For example, for the Gases under pressure hazard class, the hazard categories are Compressed gas, Liquefied gas, Refrigerated liquefied gas and Dissolved gas. These classes relate to the physical state of the gas when packaged and do not describe the degree of hazard.
1 In 1596, a flush toilet was invented and built for Queen Elizabeth I by her Godson, Sir John Harrington. 2  The first patent for the flushing toilet was issued to Alexander Cummings in 1775. 3  During the 1800s, people realized that poor sanitary conditions caused diseases.
Joseph C. Gayetty (b. 1827? Massachusetts - d.__ ) was an American inventor credited with the invention of commercial toilet paper. It was the first and remained only one of the few commercial toilet papers from 1857 to 1890 remaining in common use until the invention of splinter-free toilet paper in 1935 by the Northern Tissue Company.