E218 (Methyl p-hydroxybenzoate)  is a chemical compound belonging to the paraben family.

The name defines the structure of the molecule

• "Methyl" indicates the presence of a methyl group, which is an alkyl group with the formula CH3.
• "p-hydroxy" indicates the presence of a hydroxy group (OH) in the para position relative to the benzoate functional group on the benzene structure.
• "Benzoate" indicates the presence of a benzoate group, which is an ester of benzoic acid.

Description of raw materials used in production

• p-Hydroxybenzoic Acid - An aromatic compound that is the primary precursor of methylparaben.
• Methanol - Used as an alkylating agent to esterify the p-hydroxybenzoic acid.
• Catalyst - For example, sulfuric acid, which accelerates the esterification reaction.

Step-by-step summary of industrial chemical synthesis process.

• Mixing - The p-hydroxybenzoic acid and methanol are mixed together.
• Esterification - The mixture is heated in the presence of a catalyst to form the methyl ester of p-hydroxybenzoic acid.
• Cooling and Separation - The reacted mixture is cooled and the formed product separates.
• Purification - The crude product is purified through techniques such as distillation or crystallization.
• Drying - Moisture is removed from the product.
• Packaging - Methyl p-hydroxybenzoate is packaged in suitable containers for transport and sale.
• Quality Control - The final product undergoes various quality checks to ensure it meets specifications.

What it is used for and where

Food

Ingredient on the European food additives list as E218, preservative.

Preservative. Any product containing organic, inorganic compounds, water, needs to be preserved from microbial contamination. Preservatives act against the development of harmful microorganisms and against oxidation of the product.

Safety

Parabens are preservative chemical compounds that have been the subject of attention in the scientific literature as possible endocrine disruptors (particularly propylparaben and butylparaben), i.e. with the possibility of damaging the hormone-producing glands in our bodies, particularly in the breasts. The 2004 study by Darbre et al. showed that parabens remain in our bodies as intact esters (2). Following this study, some of the scientific literature in 2005 and 2006 cast doubt on Darbre's conclusions and claimed they were limited. However, both the US FDA and the European SCCP authorised in 2006 the use of a single paraben in cosmetic products at a concentration of 0.4% and the use of total parabens at a concentration of 0.8%. However, there is no shortage of studies that consider the restrictions unnecessary: M. G. Kirchhof et al. in 2013 found that parabens are among the safest and most well-tolerated preservatives and that current data do not support drastic regulations or personal exposure restrictions. Darbre in 2014 published a further study in which he showed how parabens can cause DNA damage.

• Molecular Formula    C₈H₈O₃
• Linear Formula    HOC₆H₄CO₂CH₃
• Molecular Weight  152.15
• CAS   99-76-3 
• UNII    A2I8C7HI9T
• EC Number   202-785-7
• DSSTox Substance ID  DTXSID4022529
• IUPAC  methyl 4-hydroxybenzoate
• InChl=1S/C8H8O3/c1-11-8(10)6-2-4-7(9)5-3-6/h2-5,9H,1H3
• InChl Key      LXCFILQKKLGQFO-UHFFFAOYSA-N
• SMILES   COC(=O)C1=CC=C(C=C1)O
• MDL number  MFCD00002352
• PubChem Substance ID    329815219
• ChEBI  31835
• RTECS  DH2450000
• Beilstein    509801
• FEMA    2710
• RXCUI    29903   
• NSC      406127    3827
• NACRES NA.25 

Synonyms :

• E218
• Sodium Methylparaben
• Methylparaben
• Solparol
• Metilparaidrossibenzoato

• Methyl-4-hydroxybenzoate
• p-Hydroxybenzoic acid methyl ester
• methyl para-hydroxybenzoate
• Metagin
• NIPAGIN
• p-Hydroxybenzoic acid, methyl ester
• p-Hydroxybenzoic methyl ester
• Methyl parasept
• Tegosept M
• 4-Hydroxybenzoic acid methylester
• 4-Hydroxybenzoic Acid Methyl Ester
• 4-(Methoxycarbonyl)phenol
• Methyl parahydroxybenzoate