Formulation Card
FC-9.1-M
Medium bathroom cleaner
mediumSource: Chapter 9 §9.1.2
Ingredients
| Ingredient | % w/w | Function |
|---|---|---|
| SLES (28% active) | 4.0–6.0 | Primary surfactant |
| Cocamidopropyl betaine (30%) | 2.0–3.0 | Foam booster, mildness |
| Citric acid (anhydrous) | 2.0–3.0 | Primary acid, chelation |
| Sulfamic acid () | 2.0–3.0 | Secondary strong acid, scale removal |
| Hydroxyethyl cellulose (HEC) | 0.3–0.6 | Thickener, cling |
| BAC (50% solution) | 0.2 | Disinfectant (0.1% active) |
| Benzotriazole (BTA) | 0.05–0.1 | Corrosion inhibitor for chrome/brass |
| Deionized water | to 100 | Carrier |
| Fragrance | 0.2–0.4 | Sensory |
| Colorant | 0.001–0.005 | Aesthetic |
Addition Order & Process
Procedure: Disperse HEC in water at 30 °C using high-shear mixing (800–1000 rpm, 15 min). Add citric and sulfamic acids sequentially; sulfamic acid dissolves slowly and requires 10–15 min mixing. Charge surfactants (SLES, then CAPB). Add BAC separately, prediluted 1:10 in water, to avoid localized concentration pockets that could destabilize the anionic surfactant system. Dissolve BTA in warm water (40 °C) before addition. Final pH adjustment with dilute NaOH or additional acid.
Formulation Notes
Target parameters: pH 3.0–4.0; viscosity 300–800 cP (Brookfield RVT, spindle #2, 60 rpm, 25 °C) ; active disinfectant verified by two-phase titration.
Sulfamic acid (pH of 1% solution = 1.2 at 20 °C ) attacks carbonate scale faster than citric acid alone. The thickener extends contact time on vertical surfaces from seconds to minutes, a critical factor for acid effectiveness. BAC at 0.1% active achieves biomass reductions up to 64% on ceramic tile after 10 min contact . BTA forms a protective Cu(I)-BTA chemisorbed film on chrome-plated and brass fixtures, preventing dezincification and tarnishing in the acidic environment .