IACS releases revised and new Unified Interpretations on ventilation and SOLAS regulations

The International Association of Classification Societies (IACS) has recently released two Unified Interpretations: an updated version of UI SC89 concerning the ventilation of cargo spaces, and the newly introduced UI SC301 regarding SOLAS regulations II-2/9.7.2 and 9.7.5.1 – separation of ducts from spaces.

The revised UI SC89 will come into effect on January 1, 2025, while the new UI SC301 is scheduled to take effect on July 1, 2025.

Ventilation of Cargo Spaces

The document outlines ventilation requirements for cargo spaces. It mandates adequate power ventilation, ensuring at least six air changes per hour. Ventilation systems must remove vapors and prevent ignition of flammable gas mixtures, with openings fitted with wire mesh guards. Natural ventilation is required for solid dangerous goods. Continuous ventilation is needed for certain cargoes like aluminum powders and zinc ashes. Guidelines for ventilation design are provided along with implementation dates for document revisions.

SOLAS Regulations II-2/9.7.2 and 9.7.5.1 – Separation of Ducts from Spaces

The document outlines SOLAS regulations concerning the separation and construction of ducts on ships. For spaces like machinery areas and galleys, ventilation systems should be separated, with specific provisions for smaller cargo and passenger ships. Ducts must meet stringent construction standards, including steel construction, fire dampers, and insulation to "A-60" class. Additional requirements apply to passenger ships, especially concerning galley exhaust ducts, including fire safety measures and grease removal systems.

For more information, please see the documents below (available only to subscribers):

Ventilation of Cargo Spaces

SOLAS Regulations II-2/9.7.2 and 9.7.5.1 – Separation of Ducts from Spaces