Question 1

What are Polyalkylene Glycols (PAGs)?

Accepted Answer

Polyalkylene Glycols (PAGs) are a family of synthetic base oils produced by the polymerisation of alkylene oxides (typically ethylene oxide and propylene oxide). The ratio of these monomers, along with the molecular weight, determines the PAG's final properties — including solubility, viscosity, and thermal stability.  Unlike mineral oils, which are refined from crude petroleum, PAGs are engineered at the molecular level. This means their properties can be tailored to specific applications, giving them superior performance in demanding conditions.  Why it matters: PAGs offer predictable, consistent performance that mineral oils and many other synthetics simply can't match — especially at extreme temperatures and under high loads.

Question 2

What are PAGs used for?

Accepted Answer

PAGs are used across a wide range of industries and applications:  • Industrial lubricants — gear oils, bearing lubricants, and hydraulic fluids • Metalworking fluids — as base oils for synthetic and semi-synthetic cutting and grinding fluids • Compressor lubricants — especially in refrigeration and natural gas compression • Textile lubricants — for high-speed fibre processing • Food-grade lubricants — certain PAG grades meet NSF H1 food-grade standards • Pharmaceutical and cosmetic applications — as carrier fluids and bases • Polyurethane foam production — as polymer polyols and cross-linkers

Question 3

What's the difference between water-soluble and oil-soluble PAGs?

Accepted Answer

PAGs are broadly divided into two categories based on their solubility:  Water-soluble PAGs dissolve readily in water, making them ideal for water-based metalworking fluids, fire-resistant hydraulic fluids, textile and wire-drawing lubricants, and applications where washability or cleanability matters.  Oil-soluble PAGs are designed to be compatible with mineral oils and other synthetic base oils, making them suitable for gear oils, compressor and turbine oils, automotive and heavy-duty applications, and blending with PAOs or Group III base stocks.  The solubility is controlled by the ethylene oxide / propylene oxide ratio during production. Choosing the wrong solubility type can lead to phase separation, poor lubrication, and equipment damage.

Question 4

How do PAGs compare to other synthetic base oils like PAOs?

Accepted Answer

Both PAGs and Polyalphaolefins (PAOs) are high-performance synthetic base oils, but they have distinct differences:  • Thermal stability: PAGs — Excellent | PAOs — Very good • Viscosity index (VI): PAGs — 200–300+ | PAOs — 130–150 • Water solubility: PAGs — Available (water-soluble grades) | PAOs — Not soluble • Lubricity / film strength: PAGs — Excellent | PAOs — Good • Deposit control: PAGs — Excellent | PAOs — Good • Biodegradability: PAGs — Generally good | PAOs — Moderate  Key takeaway: PAGs excel in applications requiring high viscosity index, water solubility, low deposit formation, and excellent lubricity. PAOs are preferred where oxidation stability and broad compatibility are paramount.

Question 5

What temperature range can PAGs operate in?

Accepted Answer

PAGs are known for their exceptional thermal performance:  • Low temperature: Many PAG grades remain fluid well below −30°C, with some grades functional down to −40°C or lower. Their high viscosity index means viscosity doesn't increase dramatically at low temperatures. • High temperature: PAGs can operate continuously at temperatures up to 200°C and higher in some formulations. • Thermal stability: At elevated temperatures, PAGs tend to decompose cleanly — without forming the carbonaceous deposits (varnish, sludge) that mineral oils produce.  This means longer oil life and fewer oil changes in high-temperature applications.

Question 6

Are PAGs biodegradable and environmentally friendly?

Accepted Answer

Biodegradability varies by PAG type:  • Water-soluble PAGs are generally considered readily biodegradable (especially lower molecular weight grades), making them a preferred choice in environmentally sensitive applications. • Oil-soluble PAGs have moderate biodegradability — better than mineral oils but not as readily biodegradable as some esters or natural oils. • OECD 301B tests show many PAG grades achieving >60% biodegradation within 28 days.  Additionally, PAGs are non-toxic in their base form (many grades meet food-grade standards), low in volatility, and capable of reducing overall oil consumption due to longer service life.  Important note: Biodegradability should be confirmed for the specific grade and molecular weight.

Question 7

What viscosity grades are available for PAG base oils?

Accepted Answer

PAGs are available in an extremely wide viscosity range — one of their key advantages:  • ISO VG 7 to ISO VG 460+ for conventional industrial grades • Even higher viscosity grades available for specialised applications (up to several thousand cSt at 40°C) • The high viscosity index (VI) of PAGs means the viscosity remains more stable across temperature changes  Selecting the right viscosity depends on operating temperature range, equipment speed and load, required film thickness, pumpability requirements, and compatibility with existing system components.

Question 8

Are PAGs compatible with mineral oils and other base stocks?

Accepted Answer

Compatibility depends on the PAG type:  • Water-soluble PAGs are NOT compatible with mineral oils — mixing causes separation and performance issues • Oil-soluble PAGs ARE designed to be compatible with mineral oils, PAOs, and Group I–III base stocks • Partially soluble PAGs have limited compatibility and should be tested before use  Other compatibility considerations: • Seals and elastomers: PAGs are generally compatible with most common seal materials (Viton, NBR, silicone), but always verify seal compatibility. • Additives: Some additive packages designed for mineral oils may not be fully soluble in PAGs. • Paints and coatings: Some PAGs can soften or dissolve certain paints — check compatibility with coated components.  Rule of thumb: Always run a compatibility test before switching base oils.

