Are you a North Carolina resident that an officer pulled over? If officers suspect you are driving under the influence, they may ask you to take a blood alcohol content (BAC) test. The blood alcohol test is particularly reliable, but is it infallible?

The National Institutes of Health examine different types of BAC level tests. Lab technicians will take a sample of blood for the blood alcohol test. This blood is then examined by a lab, who test for your BAC level. This test is often praised for having fewer variables involved that could skew results. But this does not mean they are lacking in risky variables.

For example, there have been instances of human error where lab technicians swap results or samples. This is a risk with overstaffed and overworked labs. Samples can become contaminated if technicians are not careful. If the samples are not properly cared for before testing, it can change the results.

Next, your body may work against you. For example, certain diets or diseases can cause BAC levels to look high when you have not had alcohol. Diabetes, high ketones, cough or cold medication and even cough drops can all make your BAC levels look higher than they are. Additionally, it takes a while for alcohol to get into your blood stream.

There have been cases where a person’s BAC level was under the limit when the police arrested them. By the time a technician was able to draw their blood, it was over the limit. However, they were still driving while under the limit. These are important distinctions to know.