According to the North Carolina Driver's Handbook, your chances of being involved in an accident will increase once your blood alcohol concentration (BAC) reaches

If your BAC is 0.05% or more, your chances of a traffic accident will increase. At 0.05%, your coordination is reduced, your ability to track moving objects is reduced, your ability to steer is impaired, and your reaction time increases. Note that 0.05% is below the legal limit for driving while impaired (DWI). [Chapter 2: Alcohol and the Law, North Carolina Driver's Handbook], ["The ABCs of BAC," National Highway Traffic Safety Administration, https://www.nhtsa.gov/staticfiles/nti/pdf/809844-TheABCsOfBAC.pdf]