Yes — the 4-spoke base is completely safe and meets the same standards as the 5-spoke.
Both bases are independently tested to BIFMA (Business and Institutional Furniture Manufacturer's Association) standards for:
• Weight capacity up to 300 lbs
• Stability under normal seated use
• Long-term structural integrity
Will it tip over?
Under normal use — sitting, shifting, leaning — no. Like all office chair bases, it's not designed for standing on the chair or extreme lateral reaching. But for everything you'd normally do at a desk, it's stable.
4-spoke vs. 5-spoke stability
The 5-spoke has a slightly wider footprint, giving it a marginally larger stability zone. If you're very active in your chair, the 5-spoke is the slightly safer pick. For most users, there's no practical difference.
Check out a video highlighting the 4-Spoke base here.