Final answer:
Antiknock compounds in gasoline and new refrigerants in air conditioners and refrigerators were created due to environmental concerns, specifically the depletion of the ozone layer. Laws were passed to regulate these chemicals and promote a switch to safer alternatives.
Step-by-step explanation:
The need for antiknock compounds in gasoline and new refrigerants in air conditioners and refrigerators was created due to environmental concerns, particularly the depletion of the ozone layer. Certain refrigerants and aerosol sprays were found to be damaging the ozone layer, which led to laws mandating the use of different refrigerants and regulating the chemicals used in manufacturing. This was a global issue that led to UN initiatives like the Kyoto Protocol.