There is no evidence to suggest that carboxymethyl cellulose (CMC) is carcinogenic or cancer-causing in humans.
The International Agency for Research on Cancer (IARC), which is a specialized agency of the World Health Organization (WHO) that is responsible for evaluating the carcinogenicity of substances, has not classified CMC as a carcinogen. Similarly, the United States Environmental Protection Agency (EPA) and the European Food Safety Authority (EFSA) have not identified any evidence of carcinogenicity associated with CMC.
Several studies have investigated the potential carcinogenicity of CMC in animal models, and the results have been generally reassuring. For example, a study published in the Journal of Toxicologic Pathology found that dietary administration of CMC did not increase the incidence of tumors in rats. Similarly, a study published in the Journal of Toxicology and Environmental Health found that CMC was not carcinogenic in mice when administered at high doses.
Furthermore, CMC has been evaluated for safety by regulatory agencies around the world, including the US Food and Drug Administration (FDA), which has approved CMC for use in food, pharmaceuticals, and cosmetics. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) has also evaluated the safety of CMC and established an acceptable daily intake (ADI) of up to 25 mg/kg of body weight per day.
In summary, there is currently no evidence to suggest that carboxymethyl cellulose is carcinogenic or poses a cancer risk to humans. CMC has been extensively evaluated for safety by regulatory agencies around the world and is considered safe for use in the quantities allowed by these agencies. However, it is important to use CMC and other food additives in accordance with recommended guidelines and in moderation to minimize any potential risks.