If you are concerned about fire, it is prudent to store flammable materials in a fireproof box.

It is preferable to use storage systems made of "archival" quality materials. Zip lock bags are not suitable for this purpose. For instance, they can trap moisture.

Use of a dehumidifier should be avoided because they use heat to draw moisture from the air. Heat can accelerate degradation of your film and photographs. However, it would be a good idea to use a desiccant, such as silica gel packs. To ensure that they continue to work, they should periodically be replaced or regenerated by heating.

If you are concerned about fire, it is prudent to store flammable materials in a fireproof box. If you are in an area prone to flooding, you might consider keeping your film and photographs offsite (perhaps in a bank safe deposit box).

It is preferable to use "archival" quality storage systems. Zip lock bags are not suitable for this purpose. They can also trap moisture.

Use of a dehumidifier should be avoided because they use heat to draw moisture from the air. Heat can accelerate degradation of stored materials. However, it is a good idea to use a desiccant, such as silica gel packs. To ensure that they continue to work, you should periodically replace or regenerate them. You can regenerate them by heating them for a few minutes. Let them cool before reuse.