Ethylene Blocking Technologies 1-Methylcyclopropene (1-MCP). 1-MCP is the most widely used commercial volatile ethylene inhibitor, which blocks ethylene binding sites. Silver thiosulfate (STS). The use of this material is largely restricted to cut flowers and it is sold commercially under the trade name Chrysal AVB®. Aminoethoxyvinylglycine (AVG). This material is sold commercially as ReTain® and acts as a plant growth regulator by blocking the production of ethylene in the plant tissue