Benzene from Citric Acid and Sodium Benzoate?

DavidDavid Member
edited December 2014 in Formulating

Comments

  • MarkBroussardMarkBroussard Member, Professional Chemist
    It all depends on how much Citric Acid and how much Sodium Benzoate you are using in your formulation?  I've seen products on the shelf that do include Sodium Benzoate and Ascorbic Acid from well-known companies.
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    Provides Formulation Development and Lab-Scale Contract Manufacturing Services.  See website for details www.desertinbloomcosmeticslab.com

  • Sodium benzoate is well regulated, in beverages max 300 mg max if Im not mistaken, now citric can be incorporated in larger quantities in food and beverages, now I think that the trigger here is the pH which usually is very low (2.8-4.5).
  • Citric acid in combination with Sodium Benzoate will not lead to the formation of Benzene but you should be careful using Ascorbic acid and Citric acid in the same formulation, because Citric acid could accelerate the formation of Benzene. Even using Ascorbic acid and Sodium Benzoate in your formulation will not necessarily produce Benzene you will need additional conditions leading to the formation of Benzene.
  • I don't see the point of using sodium benzoate when potassium sorbate will get the job done safely and efficiently.
    Cosmetic Brand Creation. Concept to name to IMPI search to logo and brand registration. In-house graphic design inc. Pantone specs. Cosmetic label and box design & graphics.
  • @Belassi I don't know how often people use sodium benzoate to preserve their products. The problem is that many ingredients, especially botanical extracts, come preserved with Potassium Sorbate/Sodium Benzoate.
  • Bill_TogeBill_Toge Member, Professional Chemist
    edited December 2014
    the key phrase in that paper is "metal catalyzed" - the reaction won't happen unless there's iron present

    if you use deionised water (which, as far as I know, many food manufacturers don't), the concentration of iron and other metals is virtually nil, as is the probability of this reaction occurring
    UK based formulation chemist. Strongest subjects: hair styling, hair bleaches, hair dyes (oxidative and non-oxidative) I know some stuff about: EU regulations, emulsions (O/W and W/O), toothpaste, mouthwash, shampoos, other toiletries
  • MarkBroussardMarkBroussard Member, Professional Chemist
    After re-reading the article, I really don't think you have anything to worry about, particularly if you add a chelating agent to your formulation as the author noted that the addition of EDTA inhibited the reaction.  And, as Bill_Toge points out, the reaction is "metal catalysed" by either iron or copper.  So, add a chelating agent and the potential issue is pretty much resolved. 
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    Provides Formulation Development and Lab-Scale Contract Manufacturing Services.  See website for details www.desertinbloomcosmeticslab.com

  • Yes, MarkBroussard&Bill_Toge, you are right, there is nothing to worry about, I will just use a chelating agent. The reaction can't take place without a metal catalyst that can produce a hydroxyl radical.
  • @david its just a report and it isnt in paper form, is it authentic?
    @bill_toge here iron is catalyst and isnt necessary in formation of benzene
  • Bill_TogeBill_Toge Member, Professional Chemist
    @nasrins, it would take a very powerful reducing agent to reduce benzoic acid to benzene without assistance from a catalyst; ascorbic acid on its own is simply not that powerful
    UK based formulation chemist. Strongest subjects: hair styling, hair bleaches, hair dyes (oxidative and non-oxidative) I know some stuff about: EU regulations, emulsions (O/W and W/O), toothpaste, mouthwash, shampoos, other toiletries
  • ;nasrins what do mean with "just a report"?  it is a peer-reviewed scientific article. This is usually viewed as the most authentic source of science.
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