Based on the provided data, here is the detailed analysis for Calcined Kieselguhr Powder formatted as a Wiki-style professional guide.

🧪 Calcined Kieselguhr Powder (Diatomaceous Earth): HS Code & Customs Guide 2026

🌐 HS Code Classification & Taxation Analysis | 2026 Customs Decoded | Professional Clearance Strategy

📌 一、Product Definition & Classification: What is "Calcined Kieselguhr"?

Calcined Kieselguhr (also known as Diatomaceous Earth or Diatomite) is a naturally occurring, soft, siliceous sedimentary rock formed from the fossilized remains of diatoms (microscopic algae).
In the context of International Trade, it falls into two distinct categories based on its processing state and intended use:

1. Raw/Calcined Siliceous Earths (Chapter 25):

   • Description: Natural earths that are either unprocessed or merely calcined (heated to remove moisture/organics) but not activated.
   • Key Characteristic: Retains natural physical properties; used as absorbents, filters, or fillers.
   • Critical Factor: Apparent Specific Gravity (Density). If the specific gravity is ≤ 1.0, it falls under a specific subheading with higher duties.

2. Activated Natural Mineral Products (Chapter 38):

   • Description: Kieselguhr that has undergone activation (chemical/thermal treatment to increase porosity and adsorption capacity).
   • Usage: Specifically as a carrier, filtering medium, or catalyst support in industrial processes.
   • Note: The input data explicitly flags a retrieval error for "Activated" status under HS Code 3802.90, indicating potential classification ambiguity or data gaps.

⚠️ Critical Distinction:
- If the product is just calcined (dried/sterilized) but not activated → It belongs to Chapter 25 (2512.00).
- If the product is activated (treated for adsorption) → It belongs to Chapter 38 (3802.90).

📦 二、HS Code Classification Details (2026 Tariff Reference)

🔍 Analysis of the "Calcined" Ambiguity:
- Scenario A: If you import Calcined Kieselguhr that is NOT activated (standard filter aid or filler) and has a specific gravity ≤ 1.0, it MUST be declared under 2512.00.00.00.
- Scenario B: If the powder is Activated (treated for adsorption) and used as a carrier, it may fall under 3802.90.20.00 or 3802.90. Note: The provided data shows a "Failed to retrieve tax information" error for the generic 3802.90 code, requiring manual verification.

💰 三、2026 Tariff Rate Breakdown (Detailed Tax Clauses)

✅ Applicable Country: China (Export/Import context implied by "Basic/Additional" terminology)
✅ Product: Calcined Kieselguhr (Diatomaceous Earth)
✅ Key Condition: Apparent Specific Gravity ≤ 1.0

🎯 1. HS Code 2512.00.00.00 (Specific Gravity ≤ 1.0)

This is the most likely classification for light, calcined diatomaceous earth used as a filler or filter aid.

📌 Tax Clause Explanation:
- Basic Duty (0.0%): As a natural mineral product (Chapter 25), the standard MFN rate is often zero to encourage raw material import for processing.
- Additional Duty (25.0%): This represents a significant "Additional Tariff" (加征关税). This is likely a result of trade measures (e.g., Section 301 retaliatory tariffs or specific bilateral trade friction) targeting specific mineral products from the origin country.
- Calculation: Duty = CIF Value × 25%.
- Risk: Even though the "Basic" tax is free, the 25% additional tax drastically increases the landed cost. DO NOT assume it is duty-free!

🎯 2. HS Code 3802.90.20.00 (Activated Clays & Earths)

If the kieselguhr is chemically "activated" for filtration/adsorption.

📌 Strategic Advantage:
- If the product can be technically classified as "Activated" (3802.90.20.00), it enjoys a 0% Total Tax Rate (Both Basic and Additional are 0.0%).
- Strategy: If your product allows for slight processing to be defined as "Activated," this pathway saves 25% immediately.

🎯 3. HS Code 3802.90.50.00 (Other Activated Products)

🛠️ 四、Customs Clearance Practical Advice (Actionable Tips)

✅ 1. Product Classification Strategy (The "25% Trap")

⚠️ CRITICAL WARNING: Do NOT blindly declare "Calcined Kieselguhr" as 2512.00.00.00.
- If the specific gravity is ≤ 1.0, you will face a 25% Additional Tax.
- Solution: Check if the product has been Activated (treated with acid/heat to increase surface area).
- If Activated: Declare under 3802.90.20.00 (0% tax).
- If Not Activated: You must accept the 25% tax or re-evaluate the product specs (e.g., is the specific gravity > 1.0?).

✅ 2. Documentation Checklist

To avoid the "Failed to retrieve tax information" error on 3802.90 and ensure correct classification:

✅ 3. Shipment & Labeling

• Labeling: Ensure the label distinguishes between "Calcined" (25% tax risk) and "Activated" (0% tax benefit).
• Packaging: If shipping to a country with specific gravity thresholds, ensure the packaging indicates the density clearly.

🌍 五、Risk Assessment & Cost Saving Summary

🎯 Final Conclusion:
For Calcined Kieselguhr Powder, the difference between a 25% tax and 0% tax lies entirely in the technical definition (Activated vs. Calcined) and Specific Gravity.
Action: Verify if the product can be classified as "Activated Earth" (3802.90.20.00). If so, 0% tax is achievable. If it remains a simple calcined earth with specific gravity ≤ 1.0, 25% additional tax is unavoidable.

📌 Pro Tip:

"Don't just say 'Calcined'; Say 'Activated' if possible!"
A small change in the product description and technical spec sheet can save you 25% on every shipment. Always consult a customs broker to validate the "Activation" status before shipping.

✨ Smart Trade, Zero Surprises!
💼 Your profit margin depends on the right HS Code.