What type of sealant should not be used on surfaces exposed to cargo?

Butyl sealant is not recommended for use on surfaces exposed to cargo due to its properties that may lead to degradation when in contact with certain cargo materials. Butyl sealants are known for their excellent adhesion and flexibility, but they can be permeable to some chemicals found in various cargoes. This permeability can compromise the integrity of the seal and potentially lead to contamination of the cargo or damage to the container. Additionally, certain cargoes, especially those that are aggressive or reactive, can cause butyl sealants to break down, reducing their effectiveness over time.

In contrast, silicone, polyurethane, and chloroprene sealants typically offer greater resistance to moisture and chemicals, making them more suitable for use in environments where they will be in contact with various types of cargo. These alternatives provide better durability and longevity, ensuring that containers remain sealed effectively without compromising the cargo within.