Scope of the instruction
MIE APQ-6 forms part of Royal Decree 656/2017 and concerns corrosive liquids stored in fixed containers in Spain. Applicability depends on liquid classification, quantities and specified exclusions. Assess the product under actual storage conditions, not merely by its trade name. General chemical storage organisation is supplemented here by dedicated technical requirements.
Certain process storage arrangements are excluded from parts of the scope, but loading and unloading facilities may remain subject to the instruction. Each operation therefore needs to be defined rather than declaring an entire continuously operating factory exempt.
Compatibility throughout service life
A material resistant to a substance is not necessarily suitable at another concentration or temperature. The design needs to justify materials, anticipated corrosion and service life. For lined tanks, ageing, adhesion and lining characteristics also matter. Checking only the outside wall leaves part of the risk unexamined.
The ministerial guide connects periodic reviews to defined necessary thicknesses or a documented service life. A lack of visible corrosion does not demonstrate that equipment without design records remains suitable. Technically competent personnel need to assess it using verifiable acceptance criteria.
Prevent releases and their consequences
Review filling arrangements, level monitoring, overfilling, connections, pipework, containment and potential leak routes. The protective arrangements must be compatible with the liquid. A bund that collects incompatible products together may create an additional reaction instead of limiting damage.
Access, signs and relevant decontamination facilities also need checking. Emergency equipment requires maintenance and real availability: a shower blocked by stored materials cannot perform its function merely because it appears on the project drawing.
What changes when the product changes
For example, increasing an acid’s concentration may require reassessing the tank, seals, pipework and operating conditions even when tank capacity is unchanged. Compare each modification with the technical file before use and retain the maintenance records. APQ-6 does not replace workplace exposure assessment, personal protection selection or spill response procedures. Those decisions require the actual chemical and scenario, with responsibilities assigned before operations begin rather than relying on a generic description of corrosive hazards.
