"I don't want to take the slightest risk of contamination."

Though the handkerchief seemed protective, it might increase the risk of contamination, or something.

If we both go then there's a double risk of contamination or whatever.

And be sure to cover the sample immediately to reduce the risk of contamination.

This inspection has identified conditions that create a significant risk of contamination.

That makes it too big a risk of contamination.

In some cases, the water supply system's pressure is not adequate, increasing the risk of bacterial contamination.

According to the gene tech industry, the risks of such unwanted contamination are low.

Many hospitals are refusing to admit and treat them due to the risk of contamination.

The main problem was the risk of contamination from surface microbes.