This Peroxide is NOT what you associate with bleached blonds. It is a chemical measurement that indicates the freshness of olive oil. To qualify as Extra Virgin olive oil this level must be less than 20%. The lower the better and fresher. More info here.
The Acidity level is also a measure of freshness. It is completely tasteless and is a chemical description of the extent the oil has been oxidized, or exposed to oxygen. To qualify as Extra Virgin olive oil the level must be less than 0.8 degrees. Again the lower the better and the fresher. Refined oil is the exception to this rule as the refining process (watch the refining process), which destroys all the health benefits in olive oil, also reduces the acidity level to extremely low levels.
When you have both the Acidity and Peroxide levels you have a duo confirmation of the quality and freshness of the Extra Virgin olive oil.