The content of this safety and health topic is limited to inorganic (mineral) acids and bases and does not include organic chemical compounds that function as acids and bases, such as acetic acid (the chief component in vinegar) and pyridine, respectively.
An acid is a chemical that (1) donates a hydrogen ion (H+), or (2) can form a covalent bond with an electron pair (a Lewis acid). Examples of commonly used acids are hydrochloric acid (HCl) and sulfuric acid (H2SO4).
A base is a chemical that (1) can accept a hydrogen ion, or (2) can donate an electron pair to form a covalent bond with a Lewis acid. Examples of bases include ammonia (NH3), sodium hydroxide (NaOH), potassium hydroxide (KOH), and calcium hydroxide (Ca(OH)2).
What are the hazards associated with acids and bases?
Physical hazards. Fires can occur when oxidizing acids such as nitric acid, HNO3, mix with flammable or combustible chemicals. Explosions can result when anhydrous perchloric acid (HClO4) is mixed with organic compounds resulting in the formation of shock sensitive organic perchlorates when dry.
Nitric acid is also used in reactions with toluene and glycerol separately, to produce 2,4,6-trinitrotoluene (TNT) and nitroglycerin (1,2,3-propane trinitrate), respectively. Both are used as explosives and nitroglycerin is also used in medicine as a vasodilator.
Health hazards associated with working with acids and bases are primarily due to their corrosivity, which results in destruction of tissue. Hydrofluoric acid, HF, has the insidious property of penetrating skin without causing any burning sensation and causing extensive destruction of underlying tissue.
What can I do to protect myself and others?
Employees using strong acids and bases must understand the hazards of each of the chemicals they use. Employers must provide employees with the necessary hazard information and appropriate personal protective equipment, especially eye and face protection and impervious gloves.
Work with perchloric acid must always be done in dedicated, specially-designed fume hoods that are equipped with wash down capability of the exhaust ductwork. This prevents the formation and accumulation of shock-sensitive perchlorates.
Persons exposed to hydrogen fluoride should seek prompt immediate medical attention. Failure to do so can result in death due to pulmonary edema or heart disorders.
What resources are available to assist employers?
Training and Outreach Services
The presentations on hazard communication and personal protective equipment are available to assist employers in training their staff. Each of these presentations should be modified to address site-specific conditions and hazards. These pre-recorded webinars on hazard communication, respiratory protection and toxic and hazardous substances can also be accessed at any time.
IIn addition, the education, training and technical assistance bureau provides free online safety and health training and outreach services (i.e., speaker's bureau requests, safety booths) upon request.
Lastly, the NCDOL Library offers free safety and health videos (including streaming video services) and related research assistance on consensus standards (i.e., ANSI, NFPA, NEC).
Safety and Health Programs
A-Z Safety and Health Topics
The consultative services bureau provides free and confidential onsite consultation regarding worksite safety and health hazards.
Which standards apply?
OSH has adopted the following standards which are applicable to acids and bases in North Carolina. Note: Please also check the standards information and activity webpage to see if there has been any recent or upcoming regulatory activity on this topic.
29 CFR 1910 Subpart G - occupational health and environmental control
29 CFR 1910.94 - ventilation
29 CFR 1910 Subpart I – personal protective equipment
29 CFR 1910 Subpart J - general environmental controls
29 CFR 1910.141 - sanitation
29 CFR 1910 Subpart K - medical and first aid
29 CFR 1910.151 - medical services and first aid
29 CFR 1910 Subpart Z - toxic and hazardous substances
Other Applicable Standards
The Which OSHA Standards Apply webpage can help identify other standards that may be applicable to your worksite.
Where can I learn more?
Industry Guide 49 - OSHA General Industry Standards Requiring Programs, Inspections, Procedures, Records and/or Training provides requirements for general industry standards.
If you would like to receive interpretive guidance on this or any other OSH standard or topic, you can submit your questions using the Ask OSH web form, by e-mail to email@example.com or by calling 919-707-7876.