This may concern space researchers who try to prevent contamination.

He said the priority now was to prevent serious contamination to the area's water supply.

They prevent contamination to the hands and so reduce the risk of contact diseases.

Because of the sample's small size, preventing contamination is a high priority.

And the final way to prevent contamination is when the material in known to be heavily infected.

This is designed to prevent contamination getting in to the product.

This prevents contamination should the public drinking water system's pressure drop.

It focuses on food safety and methods to prevent contamination.

If that is not possible for any reason, then she must be killed to prevent further contamination.

The only way to assure that is by preventing contamination in the first place.