 More generally , some scientific researchers have expressed objective concern over certain ingredients sometimes added to condoms , notably <unk> and <unk> . Dry <unk> <unk> are applied to latex condoms before packaging to prevent the condom from sticking to itself when rolled up . Previously , <unk> was used by most manufacturers , but <unk> is currently the most popular <unk> powder . <unk> is known to be toxic if it enters the abdominal cavity ( i.e. , via the <unk> ) . <unk> is generally believed to be safe ; however , some researchers have raised concerns over its use as well . 
