The Hidden Dangers of Curling Incense: Exposing Chemical Toxins

For generations, many have viewed the sight of curling, intertwined incense ash as a sign of prosperity and ancestral blessing. However, behind these aesthetically pleasing curls lies a stark, alarming reality: 100% of curling incense sticks on the market are the result of industrial soaking in toxic phosphoric acid (H₃PO₄).

Every day, millions of families unknowingly inhale P₂O₅ gas—a byproduct of these chemical-laden sticks—which silently irritates the respiratory tract, causes eye irritation, and poses long-term health risks to the elderly and children. At Phu Van Huong, we believe in the philosophy of ‘natural ash fall,’ honoring the purity of traditional incense.

The Myth of ‘Prosperity Ash’: A Chemical Deception

Traditional worship is rooted in sincerity and purity. Ancient texts describe incense made from aromatic woods and herbs that, upon burning, leave behind a fine, grey ash that falls naturally—a symbol of the impermanent nature of life. In the early 2000s, industrial manufacturers exploited the desire for good fortune, creating the myth that curling ash brings wealth. In reality, no natural wood or herb can curl into a circle while burning; it defies the laws of physics. When natural wood burns at 500°C–800°C, it loses its mechanical structure and must fall. Curling is only possible through the chemical modification of bamboo fibers.

The Chemistry of Phosphoric Acid (H₃PO₄) Treatment

To achieve the ‘perfect’ curl, industrial facilities use a hazardous process:

The Process of Creating Curling Incense

Step 1: Acid Bath: Bamboo sticks are submerged in high-concentration industrial phosphoric acid for hours.

Step 2: Cellulose Esterification: The acid attacks the cellulose and lignin structure of the bamboo, creating Cellulose Phosphate, which makes the bamboo unnaturally flexible under heat.

Step 3: Coating: The treated bamboo is coated with low-grade incense powder and synthetic dyes.

At the Thuong Dat artisan workshop, Hai Phong, Vietnam, the master maker of Phu Van Huong rejects these shortcuts. We utilize hardwood alignment battens to ensure our coreless incense sticks (100% bamboo-free) burn with a clean, natural ash fall. Each stick is crafted to a precise 5.3 inches (13.5cm) length and 2.2mm–2.5mm diameter, offering a refined 45 to 60-minute burn time.