Can ETG tests really go back 5-7 days?

I just started a alcohol program and the lab people there say their ETG tests can detect Alcohol as far back as 5-7 days. I’ve been doing a little research and I cant find anything online thats says anything more than 80 hours at the most with heavy drinking. I know the smart choice would to not chance it but I fear I might slip up from time to time. Is their anyone who has information on this or experience? Are these people just telling me that? This is my first post to reddit so not sure if I did this right.