Blood alcohol level (BAC), is the amount of alcohol in your blood that develops from drinking beverages that contain alcohol. Levels can range from 0% (no alcohol) to over 0.4% (a potentially fatal level).

Here’s how different percentages of blood alcohol content (BAC) can affect you physically and mentally:

• BAC 0.0%: There’s no alcohol in your blood (you’re sober).
• BAC 0.02%: At this percentage, you may experience an altered mood, relaxation and a slight loss of judgment.
• BAC 0.05%: At this percentage, you may feel uninhibited and have lowered alertness and impaired judgment.
• BAC 0.08%: At this percentage, you may have reduced muscle coordination, find it more difficult to detect danger and have impaired judgment and reasoning.
• BAC 0.10%: At this percentage, you may have a reduced reaction time, slurred speech and slowed thinking.
• BAC 0.15%: At this percentage, you may experience an altered mood, nausea and vomiting and loss of balance and some muscle control.
• BAC 0.15% to 0.30%: In this percentage range, you may experience confusion, vomiting and drowsiness.
• BAC 0.30% to 0.40%: In this percentage range, you’ll likely have alcohol poisoning, a potentially life-threatening condition, and experience loss of consciousness.
• BAC Over 0.40%: This is a potentially fatal blood alcohol level. You’re at risk of coma and death from respiratory arrest (absence of breathing).

It's important to note that the effects of alcohol can vary depending on a number of factors, including age, gender, weight, and the amount of food consumed before drinking.

The legal drink-driving limit in Singapore is strictly enforced at 80 milligrams per 100ml of blood, or 0.08% blood alcohol content. If your breath alcohol content is more than 35 micrograms of alcohol per 100ml of breath, or you are under the limit but appear to be out of control in your vehicle, you can still be criminally charged.