Inhibited propylene glycol for hydronic heating, cooling and solar loops

RhoGard Alternative

Inhibited propylene glycol premixes and concentrate, matched to each RhoGard dilution by freeze point. Blended and shipped from Taylor, Texas, with a certificate of analysis on every lot.

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01

The short answer

Quick answer

RhoGard is Rhomar Water's aluminum-safe inhibited propylene glycol for hydronic, cooling and solar systems. As sold it is about 61-64% propylene glycol per its SDS, dyed blue, and freezes below -60 °F used straight. Rhomar rates diluted strengths by percent RhoGard in the mix, not percent glycol: 50% RhoGard freezes at about +7 °F. Our closest to straight RhoGard is Propylene Glycol 60% Inhibited at -60 °F typical. Our inhibitor chemistry is different, so match on freeze point and treat ours as an alternative, not the same fluid.

02

What to order

The products that fit this spec, and what each one is for.

For RhoGard used straight

Propylene Glycol 60% Inhibited

60% propylene glycol by weight, close to RhoGard's 61-64%. Its guaranteed maximum is -58 °F, so ask for a stronger blend if your design needs below -60 °F.

Freeze point: approx. -51 °C (-60 °F) at 60 wt% propylene glycol · Quart to 330-gallon tote · COA with every lot

See sizes and pricing TDSSDS
For 80% RhoGard (-26 °F)

Inhibited Propylene Glycol 50/50 with OAT Inhibitor

50% propylene glycol by weight premix that freezes a little colder than an 80% RhoGard mix.

Freeze point: approx. -33 °C (-28 °F) at 50 wt% propylene glycol · Quart to 330-gallon tote · COA with every lot

See sizes and pricing TDSSDS
For 60% RhoGard (0 °F)

Inhibited Propylene Glycol 40/60 with OAT Inhibitor

40% propylene glycol by weight premix, colder than a 60% RhoGard mix. Our 35/65 at 2 °F is warmer than 0 °F, so it is not the match here.

Freeze point: approx. -21 °C (-6 °F) at 40 wt% propylene glycol · Quart to 330-gallon tote · COA with every lot

See sizes and pricing TDSSDS
For 40% RhoGard (+14 °F)

Inhibited Propylene Glycol 30/70 with OAT Inhibitor

30% propylene glycol by weight premix, colder than a 40% RhoGard mix. Our 35/65 covers a 50% RhoGard mix (+7 °F).

Freeze point: approx. -13 °C (9 °F) at 30 wt% propylene glycol · Quart to 330-gallon tote · COA with every lot

See sizes and pricing TDSSDS
For RhoGard Ultra, or blended to order

100% Propylene Glycol Inhibited

96/4 inhibited propylene glycol concentrate for site blending with deionized water, or blended by us to the freeze point you need.

Quart to 330-gallon tote · COA with every lot

See sizes and pricing TDSSDS

Need a different concentration? We blend to the freeze point you specify, in pails, drums and 275- or 330-gallon totes.

03

About RhoGard

What Rhomar Water publishes about the fluids.

RhoGardVirgin propylene glycol, 61-64% per SDS, sold ready to use or for dilution; freeze protection below -60 °F and burst protection to -100 °F used straight
RhoGard UltraConcentrate, 94-97% propylene glycol per SDS; below -60 °F freeze at 70% in water
RhoGard RTUPremix custom-blended at 20-60% propylene glycol, freeze point +19 to -60 °F depending on the blend
InhibitorAlkaline filming multi-metal inhibitors, rated safe for aluminum and stainless steel; meets ASTM D1384 corrosion requirements
ColorBlue
ToxicityMarketed as non-toxic, but Rhomar states it contains non-food-grade additives
Dilution noteBelow 50% RhoGard in the system, Rhomar says to add more corrosion inhibitor

