Microbes that are fatal and have no treatment or vaccines should be handled in a lab of what biosafety level?

A. Louis Pasteur: Louis Pasteur made significant contributions to microbiology and germ theory, including the development of pasteurization and vaccines, but he did not specifically establish hygiene standards in healthcare settings.

B. Robert Koch: Robert Koch is known for identifying the causative agents of diseases such as tuberculosis and anthrax and developing Koch’s postulates, but he focused on microbiology research rather than hygiene practices in hospitals.

C. Rudolf Virchow: Rudolf Virchow contributed to cellular pathology and emphasized the importance of social and environmental factors in disease, but he did not establish hygiene standards in clinical care.

D. Florence Nightingale: Florence Nightingale is credited with establishing hygiene standards in healthcare settings through her work during the Crimean War, emphasizing sanitation, clean water, and proper ventilation to reduce infection rates and improve patient outcomes.

A. Irritant to skin, eyes, or respiratory tract: The Globally Harmonized System (GHS) pictogram for an irritant is a diamond containing an exclamation mark (!). This symbol is used for less severe health hazards like skin or eye irritation.

B. Health hazard: While acute toxicity is a health hazard, the specific pictogram for a range of serious, but non-acute, long-term health issues (like carcinogenicity, mutagenicity, or respiratory sensitization) is a diamond containing a human silhouette with a starburst over the chest (often called the "man exploding" symbol).

C.Acute toxicity; fatal: The skull and crossbones symbol is an internationally recognized icon representing poison or danger of death. In the GHS, this specific pictogram is used for substances that are toxic or fatal even after only a short exposure to a small amount.

D. Explosive: The GHS pictogram for an explosive substance is a diamond containing a bomb undergoing an explosion