Food safety

Global Environment Monitoring System - Food Contamination Monitoring and Assessment Programme (GEMS/Food)

Last reviewed/updated
20 June 2013

Introduction to GEMS/Food

Since 1976, the Global Environment Monitoring System - Food Contamination Monitoring and Assessment Programme, which is commonly known as GEMS/Food, has informed governments, the Codex Alimentarius Commission and other relevant institutions, as well as the public, on levels and trends of contaminants in food, their contribution to total human exposure, and significance with regard to public health and trade. The programme is implemented by the WHO in cooperation with a network of more than 30 WHO Collaborating Centres and recognized national institutions located all around the world.

The GEMS/Food programme also involves national experts in more than 100 countries working to collect and to analyse data and information to support the food risk assessment process.

Several important streams of data related to food consumption and food contamination are included in GEMS/Food:

  • Per capita food consumption: As part of its dietary exposure assessment mandate, GEMS/Food has developed supra-national model diets which are currently used for predicting dietary intake of various chemicals according to internationally accepted methodologies (EHC 40). GEMS/Food Diets are based on per capita data compiled by the Food and Agriculture Organization of the United Nations (FAO). These data provide statistics on a country's annual food production, imports and exports and are accessible through the FAO web site: FAOSTAT .

The GEMS/Food Consumption Areas are based on geographic proximity between countries. The GEMS/Food Cluster Diets are based on similarities between dietary patterns. For example Australia is in the same consumption area than Japan but in the same cluster diet than Great Britain. This means that these model diets should be used for specific purpose and are not interchangeable.

  • Individual food consumption: Table that compiles individual levels of food consumption for average and high consumers based on national surveys. This information is used mainly to assess exposure to food chemical presenting a potential acute risk for human health.
  • Concentration of chemicals in food: Database on the level of chemicals in raw food commodities as well as in food as consumed by final consumer.

Food contamination monitoring is an essential component of assuring the safety of food supplies and managing health risks at the international level. The GEMS/Food database is open to Competent Authorities to submit and share their data on food surveillance and monitoring.

Data is checked for consistency and completeness before being accepted by WHO and as such, GEMS/Food provides reliable information on hazard identification for setting priorities for Codex consideration.

Within the Codex Alimentarius Commission, the chemical contamination of food is addressed by the Codex Committee on Food Additives (CCFA), the Codex Committee on Contaminants in Food (CCCF) and the Codex Committee on Pesticide Residues (CCPR). Risk management decisions are highly dependent on comparable and reliable exposure assessments and GEMS/Food has provided assistance on a range of chemical issues to CCFAC and CCPR as well as to their scientific advisory bodies, namely JECFA and JMPR.


GEMS/Food Database - 2011 Update

  • GEMS/Food Database
    This is a web-based system to access and submit data on contaminant levels in foods (OPAL-web) established in 2011.
  • GEMS/Food Database manual
    pdf, 436kb

    This manual presents protocols for submitting individual and aggregate data on contaminant levels in foods through OPAL-web.