Three exposures within one framework
Convention 148, adopted in 1977, concerns air pollution, noise and vibration in the working environment. It connects engineering prevention, work organisation, information and health surveillance, rather than treating each measurement as an isolated administrative exercise.
International obligations depend on ratification. The convention also permits separate acceptance of hazard categories, so the scope accepted by each State needs checking. Specific requirements are implemented through national legislation and practice rather than a universally identical workplace rulebook.
Limits set by the competent authority
The convention does not provide one worldwide table of numerical limits. It assigns the competent authority responsibility for criteria and, where appropriate, exposure limits, reviewed as knowledge develops. It also recognises increased risk from simultaneous exposure to several harmful factors.
The entry on physical agents at work helps distinguish assessment methods. Noise, vibration and airborne contaminants are not interpreted using the same unit or an undifferentiated environmental reading. Assessment needs to identify tasks, duration, equipment and representative operating conditions before drawing conclusions.
Control before reliance on personal equipment
Priority goes to engineering measures in new designs or existing installations, supplemented by work organisation where appropriate. Personal protection is provided where these measures do not bring exposure within applicable limits. It does not make an uncontrolled source a resolved problem.
For example, purchasing a quieter machine may reduce exposure at source. Installation and maintenance must preserve that benefit. Recommendation 156 adds guidance on checking newly introduced or modified equipment and on maintenance and calibration of measuring instruments.
Cooperation and follow-up
Where several employers share a workplace, the convention provides for cooperation without removing individual employer responsibilities. Workers and representatives should receive information, training and opportunities to participate. Health surveillance follows the relevant risks and national conditions, without cost to workers.
A preventive review should connect findings, controls and reassessment. Filing an old measurement campaign does not demonstrate that a changed process remains equally well controlled. This entry explains the international framework; it does not replace a task-specific occupational hygiene assessment or establish local numerical exposure limits.