Matched by freeze point

RhoGard mix Glycol (their basis) Their freeze point Our match Our freeze point
RhoGard, used straight
61-64% propylene glycol (SDS)
Below -60 °F
Propylene Glycol 60% Inhibited
-60 °F typical, -58 °F max (60% by weight); blended stronger to order if you need colder
80% RhoGard, 20% water
Percent RhoGard in the mix
-26 °F
Inhibited Propylene Glycol 50/50 with OAT Inhibitor
-28 °F typical, -27 °F max (50% by weight)
60% RhoGard
Percent RhoGard in the mix
0 °F
Inhibited Propylene Glycol 40/60 with OAT Inhibitor
-6 °F typical, -5 °F max (40% by weight)
50% RhoGard
Percent RhoGard in the mix
+7 °F
Inhibited Propylene Glycol 35/65 with OAT Inhibitor
2 °F typical, 4 °F max (35% by weight)
40% RhoGard
Percent RhoGard in the mix
+14 °F
Inhibited Propylene Glycol 30/70 with OAT Inhibitor
9 °F typical, 10 °F max (30% by weight)
RhoGard Ultra
94-97% propylene glycol (SDS)
Below -60 °F at 70% in water
100% Propylene Glycol Inhibited
Concentrate, for site blending
RhoGard RTU
20-60% propylene glycol, custom
+19 to -60 °F by blend
The premix at or below your freeze point, or blended to order
Set to your freeze point

Source: Rhomar Water RhoGard product data sheet (freeze and burst protection chart; composition from the RhoGard, RhoGard Ultra and RhoGard RTU SDS).

04

Side by side

RhoGard compared with our inhibited propylene glycol line

Property RhoGard (published) Alliance inhibited PG Comparison
Glycol
Virgin propylene glycol
Propylene glycol
Same
Forms
RhoGard (about 62%), Ultra concentrate, RTU premixes
96/4 concentrate; 60% and 20/80 to 50/50 premixes
Same
Strength naming
Percent RhoGard in the mix
Percent propylene glycol by weight
Different
Inhibitor
Alkaline filming multi-metal package
Nitrite-containing hybrid organic-acid package
Different
Aluminum
Rated aluminum and stainless steel safe
Not rated on our propylene glycol data sheets; send your system metals with the quote request
On request
Food grade
No; contains non-food-grade additives
No. Not for food contact or potable water
Same
Color
Blue
Undyed; green or purple leak-detection dye can be added
On request
Straight-fill freeze point
Below -60 °F
-60 °F typical, -58 °F max (Propylene Glycol 60% Inhibited)
Adjusted at blend

Our column comes from our controlled technical data sheets and SDS. Their column comes from published sources; we do not test competitor fluids.

05

Questions

Which of your products replaces RhoGard used straight?

Our Propylene Glycol 60% Inhibited: about -60 °F typical against RhoGard's below -60 °F, with a guaranteed maximum of -58 °F. If your design needs a limit below -60 °F, we blend it stronger to order.

Why doesn't 50% mean the same thing on both labels?

Rhomar's chart is percent RhoGard in the mix, and RhoGard is itself only about 62% glycol, so 50% RhoGard is roughly 31% glycol. Our premixes are percent propylene glycol by weight. Pick the strength from your coldest fluid temperature, not from the number.

Is your propylene glycol aluminum-safe like RhoGard?

RhoGard is rated for aluminum and stainless steel. Our propylene glycol data sheets do not carry an aluminum rating, so send your system metals with your quote request and we will tell you which fluid fits.

Can I use it for potable water heating or food contact?

No. Ours is not food grade and is not for food contact or potable-water protection. Rhomar also states that RhoGard contains non-food-grade additives.

Can I top up a RhoGard system with your fluid?

No. Do not mix inhibitor chemistries. Drain, flush with deionized water and refill.

Can you add dye?

Yes. Our fluid ships undyed; green or purple leak-detection dye can be pre-mixed on request.

Quote a fill

Pricing, freight and lead time for your site

Tell us where the coolant goes, how much, and when it has to be there.

  • Priced for your volume, from pails to 330-gallon totes
  • Freight to your site from Taylor, Texas
  • Blended to the freeze point you specify, COA with every lot

Prefer to talk? (512) 365-6838

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RhoGard is a trademark of Rhomar Water. Alliance Chemical is not affiliated with Rhomar Water or its distributors, and our products are not RhoGard products. Comparisons use published information; confirm against the current data sheet and your system's fluid specification before switching.