Here is Cassandra Dunn, a Registered Nurse, and certified Federal Medical Investigator/Healthcare Surveyor. Here she succinctly describes what is in the nasal swabs, and why you should not get nasal-swab tested. Visit her website at https://purplelionproject.com, where in her blog she has other videos of interest.

Citations :
1) Frequent Questions: Health Information About Ethylene Oxide - https://www.epa.gov/hazardous-air-pollutants-ethylene-oxide/frequent-questions-health-information-about-ethylene-oxide
2) Ethylene Oxide ; CAS No. 75-21-8 - https://ntp.niehs.nih.gov/ntp/roc/content/profiles/ethyleneoxide.pdf
3) CCOHS Fact Sheet on Ethylene Oxide - https://www.ccohs.ca/oshanswers/chemicals/chem_profiles/ethylene_oxide.html

Ningbo HLS Medical Products - https://www.cnhlsmedical.com/swab/disposable-sampling-swab/sampling-flocked-swab.html
Miraclean Technology Nasal Swab - https://www.mantacc.com/nasopharyngeal-sampling-swabs-15936872289228819.html