Chemicals that are harmful

There are chemicals that are harmful to humans include: 

a. Aluminum Sulfate (AlSO4) 

Shaped white crystals, soluble in water. Aluminum Sulfate is used instead of alum. 

b. Concentrated ammonia (NH4OH) 

Concentrated solution of ammonia gas in water, if exposed to skin and eyes may cause irritation. In vapor form can interfere with breathing apparatus. Concentrated ammonia is harmful if swallowed. 

c. Sulfuric acid (H2SO4) 

Sulfuric acid is a colorless liquid, toxic and highly corrosive. Sulfuric acid can cause burns to skin, eyes, and can damage clothes. 

d. Hydrochloric acid (HCl) 

Hydrochloric acid is a liquid, toxic, corrosive, and in the form of vapor can damage the skin, eyes, and breathing apparatus. 

e. Ethanol (C2H3OH) 

Ethanol is often called alcohol. Ethanol has the properties of flammable and used as a solvent. 

f. 40% formaldehyde (HCHO) 

Formalin is toxic, either liquid or gas. Formalin is used to kill pests. 

g. Chloroform (CHCl3) 

Chloroform is a colorless liquid and are toxic. Chloroform is used as an anesthetic in the laboratory. 

h. Metilin blue 

Metilin tangible solid dark blue. This chemical is used as the cell nucleus staining. 

i. Sodium hydroxide (NaOH) 

Sodium hydroxide is a white solid, easy to absorb moisture, air, toxic and corrosive. Sodium hydroxide include hazardous materials that may cause burns to skin and eyes. 

j. Cobalt chloride (CoCl6H2O) 

Cobalt chloride is a solid, red crystals, very easy to absorb water, and can bind water vapor. Cobalt chloride is used to test the air humidity. 

k. Sodium chloride (NaCl) 

Sodium chloride is a white solid, crystalline form. Sodium chloride is also often called salt.