The Guideline for Quantitative Risk Assessment known as The Purple Book as part of the Publication Series on Dangerous Substances (Publicatiereeks Gevaarlijke Stoffen – PGS). (link)
This publication (also known as the 'purple book') describes calculation methods for performing risk calculations. Together, the 'red book' (PGS 4: probabilities), the 'yellow book' (PGS 2: effects), the 'purple book' (PGS 3: Quantitative Risk Analysis) and the 'green book' (PGS 1: damage) formed the series of standard works for risk analyses.
Please note that the coloured books will in principle no longer be updated, but will remain available for the time being as a historical reference work.
The file is available in Portable Document Format (PDF) which can be read from common PDF reader.