Inorganic particle content of foods and drugs

Our plain-English summary of Inorganic particle content of foods and drugs, by W.V. Eisenberg (Environmental Health Perspectives, 1974).

The study

• Author: W.V. Eisenberg
• Journal: Environmental Health Perspectives
• Published: 1974;9:183-91
• Cited by: 7 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Inorganic particulate matter in foods and drugs is discussed from the standpoint of determination by optical microscopy, source, and regulatory significance. Some particulate matter may be generated as extraneous material and traced to specific operational practices during processing and production with excessive levels associated with deficiencies in good manufacturing practices. Other particles, such as talc and asbestos, may be incorporated as additives during their use in production. Data on particles in parenteral drugs are discussed generally. Specific data on glass particles in foods and sand and soil particles in spices are presented.

In plain English

This 1974 paper by an author at the U.S. Food and Drug Administration (FDA) was an overview, not a single study. It discussed examples of inorganic particles in foods and drugs, mainly as measured by light microscopy. On asbestos, the author wrote that talc was a significant potential route for asbestos fibers to enter foods and drugs. Preliminary analysis of relatively few commercial talc samples used in foods and cosmetics found tremolite as the only asbestos type in the samples that contained asbestos. The paper pictured chrysotile fibers from a filter pad used to filter vinegar. It also described an FDA proposal to reduce asbestos fibers in injectable drugs, citing the hazard shown in animals injected with asbestos. Other data covered glass. At eight glass plants, 2,300 jars sampled at the annealing oven held 268 glass particles, and a separate 2,300 jars sampled at warehouses held 401. Glass turned up at all 31 food plants surveyed in 1958 and in every food type tested, in 3.3% to 36% of jars. The author noted that light microscopy cannot resolve the smallest fibers, and concluded that combining analytical methods would give a better evaluation.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Narrative overview of particle contamination problems in foods and drugs from a U.S. FDA regulatory standpoint, presenting survey data as examples
• Who was studied: Foods, drugs and glass containers examined in the U.S.: glass jars from eight glass plants, sampled at the annealing oven (2,300 jars) and at warehouses (2,300 jars). Also glass-packaged foods from 31 food plants (1958), ground spices, peanut butter samples (industry survey), and a few commercial talc samples used in foods and cosmetics
• Exposure: Inorganic particles in foods and drugs: glass, sand and soil, and asbestos fibers (chrysotile, tremolite) entering through talc or asbestos-containing filters
• Main results:
  • In the few commercial talc samples analyzed (talc used in foods and cosmetics), tremolite was the only asbestos type found in the samples that contained asbestos; the author called these data preliminary
  • Microscopic counts in talc spiked with known amounts of asbestos: chrysotile at 0.1% gave 112 per mg and at 1.0% gave 141 per mg; tremolite at 0.1% gave 125 per mg
  • The article showed chrysotile and cotton fibers from a filter pad used to filter vinegar
  • The article described an FDA proposal, based on hazard shown in animals from injection of asbestos fibers, to reduce asbestos fiber content in injectable (parenteral) drugs to the minimum feasible level
  • At eight glass plants, 2,300 jars sampled at the annealing oven discharge contained 268 glass particles (Table 1). A separate sample of 2,300 jars taken in cartons at the glass manufacturers' warehouses contained 401 particles (Table 2)
  • Particles per container were higher at the warehouse than at the annealing oven for all container sizes. The largest increase, 113%, was for medium (baby food) containers, and the average increase for all containers was 49.8%
  • Of the glass particles found in the glass manufacturing plants, 93-96% were 0.1-0.4 mm in size
  • In glass-packaged foods from 31 food plants (1958), glass particles were found at every plant and in every type of food tested. Jars with glass ranged from 3.3% (mustard, 2 of 60) to 36% (peanut butter, 128 of 356) in Table 3. Containers not cleaned before use were cited as a possible source in 65% of plants
  • Sand and soil (water-insoluble inorganic residue) in spices was generally highest in leafy herb spices; the limit for peanut butter was 35 mg per 100 g
• The authors' conclusion: The author concluded that a combination of analytical techniques and data would evaluate these particle problems better than any single method considered in isolation
• Limitations the authors state:
  • Light microscopy cannot resolve the smallest asbestos fibers, which matters where fiber size is critical
  • The talc findings were preliminary and based on relatively few commercial samples

Topics

Medical terms in this study, explained in our Lexicon: Talc.

Related studies

• Asbestos contamination of parenteral drugs — W.J. Nicholson, C.J. Maggiore, et al. (1972)
• Morphologic characterization of alveolar macrophages from subjects with occupational exposure to inorganic particles — T. Takemura, W.N. Rom, et al. (1989)
• Inorganic particles of agricultural origin — K. Kay (1974)
• Oxidative and cytotoxic stress induced by inorganic granular and fibrous particles — S. Helmig, D. Walter, et al. (2018)
• Evaluation by electron microscopy techniques of asbestos contamination in industrial, cosmetic, and pharmaceutical talcs — L. Paoletti, S. Caiazza, et al. (1984)
• High-resolution imaging of organic pharmaceutical crystals by transmission electron microscopy and scanning moiré fringes — M. S'ari, N. Koniuch, et al. (2020)

Browse more research in Environmental Health Perspectives, or return to medical research.