Identify the isomer
n-Butanol has CAS number 71-36-3. It should not be confused with isobutanol, sec-butanol or tert-butanol, which have different identities and properties. Purchasing, assessment and measurement records should use the name and CAS together. For mixtures, record components and concentrations. Do not select protection or reference values from an abbreviated butyl-alcohol label without confirming which substance and formulation are actually supplied.
Where exposure can occur
INRS lists paints, varnishes, cleaning, degreasing, extraction and synthesis uses. Surface application, mixture charging and component removal create different evaporation and contact conditions. Describe actual stages, including time between uses of an open container. Cleaning and waste tasks may involve more direct handling than production itself, and need to remain visible in the assessment rather than being treated as incidental activities.
Protect eyes and skin
The ILO/WHO sheet highlights serious eye damage and skin irritation; repeated contact may dry and crack skin. A brief pouring task needs splash assessment even when average airborne concentration is low. Review height, connections and container stability alongside supplementary protection. Dermal-exposure assessment should include the mixture and contact duration, rather than assuming that gloves alone resolve every possible contact.
Vapour and temperature
High exposure can affect the central nervous system. Heating and open surface area change release, so room-temperature volatility alone is insufficient. Agree measurements representing application, drying or cleaning as appropriate. Perceptible odour does not quantify exposure, and absence of drowsiness does not establish adequate control for every worker or every stage of the process in which the solvent is used.
Compatibility and alternatives
n-Butanol is flammable and may react dangerously with incompatible substances. Check equipment materials and process conditions. When substituting it, compare complete hazards and the replacement’s actual performance. An alternative requiring more heat, greater application area or additional manual cleaning may alter exposure in ways that are not evident from labels alone, even if one listed hazard appears less severe.
Verify the changed work
If closed dosing is installed, observe connection, removal and system cleaning too. Record product, temperature, workload and controls so results can be interpreted. Evidence should identify which task improved and which remains unresolved. Review current requirements and limits in the country of work; recommendations for another isomer or historical values should not become a general assurance of safe use under different conditions.
