What occupancy category should be used for structures producing highly toxic materials?

The correct choice of occupancy category for structures producing highly toxic materials is High-Hazard group H-4. This classification is specifically designed to address the unique risks and safety concerns associated with the storage, use, and handling of materials that can pose significant health hazards.

High-Hazard group H-4 is designated for buildings where the materials being handled can pose a serious threat to safety due to their toxicity, particularly when they have the potential to cause harm to individuals even in small quantities. This category includes structures where toxic gases, fumes, or substances are produced, stored, or utilized. The stringent safety and construction requirements associated with H-4 reflect the need to minimize exposure and ensure safety protocols are in place, which is critical for public health and safety.

In contrast, residential groups like R-3 are primarily designed for homes and multifamily housing, commercial groups like B pertain to business practices not involving high hazard materials, and industrial groups like F focus on moderate processing and manufacturing but do not specifically account for the potential dangers of highly toxic materials. Therefore, H-4 is the most appropriate designation for ensuring safety in structures that manage highly toxic substances.