Changes made by 1999/391/EC: Commission Decision of 31 May 1999 concerning the questionnaire relating to Council Directive 96/61/EC concerning integrated pollution prevention and control (IPPC) (implementation of Council Directive 91/692/EEC) (notified under document number C(1999) 1395)
EU Decision 1999/391
No changes made by 1999/391/EC: Commission Decision of 31 May 1999 concerning the questionnaire relating to Council Directive 96/61/EC concerning integrated pollution prevention and control (IPPC) (implementation of Council Directive 91/692/EEC) (notified under document number C(1999) 1395) are recorded.
From legislation.gov.uk's record of changes, the official one: see it there.