Since 1996, the state of California requires all acupuncture needles to be Sterile and Single-Use.
These needles also have a small handle to reduce risk of infections, prevent the needles from traveling too far into the body, and to ease the removal of the needles.
There are risks of serious side effects with Acupuncture, but they are very uncommon. Acupuncture has been monitored globally since 1980, and since then not only have there been very few incidents, the rate has gone down with each passing year due to improvements in materials and increased safety training.
See Shifen Xu, et al (2013) for detailed safety analysis: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3616356/
California acupuncturists are regulated by the department of consumer affairs. You can learn more about them here: https://www.acupuncture.ca.gov/