## Common ground
All options are gas washing bottles, used to purify or dry gases by passing them through a liquid absorbent.
## Options at a glance
**3926.90 – Made of plastic material**
- **Defining trait:** Constructed from durable, chemically resistant plastic (e.g., polyethylene or PTFE).
- **Typical examples:** Plastic wash bottles for acid gas scrubbing in labs.
- **Best fit when:** Handling corrosive gases where glass would break or react; lightweight and impact-resistant use.
**6903 – Made of refractory ceramic**
- **Defining trait:** High-temperature resistant, non-reactive ceramic used in extreme thermal environments.
- **Typical examples:** Industrial gas scrubbers in high-heat processes (e.g., furnace exhaust).
- **Best fit when:** Exposure to very high temperatures or aggressive chemical reactions beyond plastic or glass limits.
**6909.1X – Made of ceramic**
- **Defining trait:** General ceramic construction, less heat-resistant than refractory types but still chemically inert.
- **Typical examples:** Lab wash bottles for non-corrosive gas purification.
- **Best fit when:** Moderate chemical resistance needed, lower cost than glass or plastic; not for high heat.
**7017 – Made of glass**
- **Defining trait:** Transparent, chemically inert, and ideal for visual monitoring of liquid levels and reactions.
- **Typical examples:** Standard lab gas washing bottles for air or inert gas drying.
- **Best fit when:** Need to see the process, use with non-corrosive gases, or require high purity.
## Key differences
| Feature | 3926.90 (Plastic) | 6903 (Refractory Ceramic) | 6909.1X (Ceramic) | 7017 (Glass) |
|---------------------|-------------------|----------------------------|-------------------|--------------|
| Heat resistance | Low | Very high | Moderate | Low |
| Chemical resistance | High (to acids) | Very high | High | High |
| Visibility | None | None | None | Full |
| Fragility | Low | Low | Medium | High |
## How to choose
- Is the gas highly corrosive or reactive? → 3926.90
- Is temperature very high (>500°C)? → 6903
- Do you need chemical resistance but not visibility or high heat tolerance? → 6909.1X
- Do you need to see the liquid level or reaction? → 7017
## Overlaps & pitfalls
Plastic (3926.90) and glass (7017) both resist many chemicals, but plastic lacks visibility; glass is fragile. Refractory ceramic (6903) and general ceramic (6909.1X) overlap in use, but 6903 is for extreme heat. If unsure, prioritize the **main function**: visual monitoring → glass; high heat → refractory ceramic; corrosion resistance → plastic