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When and why did the US ban borax and boric acid as food preservatives?

Research question: When and on what toxicological grounds were borax and boric acid removed from permitted food preservatives in the United States, and which early 20th-century feeding studies were cited in that decision?

The verified facts do not record when or by what formal decision borax and boric acid were removed from permitted food preservatives, so that part of the question cannot be answered from them. The toxicological grounds the facts do record come from the 1904 and 1905 borax experiment, which concluded that one-half gram per day of boric acid or borax is too much for a normal man to receive regularly ⁴⁷, and that both chemicals, given continuously in small doses or in large quantities over a short time, disturb appetite, digestion, and health ⁹. The authors also recommended restricting them to cases where their necessity is clearly manifest and labeling foods that contain them ¹¹. The feeding studies named in the record include Bureau of Chemistry Circular 15, Results of Borax Experiment, and Part I of Bulletin 84, which covered boric acid and borax ², as well as Dr. Wiley's boarding house experiments, in which twelve government clerks were fed boracic acid and developed nausea, headaches, and vomiting ⁵⁸. The newest fact is from 1906, roughly 120 years before October 2026 ³¹⁰.

Checked 2026-10-14. Only documented and supported facts are used.

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Sources

[1] documented

The U.S. Department of Agriculture's Bulletin 84, titled Influence of Food Preservatives and Artificial Colors on Digestion and Health, is one of the feeding studies on food preservatives referenced in this document.

"Bulletin 84, Influence of Food Preservatives and Artificial Colors on Digestion and Health, from the regular edition."

General results of the investigations showing the effect of salicylic acid and salicylates upon digestion and health (1906)

[2] supported

The Bureau of Chemistry's Circular 15, Results of Borax Experiment, is cited as a source of the borax feeding experiments, and Part I of Bulletin 84 covered boric acid and borax.

"as with Part I, Boric Acid and Borax, to publish the general results in the form of a circular for more general distribution."

General results of the investigations showing the effect of salicylic acid and salicylates upon digestion and health (1906)

[3] documented

In the early experiments at Dr. Wiley's boarding house, the research focused first on borax and boracic acid.

"During the first year the experiments were largely devoted to borax and boracic acid."

Image 25 of Evening star (Washington, D.C.), July 28, 1906

[4] documented

In the 1904 experiments, a daily intake of one-half gram of boric acid (or borax expressed as boric acid) was judged too much for a normal man to receive regularly.

"On the whole the results show that one-half gram per day is too much for the normal man to receive regularly."

Results of borax experiment (1904)

[5] supported

Dr. Wiley fed twelve government clerks food containing boracic acid, starting with about half a pea-sized amount per day and gradually increasing it.

"He took these twelve lusty clerks and fed them food which contained Just so much boracic acid."

Image 25 of Evening star (Washington, D.C.), July 28, 1906

[6] documented

The same study concluded that a normal man could take one-half gram per day of boric acid, or borax expressed as boric acid, for a limited time without much danger to health.

"On the other hand it is evident that the normal man can receive one-half gram per day of boric acid, or of borax expressed in terms of boric acid, for a limited period of time without much danger of impairment of health."

Results of borax experiment (1904)

[7] documented

The experiment's conclusion was that one-half gram of boric acid or borax (as boric acid) per day is too much for a normal man to receive regularly.

"On the whole the results show that one-half gram per day is too much for the normal man to receive regularly."

Results of borax experiment (1905)

[8] documented

The boarders developed nausea, headaches, and vomiting, and the investigators concluded that borax was the cause.

"there was no doubt but that the borax was the cause or the trouble"

Image 25 of Evening star (Washington, D.C.), July 28, 1906

[9] documented

The experiment found that both boric acid and borax, given continuously in small doses over a long period or in large quantities over a short period, cause disturbances of appetite, digestion, and health.

"It appears, therefore, that both boric acid and borax, when continuous administered in small doses for a long period, or when given in large quantities for a short period, create disturbances of appetite, of digestion and of health."

Results of borax experiment (1905)

[10] supported

When the findings were first published, meat packers argued that borax and boracic acid were harmless, and Wiley's published report, which gave the full story of the experiments, caused a major outcry from the packers.

"When these facts were first published the packers claimed that borax and boracic acid were harmless"

Image 25 of Evening star (Washington, D.C.), July 28, 1906

[11] supported

The authors concluded that boric acid and borax should be restricted to cases where their necessity is clearly manifest and other preservation methods are not applicable, and that foods containing them should be labeled.

"the logical conclusion which seems to follow from the data at our disposal is that boric acid and equivalent amounts of borax in certain quantities should be restricted to those cases where the necessity therefor is clearly manifest"

Results of borax experiment (1905)