Within the operating costs of a chemical plant, which item is a direct component of utilities cost?

Introduction / Context:
Utilities represent metered or consumable services needed to run unit operations. Separating utilities from overhead helps allocate costs accurately to products and lines, improving pricing decisions.

Given Data / Assumptions:

• Utilities include steam, electricity, fuel gas, cooling water, process water, instrument air, nitrogen, etc.
• Support services like labs or security are overhead/general expenses, not utilities.

Concept / Approach:
Utilities cost must be directly traceable to consumables that power or condition processes. Water supply (make-up and cooling) is a textbook example of a utility. By contrast, laboratory, security, and medical services are support/overhead costs.

Step-by-Step Solution:
1) List candidate items and classify them as consumable utility vs. overhead.2) Water supply clearly qualifies as a utility consumed in processing and heat removal.3) Control lab, property protection, and medical services are plant overhead or general services.

Verification / Alternative check:
Typical utility bills and internal metering for water, steam, and power validate their inclusion as utilities in operating cost reports.

Why Other Options Are Wrong:
Control laboratory: quality/analytical overhead.
Property protection: security/overhead.
Medical services: HR/overhead.
Corporate advertising: selling expense, not a utility.

Common Pitfalls:
Charging shared overheads to utilities; proper cost segregation avoids distorting product unit costs.

Final Answer:
Water supply (process water and cooling water)