I'm really confused by the "sanitising" comment - I understand "engineered" to refer to the whole manufacturing process, the fact that it resembles and function

I'm really confused by the "sanitising" comment - I understand "engineered" to refer to the whole manufacturing process, the fact that it resembles and functions similarly to "raw" solid wood but has been broken down and rebuilt with different properties (of which fire-resistance is just one). What would be a better name? Is "pressure-treated" sanitized because it doesn't really convey what chemicals are involved? I'm having a hard time envisioning how the general name for this class of products would be expected to better reflect the potential presence of fire-retardant chemicals.