The legal blood alcohol concentration (BAC) limit for driving in Texas is:

• 0.08% BAC for drivers aged 21 and older. If a driver’s BAC is 0.08% or higher, they are considered legally intoxicated and can be charged with driving while intoxicated (DWI)

• 0.04% BAC for commercial drivers (CDL holders). This stricter limit reflects the greater responsibility and risk involved in operating commercial vehicles

• Zero tolerance for drivers under 21. It is illegal for anyone under 21 to operate a vehicle with any detectable amount of alcohol in their system (effectively a BAC of 0.00%). Even a BAC as low as 0.001% can result in license suspension or DUI charges for underage drivers

Texas law uses breathalyzer and blood tests to measure BAC, with breathalyzers providing estimates and blood tests being more accurate but requiring a warrant

. In summary:

Driver Category| Legal BAC Limit
---|---
Age 21 and older| 0.08%
Commercial drivers| 0.04%
Under 21 (zero tolerance)| 0.00% (any detectable alcohol)

These limits are enforced strictly, with severe penalties for violations including fines, license suspension, and possible imprisonment