Blood Alcohol
Blood Alcohol Concentration (BAC) refers to the amount of alcohol in the bloodstream. It is expressed as a percentage of ethanol to blood in the human system. This ethanol is expressed in grams and BAC is calculated as a proportionality of masses, ethanol to blood, or mass of alcohol per volume (100ml) of blood.
BAC can be measured by blood, breath or urine tests. It is mostly used as a metric of alcohol intoxication for legal or medical purposes.
Estimated Blood Ethanol Concentration (EBAC)
In order to estimate a calculation for the amount of alcohol within a system, the Widmark formula is used. It is important to notice that a number of factors influence the behaviour of alcohol in a system, such as gender, weight and metabolism. The formula states that to calculate an approximation for the blood alcohol in grams per decilitre (g/dL), one must:
-
Multiply the constant of water (which is 0.806), the convertor to Swedish standards (which is 1.2), and the number of drinks consumed containing 10g of ethanol (SD).
-
Divide the previous answer with the Body Water (BW) constant (0.58 for men, and 0.49 for women) multiplied by weight (WT).
-
Substitute the Metabolism Rate (MR) of elimination (0.015 for men, and 0.017 for women) multiplied by Time (in hours), from the previous answer.
In standard form:
The formula shows that for an average man and woman of the same weight, that drink the same amount of alcohol in the same amount of time, the blood alcohol in women would be slightly greater.
Considering a man and a woman, each weighing 70kg, drinking 3 portions of alcohol within 2hours. Inserting all variables in the formula above, we get:
EBAC (of man) = ((0.806 * 3 * 1.2) / (0.58 * 70)) - (0.015 * 2) = 0.41468 g/dL
EBAC (of woman) = ((0.806 * 3 * 1.2) / (0.49 * 70)) - (0.017 * 2) = 0.50595 g/dL
In Malta, as in most countries in the world, one is illegally intoxicated if blood alcohol level exceeds that of 0.08%, no matter the age.
BAC - Level Effects
There are 8 BAC Level Stages. As a person continues to drink and increase the alcohol intake, the BAC level also increases and the effects are more severe.
 No loss of coordination, slight euphoria and loss of shyness. Relaxation, but depressant effect are not apparent. |  Feeling of well being, relaxation, lower inhibitions, and sensation of warmth. Euphoria. Some minor impairment of judgement and memory, lowering of caution. |
|---|---|
 Slight impairment of balance, speech, vision, reaction time, and hearing. Euphoria. Reduced judgement and self-control. Impaired reasoning and memory. |  Significant or gross motor impairment and loss of physical control. Blurred vision. Euphoria reduces and dysphoria begins (a state of feeling unwell). |
 Dysphoria predominates, nausea may appear. The drinker has the appearance of a sloppy drunk. |  Needs assistance in walking, total mental confusion. Dysphoria with nausea and vomiting, possible blackouts. |
 Alcohol poisoning. Loss of consciousness. |  Onset of coma, possible death to respiratory arrest. |
A study showed that alcohol in carbonated beverages is absorbed faster than that in non-carbonated ones. Another study showed that sparkling substances also show greater blood alcohol levels when compared to that of non-sparkling ones (which approximates 15mg).