Where THF is used
INRS lists solvent applications for resins and plastics, adhesives, inks and coatings, alongside laboratory work and chemical synthesis. Identify CAS number 109-99-9 in the formulation. Exposure assessment needs to establish whether use is enclosed, involves surface application or requires open containers. The quantity purchased alone does not describe these differences or identify who is exposed during each stage.
Vapour and contact
THF is highly volatile and readily flammable. It can cause irritation and affect the central nervous system; repeated contact also damages skin. Smell cannot establish a safe concentration. Connect tasks with release sources, proximity and duration, including cleaning and waste removal. These activities may be absent from routine production descriptions even though workers approach open solvent or contaminated equipment.
Peroxides need separate management
Contact with air can produce unstable peroxides, with light and heat favouring formation. Some commercial products are stabilised, but this does not make storage indefinite. Solvent concentration or recovery needs specialist assessment. Do not handle suspect containers or improvise testing or treatment: competent personnel must use procedures specific to the product and laboratory, including appropriate arrangements for disposal.
An inventory that supports decisions
Record supplier, formulation, receipt, opening and storage conditions according to the established procedure. An old container without traceability presents a different decision from newly supplied, identified material. Stock and waste management should reveal that difference before use. Avoid setting a universal storage period without manufacturer information and assessment of actual conditions; stabilisation and documented storage history should be considered together.
Control the actual operation
Prioritise contained transfer and suitable capture wherever release occurs. Check seals, containers and protective-material compatibility because THF can affect certain plastics. In laboratories, include repeated small operations and waste left open between tasks. Select supplementary protection for the mixture and activity; the presence of a general-purpose glove is not evidence of adequate chemical resistance during contact.
Verify and review
Sampling should represent relevant operations and distinguish THF from other solvents present. Retain temperature, use and active-control information with results. Reassess emissions and incompatibilities when the process changes. Consult current sources for toxicological information and applicable classifications; historical sheets should not become a universal table of exposure limits. A good exposure result also does not certify the chemical condition of stored stock.
