Benzyl chloromethyl ether is primarily used in organic synthesis as a reagent for introducing the benzyloxymethyl (BOM) protecting group. This protecting group is particularly useful in the protection of hydroxyl groups in alcohols and phenols during complex chemical reactions, ensuring that these groups remain unaffected while other parts of the molecule undergo transformation. It is commonly employed in the synthesis of pharmaceuticals, agrochemicals, and fine chemicals, where selective protection and deprotection of functional groups are crucial. Additionally, it finds application in the preparation of polymers and resins, where it can act as a cross-linking agent or a modifier to enhance specific properties of the material. Due to its reactivity, it is handled with caution in controlled environments to avoid unwanted side reactions or hazards.