Background of ChemFORWARD Screening: A ChemFORWARD chemical hazard assessment (CHA) is conducted following ChemFORWARD Assessor Guidance (v 2.0, dated August 11, 2023, and Amendment: Polymer Assessment, dated June, 2022), and comprises a comprehensive evaluation and hazard classification of 24 human health and environmental toxicity endpoints, based on criteria from the United Nations’ Globally Harmonized System of Classification and Labelling of Substances (GHS) and Cradle to Cradle Certified® Material Health Assessment Methodology, version 4 (C2CMHAM)(v.4.0) (C2CPII 2022a) and Cradle to Cradle Certified Exposure Assessment Methodology (C2CPII 2022b). As the evaluation includes assessment of oral, dermal, and inhalation routes of exposure, a ChemFORWARD CHA includes over 50 written rationales and data summaries to support conclusions and hazard classifications. Each ChemFORWARD hazard endpoint assessed using GHS receives a numerical GHS Category rating, with lower hazard categories indicating a higher hazard, or a classification of “NC” (not classified), indicating that available data do not support a hazard classification according to GHS criteria. ChemFORWARD also utilizes “E” (equivocal) when data are not discerning, and “CNP” (classification not possible) in instances where there are no data or insufficient data. As there are no GHS classification criteria for endocrine activity, the phrases “No data identified” or “Insufficient data” may apply. ChemFORWARD hazard endpoints assessed under Cradle to Cradle Certified® methodology (“C2C”) receive ratings of Green, Yellow, Red, or Grey to indicate a low, moderate, or high hazard, or insufficient data, respectively. It may be noted that the combination of endpoints assessed under Terrestrial Toxicity, Other (Human Health), and Other (Environmental Health) are derived from C2C Certified® methodology; therefore, a ChemFORWARD screen assesses these endpoints only with color codes. Background of Aluminum Chloride, Basic: Aluminum chloride, basic is glassy solid under standard temperature and pressure and functions as an odor agent, water treatment chemical, and active ingredient in deodorants and antiperspirants. Since it is an inorganic aluminum salt, it is not a VOC. Screening Results: Human Health, Environmental, Cradle to Cradle Certified® Hazards: Human health hazards associated with aluminum chloride, basic include mutagenicity, reproductive toxicity (oral), developmental toxicity (oral), endocrine activity, repeated exposure specific target organ toxicity (inhalation), repeated exposure neurotoxicity (oral), respiratory sensitization, skin irritation, and eye irritation. Related soluble aluminum salts, including aluminum chloride and aluminum sulfate, were used to fill some (but not all) data gaps. Remaining data gaps include reproductive toxicity (dermal, inhalation), developmental toxicity (dermal, inhalation), lactation toxicity, acute toxicity (inhalation), single exposure specific target organ toxicity (inhalation), repeated exposure specific target organ toxicity (dermal), single exposure neurotoxicity (inhalation), repeated exposure neurotoxicity (dermal, inhalation), and respiratory irritation. No reasonable surrogates with relevant data were identified to fill these data gaps.Environmental concerns include acute and/or chronic toxicity potential towards aquatic biota. As an inorganic salt at its most stable valence, aluminum chloride, basic is not rapidly degradable. Following Cradle to Cradle Certified® Products Program Material Health Assessment Methodology (C2CMHAM)(v. 4.0) (C2CPII 2022a), the overall C2C chemical hazard rating for aluminum chloride, basic is Red, based on the worst individual endpoint rating of Red for mutagenicity, reproductive and developmental toxicity, inhalation toxicity, respiratory sensitization, skin and eye irritation, other (human health) for corrosion of metals, and the combined aquatic toxicity risk flag. Following the exposure assessment component of a C2C Material Health Assessment as described in Section 2.2 (Process Steps) and Section 4 (Exposure Assessment and Assigning Risk Flags) of the C2CPII MHAM (C2CPII 2022a) and C2CPII’s Exposure Assessment Methodology (C2CPII 2022b), this hazard rating will be used to assign either a Yellow or Red risk flag based on likely use/manufacture scenarios of the product containing this chemical. The Red rating for other (human health) is intended to identify other potential hazards not covered by other endpoints. In a C2C Material Health assessment, a Red rating for other (human health) serves as a reminder to consider this additional hazard information in the risk assessment step conducted as part of a C2C Material Health assessment. Overall Hazard Assessment for Aluminum Chloride, Basic: Aluminum chloride, basic has a relatively robust health effects dataset for the oral route of exposure, with health hazards identified for reproductive toxicity, developmental toxicity and repeated exposure neurotoxicity. No hazards were identified for the dermal route, although data gaps exist for reproductive toxicity, developmental toxicity, repeated exposure specific target organ toxicity and repeated exposure neurotoxicity. The only health hazard classified for the inhalation route of exposure is repeated exposure specific target organ toxicity, although data gaps exist for reproductive toxicity, developmental toxicity, acute toxicity, single exposure specific target organ toxicity, and single and repeated exposure neurotoxicity. Aluminum chloride, basic is genotoxic, corrosive to the skin and eyes and is sensitizing to the respiratory tract, but is not a skin sensitizer. It also has an endocrine disruption potential. There are insufficient data to classify this chemical as a respiratory irritant, or assess whether this chemical is a lactation toxicant. In terms of environmental hazards, aluminum chloride, basic poses an acute hazard to fish, crustacea, and algae and a chronic hazard to algae. It is not rapidly degradable but may dissociate to its constituent ions and is not likely to bioaccumulate. It is not likely to pose a hazard to soil organisms.In terms of physical hazards, aluminum chloride, basic is not flammable, explosive, or oxidizing but is corrosive to metals. For purposes of performing a cosmetics ingredient safety assessment, a NOAEL of 26 mg/kg/day (converted from a NOAEL of 8.06 mg Al/kg/day) point of departure is recommended for aluminum chloride, basic, and is based on the NOAEL from a GLP-compliant two-generation reproduction toxicity test in rats exposed to the surrogate aluminum sulfate and a safety factor of 1. This study was selected as the key study in United States Environmental Protection Agency (U.S. EPA)’s risk assessment of aluminum sulfate (U.S. EPA 2015).New Alternative Methods (NAMs) used in this assessment comprise in vitro assays for genotoxicity, endocrine activity, and skin irritation. The quality, utility, and accuracy of NAM predictions are greatly influenced by two primary types of uncertainties (OECD 2020):• Type I: Uncertainties related to the input data used• Type II: Uncertainties related to extrapolations madeType I (input data) uncertainties in aluminum chloride, basic’s NAMs dataset include no or insufficient experimental data for respiratory sensitization and endocrine disruption, and lack of established test methods for respiratory sensitization. Aluminum chloride, basic’s Type II (extrapolation output) uncertainties include limitations of in vitro genotoxicity assays in mimicking in vivo metabolism and their focusing on one or only a few types of genotoxicity events, the inability of the in vitro endocrine activity testing to account for the in vivo bioavailability of the compound, and the OECD Guideline 435 test only being able to positively identify corrosive substances. Some of aluminum chloride, basic’s type II uncertainties were alleviated by the use of in vitro test batteries and/or in combination of in vivo data.