he second issue is loss of performance with time. Studies have shown that high quality discs with a
BLER of only 2 per second can degrade to 700 per second after one year of office use, and to a BLER of 4,000 per second when the readout surface is heavily scratched.
ISO Standard 10149 requires BLER to be less than 220 for successful interchange, indicating that improper handling can cause a disc to fail in months or even weeks.