The actual chemistry of hand sanitizers is what really helps define if they are effective against infections. If they have key ingredients such as types of alcohol (about 60 percent at least), chlorhexidine, and benzalkonium chloride – then they are effective at fighting off viruses and bacteria. So check the components of the hand sanitizers you buy. And as long as you use it liberally – a palmful — and cover all parts of your hand and keep using it as often as possible.