Rust in drinking water - is that dangerous?

Rust in the water can be recognized by the color of the tap water. Whether rust in drinking water is dangerous, where it comes from in most cases and what you can do about it, reveals this post.

Sign of rust

If the drinking water from the line has a brownish to rust-red color, it almost always means rust in the water.

The discoloration itself is mostly caused by iron and its corrosion products, in some cases manganese can contribute to the color change.

Causes of rust

A cause of rust may be that the water in the pipe has been standing for some time, for example because it was off. Due to the high line pressure, rust particles are released from the pipeline network when the water is restarted and flushed out.

Damage to the pipe network can also lead to increased rust formation. Above all, solder joints in the field of water installation are at risk here. Even older water pipes may show damage over time.

Water pipes made of iron (steel) or stainless steel are basically suitable for line installations. Galvanized steel, on the other hand, is not always a good choice. After the release of the zinc layer after a few years more iron is released into the standing water.


Running the water causes the stagnant water to drain from the pipes. In very many cases clear and clean water will follow regularly.

In the case of severely corroded or damaged lines, only troublesome troubleshooting and replacement of the damaged lines will help.

If the rust problem is due to only slight corrosion of all pipes, and if the pipes are made of galvanized iron, dosing equipment can also be used to apply a protective layer to the surface of the pipe, which restricts the rust release to the water.

Dangers due to rust

The health risk of iron and manganese in drinking water is low. The limit value of both substances in the Drinking Water Ordinance may possibly be exceeded. This can be checked with a water test.

Health damage is also to be feared by drinking the brown water in virtually no case.

Tips & Tricks

Basically, tap water should always run for a while before you drink it. All substances that reach the drinking water by standing in the pipes are thus significantly reduced.

Video Board: Dr Karl - What happens if you drink rusty water?