Final Report on the Safety Assessment of Ammonium and Glyceryl Thioglycolates and Thioglycolic Acid

A review of hair removal modalities in pediatric patients: Ethical and clinical considerations

Unwanted hair is a common concern among patients presenting to pediatric dermatology clinics, and parents and patients alike inquire about the safety of methods employed for elective removal. Various methods of hair removal exist with different levels of invasiveness and permanence, from simple mechanical depilation to light-based therapies. All methods of hair removal appear to be safe and generally well tolerated in children, and there are no age restrictions to any modality. In this review, we aim to address the available literature on the safety and efficacy of hair removal modalities in pediatric patients and propose guidance on how to manage requests for at-home and in-office therapies within an ethical framework.

Measurement of concentrations of thioglycolic acid, dithiodiglycolic acid and ammonia in indoor air of a beauty salon

OBJECTIVES

Among the many chemicals used in a hair salon, exposure to thioglycolic acid (TGA) used for permanent waving solutions (PWS) potentially causes adverse health effects. However, no report has been previously published on the indoor air concentrations of TGA in a beauty salon that contributes to assessment of exposure to TGA of hairdressers and their customers. This study aimed to demonstrate the present concentration levels of TGA in indoor air of a beauty salon where the PWS containing ammonium thioglycolate was actually used for perm treatments.

METHODS

A field measurement of TGA, dithiodiglycolic acid (DTDGA, a reaction product of TGA and cysteine residues of hair keratin) and ammonia was carried out in a beauty salon located at Tokyo, Japan, from June 30 to July 2. Both TGA and DTDGA were collected in water using an impinger and determined by high performance liquid chromatography (HPLC).

RESULTS

The indoor air concentrations of TGA were below the limit of detection of 0.008 mg m(-3) at every event and much lower than occupational safety guideline levels set by the NIOSH and ACGIH. Meanwhile, the concentrations of ammonia ranged from 0.15 to 0.87 mg m(-3), and relatively higher concentrations were found during perm events and in samples collected near stations used for perm treatments. Concentrations of DTDGA varied from <0.026 mg m(-3) to 0.75 mg m(-3).

CONCLUSIONS

There was a different emission process of TGA and ammonia from PWS, and airborne TGA is not important as a possible exposure route for hairdressers and customers in this beauty salon.

Final Amended Report on the Safety Assessment of Ammonium Thioglycolate, Butyl Thioglycolate, Calcium Thioglycolate, Ethanolamine Thioglycolate, Ethyl Thioglycolate, Glyceryl Thioglycolate, Isooctyl Thioglycolate, Isopropyl Thioglycolate, Magnesium Thioglycolate, Methyl Thioglycolate, Potassium Thioglycolate, Sodium Thioglycolate, and Thioglycolic Acid

This safety assessment includes Ammonium and Glyceryl Thioglycolate and Thioglycolic Acid Butyl, Calcium, Ethanolamine, Ethyl, Isooctyl, Isopropyl, Magnesium, Methyl, Potassium, and Sodium Thioglycolate, as used in cosmetics. Thioglycolates penetrate skin and distribute to the kidneys, lungs, small intestine, and spleen; excretion is primarily in urine. Thioglycolates were slightly toxic in rat acute oral toxicity studies. Thioglycolates are minimal to severe ocular irritants. Thioglycolates can be skin irritants in animal and in vitro tests, and can be sensitizers. A no-observable-adverse-effect level for reproductive and developmental toxicity of 100 mg/kg per day was determined using rats. Thioglycolates were not mutagenic, and there was no evidence of carcinogenicity. Thioglycolates were skin irritants in some clinical tests. Clinically significant adverse reactions to these ingredients used in depilatories are not commonly seen, suggesting current products are formulated to be practically nonirritating under conditions of recommended use. Formulators should take steps necessary to assure that current practices are followed.

Developmental toxicity evaluation of sodium thioglycolate administered topically to Sprague-Dawley (CD) rats and New Zealand White rabbits

BACKGROUND

Sodium thioglycolate, which has widespread occupational and consumer exposure to women from cosmetics and hair-care products, was evaluated for developmental toxicity by topical exposure during the embryonic and fetal periods of pregnancy

METHODS

Timed-mated Sprague-Dawley rats (25/group) and New Zealand White (NZW) rabbits (24/group) were exposed to sodium thioglycolate in vehicle (95% ethanol:distilled water, 1:1) by unoccluded topical application on gestational days (GD) 6-19 (rats) or 6-29 (rabbits) for 6 hr/day, at 0, 50, 100, or 200 mg/kg body weight/day (rats) and 0, 10, 15, 25, or 65 mg/kg/day (rabbits). At termination (GD 20 rats; GD 30 rabbits), fetuses were examined for external, visceral, and skeletal malformations and variations.

RESULTS

In rats, maternal topical exposure to sodium thioglycolate, at 200 mg/kg/day (the highest dose tested) on GD 6-19, resulted in maternal toxicity, including reduced body weights and weight gain, increased relative water consumption and one death. Treatment-related increases in feed consumption and changes at the applicationsite occurred at all doses, in the absence of increased body weights or body weight change. Fetal body weights/litter were decreased at 200 mg/kg/day, with no other embryo/fetal toxicity and no treatment-related teratogenicity in any group. In rabbits, maternal topical exposure to sodium thioglycolate on GD 6-29 resulted in maternal dose-related toxicity at the dosing site in all groups; no maternal systemic toxicity, embryo/fetal toxicity, or treatment-related teratogenicity were observed in any group.

CONCLUSIONS

A no observed adverse effect level (NOAEL) was not identified for maternal toxicity in either species with the dosages tested. The developmental toxicity NOAEL was 100 mg/kg/day (rats) and > or = 65 mg/kg/day (rabbits; the highest dose tested). The clinical relevance of theses study results is uncertain because no data were available for levels, frequency, or duration of exposures in female workers or end users.