Introduction: The effects of X-rays on carcinogens have been proven in recent years. Today, lead is used in many devices such as lead covers, thyroid protectors to protect the body against x-rays. But this equipment contains many disadvantages such as, Toxicity, High weight and Lack of flexibility. Today, newer methods, such as semi-solid skin care products (cream, ointment), are used. In this study, the feasibility of using a cream containing bismuth oxide nanoparticles as an X-ray absorbent was studied.
 
Materials and Methods: Bismuth oxide nanoparticles structure (Bi2O3) and formulation in ointment form was surveyed. Then were formulated by a new method using sorbitol synthesis. The final cream consists of 70% bismuth oxide nanoparticles and 30% other ingredients. Then the absorption of x-rays in different thicknesses of ointment was evaluated.
Results: A dosimetry test showed that the protective effect of ointment was significantly (P<0.05) better than the lead Sheet as control group. Dosimetry tests showed that the ointment of bismuth oxide nanoparticles absorbed 56% of the radiation, but the lead just absorbed 41%. Bismuth K absorption edge is more than other metals and its nanoparticles have higher absorption surface to volume (S/V).
Conclusion: Bismuth oxide nanoparticles, due to the high atomic number of bismuth, is more efficient than lead in X-ray absorption, and is less toxic. Bismuth oxide nanoparticles cream can be used as X-ray absorbent for various occupations such as doctors, dentists, operating room staff and radiologists, and increases the health and safety of the staff.