Hydrochloric Acid

2020-09-18

Hydrochloric acid, aka HCI or hydrochloride, is a slightly yellow to colourless, corrosive acid with a strong odour. It is non-combustible and non-flammable, with a pH of <1. The acid belongs to a class of inorganic compounds known as halogen hydrides. [1,2,3]

Uses [1,4]

Hydrochloric acid is used across a range of applications in various industries. It is commonly used in industrial processes, such as in the production of batteries and fireworks. It is also used to adjust pH levels in pools, and as a way to pickle steel, including rust and scale removal. Hydrochloric acid is used in the production of drinking water, other beverages, foods, and pharmaceuticals. It is also used in the tanning industry.

Routes of Exposure [5]

The main route of exposure to hydrochloric acid are ingestion or skin or eye contact.

Health Effects

Hydrochloric acid poisoning affects a range of systems, including the integumentary and respiratory systems.

Acute Effects [2]

Severity of symptoms depend on the level and type of exposure.

Acute exposure from inhalation to the acid can result in hoarseness, coughing, chest pain, ulceration and inflammation of the respiratory tract and pulmonary oedema. These symptoms are exacerbated for people who suffer from asthma. Acute oral exposure can also cause nausea, vomiting, diarrhea, and corrosion of the mucous membranes, stomach and oesophagus. Dermal contact to hydrochloric acid can result in scarring, ulceration and severe burns.

Chronic Effects [1,5]

Chronic exposure to hydrochloric acid is toxic to multiple body systems. Long term exposure to the chemical compound can cause dermatitis, photosensitisation, chronic bronchitis and gastritis. Prolonged exposure to low concentrations of the acid may result in dental erosion and discolouration.

Safety

~h2First Aid Measures [4]

  • Ingestion: If swallowed, contact a medical professional immediately. If medical attention is not available immediately, the patient is more than 15 minutes from the hospital, or unless instructed otherwise, induce vomiting ONLY IF THE PATIENT IS CONSCIOUS.
  • Skin contact: Remove all contaminated clothing, footwear and accessories. Do not re-wear clothing until it has been thoroughly decontaminated. Immediately rinse affected areas with plenty of soap and water. If irritation persist, contact a doctor immediately.
  • Eye contact: Flush eyes (including under the eyelids), with water for at least 15 minutes. Removal of contact lenses should only be done by skilled personnel. Contact a medical professional immediately.
  • Inhalation: Take victim away from the contaminated area to the nearest fresh air source and monitor their breathing. Keep the victim warm. If the victim is not breathing, and you are qualified, you may perform CPR with a one-way valve or protective mask. Immediately contact a medical professional. 
  • General: Never administer anything by mouth to an unconscious, exposed person.

  • Exposure Controls/Personal Protection [4]

  • Engineering controls: Emergency eyewash fountains and quick-drench areas should be accessible in the immediate area of the potential exposure. Ensure there is adequate ventilation. Use a local exhaust ventilation or process enclosure, to limit the amount of acid in the air.

  • Personal protection: Safety glasses, protective and dustproof clothing, gloves, an apron and an appropriate mask or dusk respirator. Wear impervious shoes. Do not wear contact lenses. For specifications regarding other PPE, Follow the guidelines set in your jurisdiction.

Regulation [6]

~h2United States:

The Occupational Safety and Health Administration (OSHA) has set a permissible exposure limit (PEL) concentration limit for hydrochloric acid of 5ppm.

Australia [7]

An 8-hour time-weighted average (TWA) for hydrochloric acid of 5ppm has been set.

References

https://www.sydneysolvents.com.au/hydrochloric-acid

https://www.sciencedirect.com/topics/earth-and-planetary-sciences/hydrochloric-acid

https://pubchem.ncbi.nlm.nih.gov/compound/Hydrochloric-acid

https://jr.chemwatch.net/chemwatch.web/account/login

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/337689/hpa_hydrogen_chloride_toxicological_overview_v1.pdf

https://www.cdc.gov/niosh/npg/npgd0332.html

https://www.chemsupply.com.au/documents/HL0201CH34.pdf