Alcohol Impairment

"Alcohol has a range of psychomotor and cognitive effects that increase accident risk on reaction times, cognitive processing, coordination, vigilance, vision and hearing, even at low blood alcohol levels. For these reasons alcohol consumption is normally closely regulated in relation to the operation of transport systems and other safety sensitive environments and activities.

"Adverse effects on vision have been found at blood alcohol concentrations of 30mg ethanol per 100ml blood, and the psychomotor skills required for driving have been found to show impairment from 40mg/100ml (in the UK the legal blood alcohol limit for drivers is 80mg/100ml). Raised risk of accident can also remain for some time after drinking, as skills and faculties do not necessarily return to normal immediately even once all alcohol has left the body. Drink-driving vehicles in general is a dangerous activity, as the number of alcohol-related serious injuries and deaths on Great Britain’s roads demonstrates. Since 2010, 4% – 5% of all reported road traffic accidents involved at least one driver over the drink drive limit have accounted for around. Between 13% – 16% of all deaths on GB roads over the same period did so too.1

"Impairment of faculties can also have a dangerous effect on the control of aircraft. In a study of airline pilots who had to perform routine tasks in a simulator under three alcohol test conditions, it was found that:

"• before the ingestion of any alcohol, 10% of them could not perform all the operations correctly;

"• after reaching a blood alcohol concentration of 100mg/dl, 89% could not perform all the operations correctly;

"• and 14 hours later, after all the alcohol had left their systems, 68% still could not perform all the operations correctly.2"


Institute of Alcohol Studies. Alcohol-related accidents and injuries. Oct. 2020.