It is often not realised that the maximum permitted alcohol limit in Spain is considerably lower than many other European countries, including the UK.
It is also worth noting that these limits are precisely that, a maximum that is permitted. Alcohol affects people differently and the only real safe limit is zero.
That said, in Spain the maximum legally permitted alcohol limit is in general 0.25 mg/l (or 0.15 mg/l if you are a learner driver / professional drivers). If the amount of alcohol exceeds this limit, the driver will be heavily fined and lose several points from their licence.
In the event such amount of the breathalyzer exceeds 0.60 mg/l, the driver becomes subject to a criminal proceeding and will be arrested.
A blood test is only available when you have finished the alcohol test and you disagree with the result.
Refusal to co-operate is also considered a criminal offence.