PBTC 50%ZEELCHEM™ 121 · Manufacturer & Supplier
PBTC 50% (2-phosphonobutane-1,2,4-tricarboxylic acid) is a chlorine- and bromine-resistant phosphonate scale inhibitor. It combines phosphonic and carboxylic groups, so ZEELCHEM™ 121 performs at high pH, high hardness and high cycles of concentration, and stabilizes zinc in alkaline corrosion programmes.
PBTC 50% Chemical Identity
| IUPAC name | 2-Phosphonobutane-1,2,4-tricarboxylic acid |
|---|---|
| Synonyms | PBTC, PBTCA |
| Molecular formula | C₇H₁₁O₉P |
| Molar mass | 270.13 g/mol |
| Chemical class | Phosphonocarboxylic acid |
| CAS number | 37971-36-1 |
PBTC 50% Specifications
Typical specification for ZEELCHEM™ 121. Every batch is dispatched with a batch Certificate of Analysis (COA).
| Parameter | Specification |
|---|---|
| Chemical name | 2-Phosphonobutane-1,2,4-tricarboxylic acid |
| Chemical formula | C₇H₁₁O₉P |
| CAS number | 37971-36-1 |
| Active PBTC | 50.0% min |
| Phosphorous acid | ≤ 0.5% max |
| Phosphoric acid | ≤ 0.2% max |
| Specific gravity | 1.27 – 1.30 g/cm³ |
| Colour (APHA) | ≤ 20 |
Applications & Recommended Dosing
Typical starting doses. Final dosing depends on your water analysis and system conditions; our chemists can help you optimize it.
| Application | Dose |
|---|---|
| High cycles of concentration cooling | 5.0 – 15.0 ppm |
| Zinc stabilization corrosion formulations | 3.0 – 8.0 ppm |
| Closed chilled water loops | 10.0 – 25.0 ppm |
| Industrial detergents & cleaners | 0.5 – 2.0% |
- High-cycle open cooling towers
- Zinc-based corrosion programmes
- Closed chilled water loops
- Industrial detergents & cleaners
- Bottle washing additives
How PBTC 50% Works
Halogen stability
Resists breakdown by chlorine and bromine, so it does not revert to orthophosphate.
High-hardness tolerance
Does not precipitate with calcium even above 1,200 ppm as CaCO₃.
Zinc stabilization
Keeps zinc in solution at pH 8.0–9.2 for continuous corrosion protection.
Key Benefits
- Excellent resistance to chlorine and oxidizing biocides
- Effective up to pH 9.5 and very high calcium hardness
- Prevents zinc hydroxide precipitation in alkaline systems
- Less orthophosphate reversion, so less calcium phosphate scale risk
- High purity: low phosphorous and phosphoric acid content
How much PBTC 50% do you need?
Packaging, Storage & Safety
⬢Packaging
- 60 kg HDPE carboys
- 250 kg virgin HDPE drums
- 1,250 kg IBC totes
- Bulk tankers
❄Storage & Shelf Life
- Store in tightly closed PE, PP or FRP containers; avoid mild steel
- Keep at 5 °C – 40 °C in a dry, ventilated area away from sunlight
- Shelf life: 24 months in sealed original packaging
⚠Handling & Safety
- Acidic (pH < 2.0) and corrosive to mild steel
- Wear goggles, nitrile gloves and a rubber apron
- Avoid breathing mist; flush any contact with plenty of water
Always read the Safety Data Sheet (MSDS/SDS) before handling. Pan-India dispatch from Vadodara, Gujarat.
TDS, MSDS & COA for PBTC 50%
Request documents instantly on WhatsApp. ZEEL PRODUCT is ISO 9001:2015, ISO 14001:2015 & ISO 22000:2018 certified.
Safety Data Sheet (MSDS)
16-section GHS-format safety, handling and transport information.
Request MSDS →PBTC 50%: Frequently Asked Questions
What is PBTC and why is it used in alkaline cooling water?
PBTC has both phosphonic and carboxylic groups. This gives it chlorine resistance and strong scale inhibition at high pH and high hardness.
What is the recommended PBTC dosage?
5–15 ppm active in high-cycle open cooling towers, and 3–8 ppm in zinc-stabilized corrosion formulations.
How does PBTC compare with HEDP and ATMP?
PBTC tolerates chlorine and high calcium better and works up to pH 9.5, where HEDP and ATMP can precipitate calcium phosphonate.
Can PBTC be used in closed chilled water systems?
Yes, at 10–25 ppm, usually blended with nitrite or molybdate corrosion inhibitors.
What is the purity of ZEELCHEM™ 121?
Active PBTC is 50% minimum, phosphorous acid 0.5% maximum, phosphoric acid 0.2% maximum and colour 20 APHA maximum.
Why is PBTC preferred in chlorinated systems?
Free chlorine above about 0.5 ppm breaks down many phosphonates into orthophosphate, which can cause calcium phosphate scale. PBTC is far more resistant.
What packaging is available for PBTC 50%?
60 kg HDPE carboys, 250 kg virgin HDPE drums, 1,250 kg IBC totes and bulk tankers.
What is the shelf life of PBTC?
24 months in sealed original packaging, stored dry and ventilated at 5–40 °C.
Is PBTC corrosive in storage?
Yes, it is acidic. Store it in PE, PP or FRP tanks and avoid mild steel.
Do you provide MSDS and COA for PBTC?
Yes. A batch COA ships with every order, and the TDS and 16-section GHS MSDS are available on request.
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Bulk pricing, samples and technical support for plants across India, from Gujarat and Maharashtra to Delhi NCR and South India.