---
title: "Can you mix one drain cleaner and a different drain cleaner?"
description: "One drain cleaner and a different drain cleaner: no — this one produces a toxic gas. What actually happens, and what to do instead."
url: https://atoneplace.net/can-you-mix/two-drain-cleaners/
site: "At One Place"
---

# Can you mix one drain cleaner and a different drain cleaner?

**One drain cleaner and A different drain cleaner: No — this one produces a toxic gas**

No. Drain cleaners come in strongly acidic and strongly caustic types, and combining them is violent.

> If the two have already been mixed: leave the room, open windows and doors from outside if you can reach them without breathing the air, and ring your national poison line. Do not go back in to neutralise it — adding a third chemical to a reaction in progress is the intuitive move and the wrong one, and most exposures happen to the person who returns to clear it up.

## What actually happens

Some drain products are sulfuric acid, others are sodium hydroxide, and they are sold in similar bottles for the same job. Combined in a blocked pipe they neutralise each other explosively, generating heat, spattering caustic liquid back up the drain and potentially cracking the trap. The blockage is still there afterwards.

## How people end up doing it

The first product fails to clear the drain, so someone buys a different one and pours it into a pipe still full of the first.

## What to do instead

If a drain product has not worked, the pipe is still full of it. That is a job for mechanical clearing by someone who knows what is in there, and it is worth telling them what you poured down.

## Cleaning products

| Combination | Verdict | Why |
| --- | --- | --- |
| Bleach and ammonia | Toxic gas | No. This is the classic household poisoning and it produces chloramine gas. |
| Bleach and vinegar | Toxic gas | No. Any acid plus bleach releases chlorine gas. |
| Baking soda and vinegar | Pointless | Safe, dramatic, and it leaves you with salt water. |
| Bleach and toilet cleaner | Toxic gas | No. Most toilet cleaners are acidic, so this is the bleach-and-acid reaction. |
| Bleach and rubbing alcohol | Toxic gas | No. It produces chloroform and other chlorinated compounds. |
| Hydrogen peroxide and vinegar | Do not | No — mixed in a bottle it forms peracetic acid, which is corrosive. |
| Bleach and hydrogen peroxide | Do not | No — it is exothermic and destroys both, and can spray hot liquid. |
| Vinegar and castile soap | Pointless | Safe, and it curdles into a white mess that is worse than either. |
| Vinegar and ammonia | Pointless | Not dangerous, and they cancel each other out. |

## Common questions

### Can you mix one drain cleaner and a different drain cleaner?

No — this one produces a toxic gas. No. Drain cleaners come in strongly acidic and strongly caustic types, and combining them is violent.

### What happens if you do?

Some drain products are sulfuric acid, others are sodium hydroxide, and they are sold in similar bottles for the same job. Combined in a blocked pipe they neutralise each other explosively, generating heat, spattering caustic liquid back up the drain and potentially cracking the trap. The blockage is still there afterwards.

### What should I do instead?

If a drain product has not worked, the pipe is still full of it. That is a job for mechanical clearing by someone who knows what is in there, and it is worth telling them what you poured down.

### What if I have already mixed them?

Leave the room, ventilate it from outside, and ring your national poison line. Do not go back in to neutralise it.

## Related pages

- [Bleach and ammonia](https://atoneplace.net/can-you-mix/bleach-and-ammonia/)
- [Bleach and vinegar](https://atoneplace.net/can-you-mix/bleach-and-vinegar/)
- [Baking soda and vinegar](https://atoneplace.net/can-you-mix/baking-soda-and-vinegar/)
- [Bleach and toilet cleaner](https://atoneplace.net/can-you-mix/bleach-and-toilet-cleaner/)
- [Bleach and rubbing alcohol](https://atoneplace.net/can-you-mix/bleach-and-rubbing-alcohol/)
- [Hydrogen peroxide and vinegar](https://atoneplace.net/can-you-mix/hydrogen-peroxide-and-vinegar/)
- [Bleach and ammonia](https://atoneplace.net/can-you-mix/bleach-and-ammonia/)
- [Bleach and vinegar](https://atoneplace.net/can-you-mix/bleach-and-vinegar/)
- [Bleach and toilet cleaner](https://atoneplace.net/can-you-mix/bleach-and-toilet-cleaner/)
- [Bleach and rubbing alcohol](https://atoneplace.net/can-you-mix/bleach-and-rubbing-alcohol/)
- [Hazard symbols](https://atoneplace.net/symbol/)

## Sources

- US Environmental Protection Agency — EPA (https://www.epa.gov/) [Public domain (US Government)]
- Occupational Noise Exposure — Occupational Safety and Health Administration (https://www.osha.gov/noise) [Public domain (US Government)]