The National Institute of Alcohol Abuse and Alcoholism has come up with levels that define low-risk drinking for the average man and woman. This risk is primarily damage to the body as a direct result of alcohol circulating in the system. It does NOT include behavioral consequences. For example, it would not be safe for many people to drink and drive after drinking the amounts listed.
For men, the limit is no more than 14 drinks per week and no more than 4 drinks on one occasion. So, Sam cannot save his 14 drinks until Saturday night and drink them all at once!
For women, the amount is much lower; 7 drinks per week and no more than 3 on one occasion. For many physiological reasons, women do not process alcohol as well as men and have increased medical risks from drinking alcohol.