developmental effects. One byproduct of ethoxylation is 1,4-dioxane, a possible human carcinogen. Undiluted AEs can cause dermal or eye irritation. In aqueous solution, the level of irritation is dependent on the concentration. AEs are considered to have low to moderate toxicity for acute oral exposure, low acute dermal toxicity, and have mild irritation potential for skin and eyes at concentrations found in consumer products. Aquatic and environmental aspects AEs are usually released down the drain, where they may be adsorbed into solids and biodegrade through anaerobic processes, with ~28–58% degraded in the sewer. The remaining AEs are treated at waste water treatment plants and biodegraded via aerobic processes with less than 0.8% of AEs released in effluent. If released into surface waters, sediment or soil, AEs will degrade through aerobic and anaerobic processes or be taken up by plants and animals. Toxicity to certain invertebrates has a range of EC50 values for linear AE from 0.1 mg/L to greater than 100 mg/L. For branched alcohol exthoxylates, toxicity ranges from 0.5 mg/L to 50 mg/L. The EC50 toxicity for algae from linear and branched AEs was 0.05 mg/L to 50 mg/L. Acute toxicity to fish ranges from LC50 values for linear AE of 0.4 mg/L to 100 mg/L, and branched is 0.25 mg/L to 40 mg/L. For invertebrates, algae and fish the essentially linear and branched AEs are considered to not have greater toxicity than Linear AE. Alcohol ethoxysulfates (AESs) Biodegradation The degradation of AES proceeds by ω- or β-oxidation of the alkyl chain, enzymatic hydrolysis of the sulfate ester, and by cleavage of an ether bond in the AES producing alcohol or alcohol ethoxylate and an ethylene glycol sulfate. Studies of aerobic processes also found AES to be readily biodegradable. The half-life of both AE and AES in surface water is estimated to be less than 12 hours. The removal of AES due to degradation via anaerobic processes is estimated to be between 75 and 87%. In water Flow-through laboratory tests in a terminal pool of AES with mollusks found the NOEC of a snail, Goniobasis and the Asian clam, Corbicula to be greater than 730 ug/L. Corbicula growth was measured to be affected at a concentration of 75 ug/L. The mayfly, genus Tricorythodes has a normalized density NOEC value of 190 ug/L. Human safety AES has not been found to be genotoxic, mutagenic, or carcinogenic. A 2022 study revealed