The use of HPMC in animal nutrition is of no concern for consumer safety.
The majority of the available studies have been performed in rats, just few of them in rabbits and dogs. Among those meeting the current criteria for toxicological testing, the no observed adverse effect level (NOAEL) values for the different modified celluloses were identified most often corresponding to the highest tested level or changes in body or organ weights. For microcrystalline cellulose (E 460) the identified NOAELs in rats ranged from 3,769 mg/kg body weight (bw) per day to 9,000 mg/kg bw per day and in all cases corresponded to the highest levels of the test substance. For methyl cellulose (E 461), the dose level of 3% in rats (equivalent to 2,700 mg/kw bw per day) was selected as the NOAEL based on a decrease in body and organ weight displayed in male rats administered with the top additive level (10%, equivalent to 9,000 mg/kg bw per day and day).
Hair care products:
hpmc for putty powder. Generally, a lower percentage is sufficient for basic applications, while higher percentages may be needed for more demanding tasks that require superior adhesion and durability. The precise ratio needs to be determined through careful experimentation and testing, balancing the desired properties with cost-effectiveness.