The **maximum blood alcohol concentration allowed** for non-professional drivers in general is **0.5 grams per liter**. This measure refers to the amount of alcohol present in each liter of blood after consuming alcoholic beverages.

- For non-professional drivers who have had their driving license for more than two years, the allowed concentration is **0.5 grams per liter of blood**. This is different for novice or professional drivers, who have lower limits due to the greater responsibility and risk associated with their driving.

- It is important to remember that, although this is the maximum allowed concentration, the only completely safe concentration for driving is **0.0 grams per liter**, meaning not having consumed any alcohol at all. Driving under the influence of alcohol can severely affect the driver's reaction and judgment, increasing the risk of accidents.

In summary, for most non-professional drivers, the limit is **0.5 grams per liter of blood**, and it is crucial to respect this limit to ensure road safety.