Question 9

What certifications and regulatory compliance do PAG base oils have?

Accepted Answer

PAG base oils from reputable manufacturers typically carry:  • EU REACH — Mandatory for substances placed on the EU market • UK REACH — Mandatory for substances placed on the Great Britain market • NSF H1 — Food-grade lubricant registration for incidental food contact • Kosher certification — For applications requiring kosher-compliant materials • Halal certification — For applications requiring halal-compliant materials • ISO 9001 — Manufacturer quality management system certification  If you're supplying into regulated industries (food, pharmaceutical, cosmetics), the right certifications aren't optional — they're a requirement. Meecarigno can supply PAGs with documented compliance for each of these standards.

Question 10

What is the shelf life of PAG base oils?

Accepted Answer

PAG base oils typically have a shelf life of 12–24 months when stored correctly (sealed, dry, cool conditions, away from direct sunlight). Some grades have indefinite shelf life in sealed containers — PAGs are chemically stable and don't degrade the way mineral oils can.  Best storage practices: • Store in original sealed containers • Keep at temperatures between 10°C and 40°C • Avoid moisture ingress (especially for water-soluble PAGs, which are hygroscopic) • Rotate stock using FIFO (first-in, first-out) • Keep containers sealed when not in use to prevent contamination

Question 11

How are PAG base oils supplied and shipped?

Accepted Answer

PAGs are available in multiple packaging formats:  • Drums — typically 200 Kg steel or plastic drums • IBC totes — 1,000 Kg intermediate bulk containers • Bulk supply — road tankers or ISO containers for large-volume customers • Sample quantities — 1 Kg to 5 Kg samples for evaluation and testing  PAGs are classified as non-hazardous for transport in most grades. Documentation includes Certificate of Analysis (CoA), Safety Data Sheet (SDS), and packing list. At Meecarigno, we manage the full supply chain — from manufacturer to your facility — with tracked shipments, documented quality, and flexible order sizes.

Question 12

Why should I source PAGs through Meecarigno rather than directly from a manufacturer?

Accepted Answer

While buying directly from a manufacturer sounds straightforward, there are real advantages to working with a specialised distributor like Meecarigno:  • Flexible volumes — We can supply anything from single IBC or pallet to a full ISO container • Multiple manufacturers, one point of contact — Access to multiple grades and price points without managing multiple supplier relationships • EU/UK compliance handled — We manage REACH registration, import documentation, and customs clearance • Quality assurance — Every shipment comes with CoA and SDS documentation under our ISO 9001 QMS • Technical support — Grade selection, formulation troubleshooting, and documentation for your downstream customers • Competitive pricing — Our relationships with multiple manufacturers mean better pricing • Risk-managed supply chain — Backup suppliers, contingency logistics, and a documented risk register

Grade	Solubility	v@40°C (cSt)	v@100°C (cSt)	VI	Pour Point	Flash Point
PAG 22	Water-soluble	22	4.5	220	-40°C	200°C
PAG 32	Water-soluble	32	6.5	230	-37°C	210°C
PAG 46	Water-soluble	46	8.5	240	-35°C	220°C
PAG 68	Water-soluble	68	11.5	245	-33°C	225°C
PAG 100	Water-soluble	100	16.0	250	-30°C	230°C
PAG 150	Water-soluble	150	22.0	255	-28°C	235°C
PAG 22	Oil-soluble	22	4.5	220	-42°C	195°C
PAG 32	Oil-soluble	32	6.5	230	-39°C	205°C
PAG 46	Oil-soluble	46	8.5	240	-36°C	215°C
PAG 68	Oil-soluble	68	11.5	245	-34°C	220°C
PAG 100	Oil-soluble	100	16.0	250	-31°C	225°C
PAG 150	Oil-soluble	150	22.0	255	-28°C	230°C
PAG 220	Oil-soluble	220	30.0	260	-25°C	235°C
PAG 320	Oil-soluble	320	40.0	265	-22°C	240°C
PAG 460	Oil-soluble	460	52.0	270	-20°C	245°C

Material / Base Oil	Water-Soluble PAG	Oil-Soluble PAG
Mineral Oil (Group I–III)	Incompatible	Compatible
PAO (Polyalphaolefin)	Incompatible	Compatible
Other PAGs (same solubility)	Compatible	Compatible
Other PAGs (opposite solubility)	Incompatible	Incompatible
Water	Soluble	Insoluble
Nitrile Rubber (NBR)	Compatible	Compatible
Viton (FKM)	Compatible	Compatible
Silicone Rubber	Compatible	Compatible
EPDM	Compatible	Compatible
PTFE (Teflon)	Compatible	Compatible
Paints & Coatings	Test first	Test first
Additives (mineral-oil packages)	Limited solubility	Good solubility

Polyalkylene Glycol (PAG) Technical Reference Guide

Get the Free PAG Technical Guide

Frequently Asked Questions

PAG Viscosity Reference Chart

PAG Compatibility Chart

Get the Free PAG Technical Guide

Talk to Our Technical Team