Two routes of exposure
NOM-024-STPS-2001 is listed as current in the Mexican catalogue. It addresses vibration transmitted to the whole body and to the upper limbs. These assessments are not interchangeable: transmission points, axes, frequencies and assessment criteria differ between them.
Vibration exposure requires examination of actual work. A tool and a vehicle may produce figures expressed in similar units, but comparison requires knowledge of method, weighting and duration. Mexican criteria should not automatically be replaced by values from another jurisdiction.
Recognise sources and work cycles
The preventive programme includes recognition, assessment, training, health surveillance and control, with supporting records. Recognition identifies machines, tools, procedures, maintenance, people and exposure times. That information supports selection of the appropriate measurement method.
For example, a driver may encounter different surfaces and speeds during a shift. Measuring only on the smoothest section does not necessarily describe exposure. For hand-held tools, the activity, equipment condition and actual operating time are important to the assessment.
Measurement and changing conditions
Assessment takes place under normal operating conditions and covers the identified work cycles. Instruments and calibration must support correct measurement of the required quantities. The report needs to retain the circumstances that made its findings meaningful and representative.
The text requires reassessment at least every two years when below the limits, or sooner when changes to tasks, tools, equipment or areas may increase exposure. An old report does not continue to represent the job after a relevant modification.
Verified controls and follow-up
Measures include maintenance, equipment or process replacement, reduction at source, transmission isolation and time organisation. They need technical justification and verification after implementation without creating additional hazards. The standard requires annual training for exposed personnel.
Health surveillance follows the programme and appropriate medical judgement. Documentation retains information from the previous five years. This entry does not establish a safe operating duration for a particular tool or diagnose symptoms. It supports management that connects measurement, exposure reduction and follow-up of the people affected, rather than treating completion of a measurement report as the end of prevention.
