38-400 Solvent Extraction Caps
As part of the Glass Packaging Institute (GPI) standards, the 38-400 thread type has become a cornerstone of modern packaging. Widely used across various industries, it appears in products such as spice jars, kombucha bottles, and cooking oil. In laboratory settings, it is trusted by brands like Wako Chemical for its airtight seal and dependable chemical storage.
The 38-400 thread is also a common feature of plastic bottles, including 5L “Space Savers,” Cubitainers, and 1-gallon F-style industrial jugs. Originally developed in the mid-20th century to standardize industrial packaging, it quickly became a preferred choice for its balance of security, reusability, and convenience. Whether safeguarding laboratory chemicals or keeping pantry items fresh, this simple yet innovative design continues to demonstrate the enduring impact of thoughtful engineering.
Integrated evaporation control
All Lab Lids safety caps for solvent extraction include ported inserts—threaded ports designed for secure tubing connections.
For integrated evaporation control, choose caps with built-in check valves that regulate airflow in a single direction. These valves allow air into the bottle to prevent vacuum buildup while solvents are pumped to the instrument.
Check valves are available in three material options based on chemical compatibility needs. Each seal material is color-coded by the particulate filter at the center of the cap:
FFKM for nearly universal compatibility (yellow filter color)
FKM (green filter) and EPDM (blue filter) for cost-effective alternatives with a narrower compatibility range.
