## Common ground
Both options are types of cable conduits—protective tubes for electrical cables—distinguished by their material composition.
## Options at a glance
**6811.89 – Asbestos cement or cellulose fiber cement**
- **Defining trait:** Made from cement-based materials with asbestos or cellulose fibers, offering fire resistance and durability.
- **Typical examples:** Older underground conduit systems, industrial building installations.
- **Best fit when:** High fire resistance and mechanical strength are needed in non-residential or industrial settings.
**6906.00 – Ceramic**
- **Defining trait:** Made from fired clay or similar ceramic materials, known for excellent heat and chemical resistance.
- **Typical examples:** High-temperature environments (e.g., near furnaces), outdoor utility installations.
- **Best fit when:** The conduit must withstand extreme heat, corrosion, or harsh outdoor conditions.
## Key differences
| Feature | 6811.89 (Asbestos/cellulose cement) | 6906.00 (Ceramic) |
|---------------------|--------------------------------------|--------------------------|
| Material | Cement with fibers | Fired clay or ceramic |
| Heat resistance | Moderate | High |
| Durability | Good | Excellent |
| Common use | Industrial, older infrastructure | Harsh environments |
## How to choose
- Is the conduit used in high-heat or corrosive environments? → 6906.00
- Is it for industrial or older building installations where fire resistance is key? → 6811.89
## Overlaps & pitfalls
Both can be used in industrial settings and offer good durability. However, asbestos cement (6811.89) is largely obsolete due to health risks—check if the product is modern or legacy. The main difference lies in heat resistance and material safety: prioritize **ceramic** for extreme conditions, **asbestos/cellulose cement** only for older systems where fire resistance was a priority. If unsure, choose based on **environmental exposure and safety standards**