Drinkaware has very important details on their website regarding drinking in all capacities. Key points in the site are the effects of alcohol, what is the safe number of units to consume and when you should avoid drinking totally. There is also a section that explains the law with drinking in U.K. More information can be gained on the website link below or if you are living in the U.K call 0800 917 8282 (open 24 hours).
When you are visiting the site please take the reader survey as important information can be gained on the treads of consumers and the amount of alcohol that is being consumed. Within the links' page there are a number of excellent links regarding safe drinking and what drink effect can have on the our bodies.