§178.3120 Animal glue.
Animal glue may be safely used as a component of articles intended for use in producing, manufacturing, packing, processing, preparing, treating, packaging, transporting, or holding food, subject to the provisions of this section.
（a） Animal glue consists of the proteinaceous extractives obtained from hides, bones, and other collagen-rich substances of animal origin （excluding diseased or rotted animals）, to which may be added other optional adjuvant substances required in its production or added to impart desired properties.
（b） The quantity of any substance employed in the production of animal glue does not exceed the amount reasonably required to accomplish the intended physical or technical effect nor any limitation further provided.
（c） Any substance employed in the production of animal glue and which is the subject of a regulation in parts 174, 175, 176, 177, 178 and § 179.45 of this chapter conforms with any specification in such regulation.
（d） Optional adjuvant substances employed in the production of animal glue include:
（1） Substances generally recognized as safe in food.
（2） Substances subject to prior sanction or approval for use in animal glue and used in accordance with such sanction or approval.
（3） Substances identified in this paragraph （d）（3） and subject to such limitations as are provided:
| List of substances | Limitations |
| Alum (double sulfate of aluminum and ammonium, potassium, or sodium) | |
| 4-Chloro-3-methylphenol(p-chlorome-tacresol) | For use as preservative only. |
| Chromium potassium sulfate (chrome alum) | For use only in glue used as a colloidal flocculant added to the pulp suspension prior to the sheet-forming operation in the manufacture of paper and paper board. |
| 3,5-Dimethyl-1,3,5,H-tetrahydrothiadia-zine-2-thione | For use as preservative only. |
| Disodium cyanodithioimidocarbonate | Do. |
| Defoaming agents | As provided in § 176.210 of this chapter. |
| Ethanolamine | |
| Ethylenediamine | |
| Formaldehyde | For use as a preservative only. |
| Potassium N-methyldithiocarbamate | Do. |
| Potassium pentachlorophenate | Do. |
| Rosins and rosin derivatives | As provided in § 178.3870 . |
| Sodium chlorate | |
| Sodium dodecylbenzenesulfonate | |
| Sodium 2-mercaptobenzothiazole | For use as preservative only. |
| Sodium pentachlorophenate | Do. |
| Sodium o-phenylphenate | Do. |
| Zinc dimethyldithiocarbamate | Do. |
| Zinc 2-mercaptobenzothiazole | Do. |
（e） The conditions of use are as follows:
（1） The use of animal glue in any substance or article that is the subject of a regulation in this subpart conforms with any specifications or limitations prescribed by such regulation for the finished form of the substance or article.
（2） It is used as an adhesive or component of an adhesive in accordance with the provisions of § 175.105 of this chapter.
（3） It is used as a colloidal flocculant added to the pulp suspension prior to the sheet-forming operation in the manufacture of paper and paperboard.
（4） It is used as a protective colloid in resinous and polymeric emulsion coatings.