Which of the following best describes the origin of flexible-film isolators?

• A. 1950s
• B. 1940s
• C. 1960s
• D. 1970s

Answer: (A)

Flexible-film isolators first emerged in the 1950s as a practical solution for providing a barriered, controlled environment for animals without building a large, rigid structure. Advances in plastic film technology, sealing methods, and glove-access design made it possible to create portable, cost-effective containment that could be used to protect both the animals and the people handling them. While these systems were refined and more widely adopted in the 1960s, their origin is in the 1950s, which is why that decade is the best match. The 1940s didn’t yet have the mature film-based barrier technology, and by the 1970s the concept was well established, not just starting.