This symbol means that blood, tissues, virus or
bacteria are present. you should wear glove to prevent
contact with them and dispose of the sample properly.

Explanation:

I downloaded the biohazard symbol from internet and attached it to this answer to show you how it is.

The presence of blood, tissues, virus or bacteria represent a risk of contamination or transmission of diseasses that must warned to avoid accidental contact that compromises the health of and individual or community.

As the question states you should wear gloves to avoid direct contact of your skin with those contaminants. Also, they should be dispossed properly, meaning that they must be handled by a specialized company.

That symbol, for example, must be exhibited at hospitals where biological wastes are temporarily stored pending collection by a company specializing in the management and disposal of biological waste.

i think tornado but not 100%