In California, it is simply implied that you consent to alcohol tests. California is one of several states that have implied consent laws, and these laws hold that you consented to a chemical test for the presence of alcohol in your system, performed in the event that police officers suspect you of driving under the influence of alcohol. Under implied consent laws, you are considered to have given your consent for such tests at the time of obtaining your driver’s license.
Therefore, in California, you're eligible for penalties if you refuse to provide samples for a test. You can however choose to have a breath test, or blood test. If neither blood nor breath tests are available, then you may have to take a urine test. Typically, you may first be asked to take a breath test, and after that, you may have to submit to a blood test to confirm the evidence.
You can tell the officer that you refuse to take the test, but the officer must explain to you that your refusal to take the test makes you liable for penalties, including loss of your license. You will also be sent to jail for refusal, if you're later convicted of DUI.
Should you agree to take an alcohol test?
Refusal to take an alcohol test can come with stringent penalties. In California, you could be sentenced to a one-year suspension of your license, and if this is the second time that you have refused a test, you could lose your license for a period of two years. Also understand that because you have refused to take the test, does not mean that you will not be convicted for DUI. You could find yourself convicted of both charges.