## Common ground
Both options refer to calcium citrate, a compound used for calcium supplementation.
## Options at a glance
**2918.13 – Salt of citric acid**
- **Defining trait:** Chemically classified as a salt derived from citric acid and calcium.
- **Typical examples:** Pharmaceutical-grade calcium citrate tablets, dietary supplements.
- **Best fit when:** The product is purified, intended for human consumption as a nutrient supplement.
**3824.99 – Crude calcium citrate**
- **Defining trait:** Not refined; likely contains impurities or is produced in bulk without pharmaceutical standards.
- **Typical examples:** Industrial-grade material, raw intermediate in chemical production.
- **Best fit when:** The product is used in manufacturing or non-consumer applications, not for direct intake.
## Key differences
| Feature | 2918.13 (Salt of citric acid) | 3824.99 (Crude calcium citrate) |
|---------------------|-------------------------------|----------------------------------|
| Purity | High (pharmaceutical grade) | Low (raw/industrial) |
| Use | Dietary supplements | Industrial or bulk chemical use |
| Processing | Refined and purified | Unprocessed or minimally refined |
## How to choose
- Is the product intended for human dietary supplementation? → 2918.13
- Is it used in industrial processes or not yet purified? → 3824.99
## Overlaps & pitfalls
A product may be "crude" but still used in supplements if it’s processed later—this depends on final use. The key is whether the product meets purity standards for human consumption. If unclear, prioritize based on **main intended use**: supplement → 2918.13; industrial use → 3824.99