full hazard, PPE, and emergency response guidance, refer to the Safety Data Sheet (SDS) for this product. The SDS controls in all cases where guidance differs.

Packaging & Logistics

Shipping Description (US DOT)

Not regulated for transport.

Confirm against shipping documents and carrier requirements before tender.

NMFC Class

Revision History

Last reviewed 2026-07-06 by Andre Taki, Chief Commercial Officer, DOT Hazmat–certified (49 CFR 172.704).

Version	Date	Change	Trigger
1.4	2026-10-13	Canonical data updated: 5 fields changed via the provenance/adjudication pipeline. incompatible_materials· canonical change (coa.data_provenance / adjudication) conditions_to_avoid· canonical change (coa.data_provenance / adjudication) hazardous_decomposition_products· canonical change (coa.data_provenance / adjudication) storage_precautions· canonical change (coa.data_provenance / adjudication) recommended_use· canonical change (coa.data_provenance / adjudication)	canonical_change
1.3	2026-09-09	Canonical data updated: 1 field changed via the provenance/adjudication pipeline. physicalProperties· canonical change (coa.data_provenance / adjudication)	canonical_change
1.2	2026-07-24	Canonical data updated: 1 field changed via the provenance/adjudication pipeline. physicalProperties· canonical change (coa.data_provenance / adjudication)	canonical_change
1.1	2026-07-06	Canonical data re-verified: 4 fields updated against independent vendor SDSs, CLP Annex VI, 49 CFR, and OSHA HazCom 2024 (GHS classification, hazard/precautionary codes, signal word, physical properties as applicable). countryOfOrigin· canonical adjudication / reground (coa.data_provenance) dotSubsidiaryHazardClass· canonical adjudication / reground (coa.data_provenance) hsCode· canonical adjudication / reground (coa.data_provenance) physicalProperties· canonical adjudication / reground (coa.data_provenance)	canonical_change
1.0	2026-05-20	Initial URL-first TDS published from canonical chemistry registry.	initial

This Technical Data Sheet is provided for technical reference. The Safety Data Sheet (SDS) controls in all cases where guidance differs. Values reflect Alliance Chemical canonical data at time of generation; subsequent revisions are recorded in the Revision History above.