The answer is hand washing. Milady's phrasing is direct: "Hand washing is the first step in maintaining good hygiene." It's placed first for a practical reason — a barber's hands touch every client, every implement, and every surface in the shop, so hand hygiene is the single highest-leverage habit for preventing the spread of the bacteria and viruses covered elsewhere in the Sanitation chapter.
Not smoking during work hours, using mouthwash, and brushing your teeth — the other choices — are all reasonable personal-hygiene practices, but none of them is the specific "first step" Milady names; hand washing is the one the textbook singles out as foundational.
Milady Standard Barbering, 6th ed., Ch. 3 (Your Professional Image), p. 41: "Hand washing is the first step in maintaining good hygiene."
This is 1 of the real Sanitation questions in FadeJunkie's Milady-sourced 300-question bank. See the Sanitation practice questions page for a fuller sample, or try the Sanitation practice quiz and flashcards for free. A one-time $15 lifetime pass unlocks the complete question bank across all 13 tested topics.
More real Sanitation questions with sourced answers: What Does Staph Bacteria Cause, What Disease Do Diplococci Cause, What Category Do Disinfectants Fall Under, What Organ Does Hepatitis Damage, and 15 more on the Sanitation practice questions page.
Browse every topic on the Practice Question Hub, or see the Texas Barber State Board Exam Guide for the full exam process — required hours, PSI scheduling, and fees.