Hydrogen chloride

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

Hydrochloric acid is irritant or corrosive, depending on concentration, and its toxicity is related to site-of-contact effects. In contact with water it dissociates completely to give eventually hydronium and chloride ions, both normal constituents in the body of all mammalian species and under strict homeostatic control. No systemic toxicity is expected, including effects on reproduction.

Although no guideline-compliant reproduction toxicity study was identified, other useful data are available, and the level of concern is inadequate to justify further testing.

Effect on fertility: via oral route

Endpoint conclusion:

no study available

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

Hydrochloric acid is irritant or corrosive, depending on concentration, and its toxicity is related to site-of-contact effects. In contact with water it dissociates completely to give eventually hydronium and chloride ions, both normal constituents in the body of all mammalian species and under strict homeostatic control. No systemic toxicity is expected, including effects on reproduction.

In a fully compliant 90-d whole-body inhalation toxicity study carried out in two strains of rats and one strain of mice (Dudek B. R., 1984), decreased body weight associated to a decrease in food consumption was noted at the highest concentration (ca. 47 ppm, equivalent to approx. 37.5 mg/m3) in mice only. The animals experienced severe clinical signs again related to the corrosiveness of hydrogen chloride but notwithstanding the severe health status impairment, no abnormality at haematology or clinical chemistry was detected. Histopathological examination at terminal sacrifice failed to show any abnormality in major organs and tissues, including reproductive organs, and only changes in site-of-contact tissues/organs (lips and/or anterior portion of nasal airflow passage) were detected both in the two strains of rats and in mice.

In an inhalation carcinogenicity study in rats (Sellakumar A.R., et al., 1985) in which animals were exposed to 10 ppm HCl for 6 hours/day, 5 days/week up to 128 weeks histopathology revealed changes only at the site-of contact (i.e. increased incidence of hyperplasia of the larynx and trachea) but no abnormality was detected in major organs including reproductive ones. Moreover, no increase in any kind of tumours, compared to control animals was found.

Since hydrogen chloride dissociates entirely in aqueous media, the foetus will be exposed only to hydrogen and chloride ions (both of which are physiological electrolytes). While it is possible that an excess of hydrogen ions might alter pH sufficiently to affect the foetus, the results of Pavlova (1976) suggest such findings are in practice inseparable from maternal toxicity.

As a High Production Volume (HPV) chemical, hydrochloric acid has been subjected to the evaluation for identifying those materials for which further action (hazard identification or risk management measures) is considered necessary. The SIDS Initial Assessment Report (SIAR) developed under this programme for hydrogen chloride was discussed at SIAM No. 15 held in Boston 22 to 25 October 2002 at which it was agreed that, based on data presented, the chemical was of low priority for further work (OECD, 2002).

Based the local nature of the toxic effects of hydrogen chloride and on animal welfare grounds, a reproduction toxicity study is not considered necessary.

Effects on developmental toxicity

Description of key information

 Hydrochloric acid is irritant or corrosive, depending on concentration, and its toxicity is related to site-of-contact effects. In contact with water it dissociates completely to give eventually hydronium and chloride ions. The absorption, distribution, metabolism and excretion of acids and chloride are well known from human and mammalian physiology. The foetus will be exposed only to hydrogen and chloride ions, both of which are physiological electrolytes that are maternally regulated within a narrow range to maintain homeostasis. Although no guideline-compliant developmental toxicity study was identified, other useful data are available, and the level of concern is inadequate to justify further testing.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

Hydrochloric acid is irritant or corrosive, depending on concentration, and its toxicity is related to site-of-contact effects. In contact with water it dissociates completely to give eventually hydronium and chloride ions. The absorption, distribution, metabolism and excretion of acids and chloride are well known from human and mammalian physiology. The foetus will be exposed only to hydrogen and chloride ions, both of which are physiological electrolytes that are maternally regulated within a narrow range to maintain homeostasis.

Justification for classification or non-classification

No classification is required.

Although no guideline-compliant reproduction toxicity study was identified, other useful data are available, and the level of concern is inadequate to require further testing. The available data give no indication that HCl is toxic for reproduction. In contact with water it dissociates completely to give eventually hydronium and chloride ions which being physiologically abundantly present in organisms, are unlikely to lead to a hazard towards reproduction or development.