ANFD systems are used throughout the HPAPI pipeline, both in intermediate and final product manufacturing. In either case, products with highly toxic payloads are discharged from a plug and need to be contained in an effective way, either before being looped back to an earlier phase of development or being filled into packaging containers. Conventional ANFD systems comprised a vessel with a piston valve that opened to discharge products, but such designs often require manual intervention due to residual product heel. Naturally, this wouldn’t satisfy current regulatory requirements for HPAPI manufacturing, nor would manufacturers wish to leave this heel behind as it could constitute hundreds or thousands worth of market value product. The plug needs isolating so that operatives are not exposed–but not all containment systems have been created in the same way.
One approach is to isolate the process using a flexible container, however, this would be unsuitable for any compounds classified above Occupational Exposure Band (OEB) 4. Greater containment requires not only a rigid isolator but also air management capabilities. A single chamber glove box with a negative pressure environment and added safety features may be suitable for HPAPI containment. Yet there are additional considerations to bear in mind beyond physical isolation and air management. A single chamber may have a packaging arrangement such as a continuous liner, rapid transfer port, or split valve technology. Another solution is a double chamber arrangement wherein the product is discharged into a primary chamber where it is packaged, before moving into a secondary chamber. This is a high-end but extremely effective solution for high containment performance. Lastly, the newest and most intensive approach to HPAPI manufacturing is total process isolation.