## Common ground
Both options cover polychlorobiphenyls (PCBs) and chloroparaffins in solid or liquid forms, grouped by physical state and wax-like properties.
## Options at a glance
**3404.90 – Solid waxes**
- **Defining trait:** The material has the character of artificial waxes, typically solid, viscous, or greasy with wax-like consistency.
- **Typical examples:** Waxy PCB mixtures used in electrical insulation or industrial lubricants.
- **Best fit when:** The product feels or behaves like a wax (e.g., pliable, non-fluid, high melting point).
**3824.99 – Non-wax solids and liquids**
- **Defining trait:** Does not have the character of artificial waxes; includes both solid forms that are brittle or crystalline and liquid forms.
- **Typical examples:** Liquid PCBs in transformers, or solid chloroparaffins used as flame retardants.
- **Best fit when:** The product is clearly non-waxy—fluid, hard, or granular—or is a liquid.
## Key differences
| Feature | 3404.90 (Waxes) | 3824.99 (Non-wax) |
|-----------------------|------------------------|----------------------------|
| Physical state | Solid | Solid or liquid |
| Wax-like character | Yes | No |
| Consistency | Greasy, pliable | Brittle, crystalline, or fluid |
## How to choose
- Does the product feel like a wax (greasy, soft, moldable)? → 3404.90
- Is it liquid or hard/crystalline (not greasy)? → 3824.99
## Overlaps & pitfalls
A solid product may be borderline if it’s waxy but also brittle—priority should go to **main physical behavior**. If uncertain, use the wax test: rub between fingers—if it feels greasy or leaves a residue, it's likely a wax. The term "artificial waxes" is key; if not applicable, avoid 3404.90