An international data base of exposure measurements in the pulp, paper and paper product industries was constructed to be used in exposure assessment for epidemiology studies and hazard control. Industrial hygiene and biological monitoring data were collected from countries participating in the multicentric study of the International Agency for Research on Cancer. Each measurement was characterized by country, mill type and number, department, job, agent measured, sampling method, measurement result in the standard unit, duration and date of sampling, assessment of representativeness, measurer, purpose of measurements, and remarks (e.g. on measurement sites and biases). Over 31,000 measurement results on 246 different chemical agents from 13 countries were available from pulp (45% of measurements), paper/paperboard/recycling (12%) and paper product (11%) mills or from their non-production departments (23%). Most measurements (82%) were carried out after 1980. The most frequently measured group of agents was inorganic gases (35%), followed by organic compounds (25%), solvents (18%), mineral dusts (12%), metals (6%) and bioaerosols (3%). Over 90% of the measurements were without an obvious bias, but their true representativeness is difficult to assess. Concentrations of various agents, including sulfur dioxide, chlorine dioxide, carbon monoxide, nitrogen dioxide, ozone, ammonia, formaldehyde and some solvents, often exceeded current occupational exposure limits. This data base summarizes a great deal of previously unpublished exposure data, provides a unique opportunity to study exposure patterns at the international level and identifies exposure situations that require further attention and investigation.