School not at fault, its principal insists

Some chemicals reportedly found

Chlorobenzene

A colorless, flammable liquid. It was used to produce DDT from the 1940s to 1960s. It can affect the central nervous system and irritate skin and mucous membranes. May cause kidney damage. Humans may be exposed through air, food or water, or by contact with contaminated soil.

Carbon tetrachloride

A colorless liquid with a sweet smell that can be detected at low levels. Exposure to high concentrations can affect the central nervous system, harm the liver and kidneys and may result in coma or even death. Chronic exposure can result in cancer.

Carbofuran

A pesticide with the highest toxicity to humans of any chemical widely used on crops. One-quarter teaspoon (1 mL) can be fatal. China banned the use of carbofuran in October.

Source: ThePaper.cn