From keeping your oat milk smooth to cutting through kitchen grease, tripotassium phosphate (TKP) leverages its strong alkalinity to solve problems across food and industrial sectors.
This guide clarifies TKP’s chemistry, regulatory status, and precise roles — while clearly distinguishing it from cleaning-only phosphates such as trisodium phosphate (TSP).
Part of Goway’s comprehensive Phosphates Encyclopedia.
1. What is TKP? (Chemistry & Key Properties)
1.1 Chemical identity
- Chemical name: Tripotassium Phosphate / Potassium Phosphate Tribasic
- Formula: K3PO4
- CAS No.: 7778-53-2
- Food additive name: Potassium phosphates, E340(iii) (EU designation under the E340 group)
TKP is a highly water-soluble, inorganic phosphate salt commonly supplied as a white, deliquescent crystalline powder.
1.2 Physicochemical properties (what makes TKP “work”)
- Solubility: Very soluble in water → fast functional performance in liquids
- Alkalinity: A 1% aqueous solution is strongly basic (around pH ~11.8) → powerful pH correction & buffering capacity in high-pH systems
- Functional mechanisms: Buffering • Chelation / sequestration (Ca/Mg) • Protein interaction control
1.3 Where TKP sits in the potassium phosphate family
Potassium phosphates are often selected by “how alkaline” they are:
- MKP (KH2PO4): acidic to mildly acidic systems
- DKP (K2HPO4): mildly alkaline buffering
- TKP (K3PO4): strong alkalinity and stronger high-pH buffering power
2. Is TKP safe? (Global regulation & boundaries)
2.1 What regulators say
European Union (E340 group): Potassium phosphates (E340) are authorised food additives in the EU framework. Specifications for listed additives are defined under Commission Regulation (EU) No 231/2012, linked to Regulation (EC) No 1333/2008.
EFSA safety re-evaluation: EFSA re-evaluated phosphates (including E338–341, E343, E450–452) and established a group ADI of 40 mg/kg body weight/day expressed as phosphorus, noting that some population groups may exceed guidance values depending on total dietary exposure.
United States (FDA): Tripotassium phosphate (potassium phosphate, tribasic) appears in FDA’s “Substances Added to Food” database (historical ingredient listing), while related potassium phosphate salts such as dipotassium phosphate are explicitly listed as GRAS in 21 CFR 182.6285. (In the U.S., “GRAS” can be established via regulation or via scientific procedures; always confirm your specific use and category.)
Codex (global reference): For international product planning, many manufacturers cross-check local law against the Codex GSFA permitted-use database.
China (GB 2760): China has issued GB 2760-2024 (effective Feb 8, 2025) as the national “Usage Standard for Food Additives,” replacing GB 2760-2014. Always validate the exact additive name/category and max use level in the latest GB text for your food category.
2.2 The non-negotiable safety boundary: grade matters
Only Food Grade (FCC / compliant food additive spec) should be used in foods and beverages. Industrial grade may contain different impurity profiles and is not intended for ingestion.
2.3 Who should be cautious?
- People with impaired kidney function: may need to manage total phosphorus intake under medical guidance (phosphate load is cumulative from diet).
- People with hyperkalemia risk: TKP is potassium-rich by design, so potassium contribution should be considered in nutrition-sensitive formulations.
- General healthy population: TKP used within lawful limits and GMP is generally considered safe by major regulatory frameworks.
3. Where is TKP used? (Dual-track applications)
3.1 Food & beverage applications (Food Grade TKP / E340(iii))
Plant-based beverages (oat/almond/soy blends)
- Prevents mineral-induced instability: TKP can bind (sequester) calcium/magnesium ions that otherwise trigger protein aggregation and flocculation in fortified beverages.
- Buffers pH in challenging systems: Its strong alkalinity helps formulators stabilize pH where high-mineral load or processing can push the system toward precipitation.
Practical formulation note: Many formulators start with a low, optimization-focused range (e.g., ~0.05–0.2% w/w) and adjust based on pH target, ionic strength, heat treatment, and local limits.
Electrolyte / functional beverages
TKP contributes potassium and phosphate ions, which may be used in electrolyte design and pH control depending on product positioning and regulatory constraints.
Processed foods (selected use cases)
Within permitted categories, potassium phosphates are used for functions such as acidity regulation, buffering, sequestration, and stabilization (category-specific permissions and limits apply).
3.2 Industrial & cleaning applications (Industrial Grade TKP — NOT for food)
- Alkaline cleaners & degreasers: Provides high-pH performance for grease removal in kitchen and equipment cleaning systems.
- Metal surface treatment: Used for cleaning/degreasing steps and certain pretreatment systems before coating processes.
- Water treatment: Can be used as part of scale-control / conditioning programs depending on system chemistry.
4. TKP vs TSP (avoid costly confusion)
These two are often confused because both are strong alkaline phosphates — but they are not interchangeable in regulated food contexts.
| Item | TKP (Tripotassium Phosphate) | TSP (Trisodium Phosphate) |
|---|---|---|
| Main ion | Potassium (K) | Sodium (Na) |
| Typical positioning | Food + industrial (grade-dependent) | Primarily industrial/cleaning |
| Nutrition angle | Can support low-sodium formulation goals | Adds sodium load |
| Core takeaway | Use Food Grade only when permitted; confirm category limits | Not a food default; do not substitute blindly |
5. How to choose the right TKP (Food Grade vs Industrial Grade)
| Dimension | Food Grade (E340(iii) / compliant spec) | Industrial Grade |
|---|---|---|
| Purity target | Typically ≥98% (per food-grade specs) | Varies (often lower / different impurity control) |
| Heavy metals & impurities | Controlled per food additive specs | Not designed for ingestion; limits differ |
| Documentation | COA + food compliance docs (as applicable) | COA + industrial quality docs |
| Packaging | Food-contact inner liner, clean handling | Industrial packaging (varies) |
| Use cases | Plant-based beverages, buffering, sequestration | Cleaning, metal treatment, water systems |
6. FAQ
Q1: Is TKP banned in food?
No. Potassium phosphates (E340 group) are authorised in the EU framework and are subject to specifications; major authorities have evaluated phosphate additives and provide intake guidance values. Always check category-specific permissions and limits in your target market. :contentReference[oaicite:8]{index=8}
Q2: Is E340(iii) safe?
When used in compliance with regulations and GMP, potassium phosphate additives are generally considered safe by regulators. EFSA established a group ADI expressed as phosphorus, highlighting that total dietary phosphate exposure matters (not just from additives). :contentReference[oaicite:9]{index=9}
Q3: Why use TKP instead of DKP in oat milk?
TKP provides stronger high-pH buffering and can be more effective when your system faces calcium-driven instability (e.g., fortified plant-based beverages). DKP may be sufficient for milder pH targets; the correct choice depends on pH, minerals, protein system, and heat process.
Q4: Can TKP be used in organic products?
Often no. Many organic standards restrict synthetic phosphates. Always confirm against your certification body’s allowed-input list (standards differ by region and certifier).
Compare Potassium Phosphates
See how TKP stacks up against DKP and MKP in alkalinity and applications:
Conclusion: Powerful — but must be used precisely
Tripotassium phosphate (TKP) is a high-performance phosphate with two distinct tracks: Food Grade for stabilizing and buffering challenging formulations (like fortified plant-based beverages), and Industrial Grade for high-alkalinity cleaning and technical processes. The value is real — but so is the need to choose the correct grade and stay within regulatory boundaries.
Note: This page is for technical information only and does not replace regulatory review or medical advice. Always verify your intended use under local regulations and product category limits.
