Nonoxynol 9. Packages should be clearly labeled "spermicidal lubricant". Read labels carefully.
Nonoxynol 9. Packages with nonoxynol 9 should be clearly marked "spermicidal lubricant".
Variety, but. You need to read packages carefully. Look for one not marked "spermicidal lubricant".
No. Spermicide coated condoms do not break easily if used correctly. Remember they must be stored safely too. Keeping them in your car or in a hot location can cause the material to break down. Also never use one passed the expiration date.
Surfactant. Nonoxynol9 is a surfactant. That means it breaks down surface integrity of fluids (like the membranes of sperm or vaginal lining). It has spermicidal activity. But there is some question as to whether it increases risk of HIV in heavy users by an unknown mechanism. Who has declared it unsafe. Many condom manufacturers have discontinued using it in condoms.
No. The easiest way would be to expose yourself to it.