Return to FAN's Pesticide Homepage

Return to Unaccounted Sources of Fluoride Exposure

From Consol Glass - online as of July 27, 2004, at http://www.consol.co.za/html/fact_sheet.aspx

Prevention of bloom in glass packaging

Did you know…

• Soda-lime glass is one of the most inert (safe) materials used world-wide for packaging a number of food products.

• Prolonged storage of glass under humid conditions (such as those experienced in the Western Cape) can cause sodium carbonate to form on the surface of empty containers. This causes the glass surface to look milky. This process is called bloom.

• To prevent this bloom process taking place, the inside surface of a glass container can be made more chemically inert – by as much as ten times – by using a fluorine (F) gas treatment process, which was first applied in the patented Ball IT (Internal Treatment) process.

The process is based on creating contact between the still hot glass and a tiny quantity of hydrofluoric acid gas. This neutralises the sodium on the surface and prevents it coming away from the structure of the bottle once it has cooled down.

• The Ball IT Process – and subsequent improvements of it, which includes the use of Freon gasses 134a and 152a – leaves no extractable residue on the glass surface. In fact the F-treatment of glass has received FDA (Federal Food and Drug Administration in the USA) approval as not being a food additive. The process has been approved for the treatment of glass containers typically used for food, wine and liquor, as well as pharmaceuticals.

Glass producers world-wide are applying the F-treatment of the internal surface of glass containers to protect them against the possible risk of bloom formation during storage.

• 152a and 134a are both non toxic and environmentally friendly, i.e. they do not contribute to ozone depletion.

• Consol Glass uses only the highest standards and process for the application of Freon gas in the treatment of the internal surfaces of the glass containers we produce and distribute to prevent the occurrence of bloom, meeting the industry demand for this protection.

• Consol currently applies 152a to specific glass containers used in the liquor, spirit, beer and wine markets and applies stringent quality control in its application processes.

• Extensive studies have shown that both 152a and 134a Freon gas variants have extremely low levels of toxicity. This is further shown by the fact that 134a is marketed as a propellant for metered dose inhalers for asthma patients.

• Interestingly, the maximum acceptable level of fluoride in wines imported into the European Union has been set at 3 parts per million - ppm (as NaF). Tests done on Consol glass containers showed fluoride levels to be below 0.5 ppm. Ordinary tap water in South Africa contains 1 ppm.

Consol Glass - online as of July 27, 2004, at http://www.consol.co.za/html/beverages.aspx


In recent years, the re-emergence of the glass pack as a Brand differentiator in the South African food sector has lead to steady growth for glass sales in an aggressive and innovative domestic food category. Consol produces various glass products for the food industry with major product lines for baby food, mayonnaise, coffee, various sauces, fresh salads, anchovette, various spices, olive oils, chutney and various spreads including jams, honey etc.


Consol's participation in the South African beverage industry is focussed around domestic beer, wine and spirit sales and very recently large growth in export wine and domestic Flavoured Alcoholic Beverages. Non alcoholic beverages in glass have in recent years seen an increasing trend toward pack differentiation with Consol producing products for the carbonated soft drinks, fruit juice and the mineral water industries.