Bis (2-propylheptyl) phthalate

Structural formula
Simplified structural formula of the main structural isomer without stereochemistry
General
Surname	Bis (2-propylheptyl) phthalate
other names	Bis (2-propylheptyl) phthalate Di-2-propylheptyl phthalate Dipropyl heptyl phthalate DPHP
Molecular formula	C 28 H 46 O 4
Brief description	colorless liquid
External identifiers / databases
CAS number 53306-54-0 EC number 258-469-4 ECHA InfoCard 100.053.137 PubChem 92344 Wikidata Q25099943
properties
Molar mass	446.67 g mol −1
Physical state	liquid
density	0.960-0.965 g cm -3
Melting point	−48 ° C
boiling point	251–253 ° C (7 hPa)
Vapor pressure	3.7 · 10 –8 hPa (20 ° C)
solubility	practically insoluble in water (<0.1 µg · l −1 at 25 ° C)
safety instructions
GHS labeling of hazardous substances no GHS pictograms H and P phrases H: no H-phrases P: no P-phrases
Toxicological data	> 5000 mg kg −1 ( LD 50 ,  rat ,  oral ) > 2000 mg kg −1 ( LD 50 ,  rabbit ,  transdermal )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Bis (2-propylheptyl) phthalate ( DPHP ) is a mixture of several isomeric chemical compounds from the group of phthalic acid esters .

Extraction and presentation

Bis (2-propylheptyl) phthalate, by the dimerization of valeraldehyde and hydrogenation to 90% of 2-propylheptanol with 10% 2-propyl-4-methylhexanol and subsequent esterification with phthalic anhydride recovered. This produces phthalic acid esters with C ₁₀ alcohol in a proportion of> 99.5% .

properties

Main structural isomer of DPHP - stereoisomers -
( R , R ) stereoisomer
( S , S ) stereoisomer
meso stereoisomer

Bis (2-propylheptyl) phthalate is a flammable, hardly inflammable, non-volatile, colorless liquid that is practically insoluble in water. It decomposes when heated. Due to the two branched C ₁₀ side chains, it is an isomer of didecyl phthalate (e.g. DIDP ). Just like DIDP - a technical mixture of phthalates with differently branched C chains (essentially C ₉ to C ₁₁ chains) - DPHP is a mixture of several isomeric phthalic acid esters. The technical product consists of about 81% bis (2nd -propylheptyl) phthalate, 18% 2-propylheptyl-2-propyl-4-methylhexyl-phthalate and 1% bis (2-propyl-4-methylhexyl) phthalate, with purities above 99.5% also available. However, the latter are still mixtures of stereoisomers.

Stereoisomerism

The main structural isomer bis (2-propylheptyl) phthalate, which is around 81% in the technical product, is not a pure substance, but a mixture of three stereoisomers:

• ( R , R ) -Bis (2-propylheptyl) phthalate,
• ( S , S ) -Bis (2-propylheptyl) phthalate and
• meso -bis (2-propylheptyl) phthalate.

use

Bis (2-propylheptyl) phthalate is used as a plasticizer in PVC, polyurethane and epoxy resin adhesives. The end products are primarily cables and wires, roof sheeting, car interior linings, tarpaulins, materials for car underbody protection, the construction sector, as well as for shoes, carpet backing, swimming pool linings, gloves, pressure-sensitive adhesives, printing inks, corrosion protection paints, anti-fouling paints and as lubricant components. However, the supervisory authorities of the federal states have also detected DPHP in toys. It is possible that some toy manufacturers are making increasing use of this plasticizer because its use is not yet restricted under the REACH regulation. Typical concentrations of DPHP in the end product are between 30 and 60%.

safety instructions

The acute toxicity of DPHP is low. In studies of the irritating and corrosive effects on the skin and eyes in rabbits, DPHP has proven to be slightly irritating. If only exposure to DPHP from toys is considered in children, there is no health risk on the basis of the No Observed Adverse Effect Level ( NOAEL , highest dose at which no toxic effect occurs) and a safety factor of 100 based on animal experiments . Since children come into contact with the plasticizer not only through toys, but also through other products and the substance has proven to be harmful to the thyroid and pituitary glands in animal experiments , the Federal Institute for Risk Assessment considers it necessary to withstand the exposure of children Decrease DPHP from toys.

Bis (2-propylheptyl) phthalate was included by the EU in 2014 in accordance with Regulation (EC) No. 1907/2006 (REACH) as part of substance evaluation in the Community's ongoing action plan ( CoRAP ). The effects of the substance on human health and the environment are re-evaluated and, if necessary, follow-up measures are initiated. The uptake of bis (2-propylheptyl) phthalate was caused by concerns about exposure of sensitive population groups , high (aggregated) tonnage and widespread use and as a potential endocrine disruptor . The reassessment is to be carried out by Germany from 2020 .

literature

• Substance monograph for di-2-propylheptyl phthalate (DPHP) - human biomonitoring (HBM) values ​​for the sum of the metabolites oxo-monopropyl heptyl phthalate (oxo-MPHP) and hydroxy-monopropyl heptyl phthalate (OH-MPHP) in the urine of adults and children. In: Federal Health Gazette - Health Research - Health Protection. 58, 2015, p. 774, doi : 10.1007 / s00103-015-2172-z .

Individual evidence

1. ↑ ^{a b c d e f g h i} Entry on bis (2-propylheptyl) phthalate in the GESTIS substance database of the IFA , accessed on June 16, 2017(JavaScript required) .
2. ↑ ^{a b c} MAK: Di (2-propylheptyl) phthalate , 58th delivery, 2015, DOI: 10.1002 / 3527600418.mb5330654d0058
3. ↑ ^{a b c d e} Federal Institute for Risk Assessment: DPHP detected in toys: BfR assesses the risk of plasticizers BfR opinion No. 004/2012 of June 28, 2011 , accessed on June 16, 2017.
4. ↑ Anna Wypych: Databook of Plasticizers . Elsevier, 2017, ISBN 978-1-927885-15-4 , pp. 502 ( limited preview in Google Book search).
5. ↑ Community rolling action plan ( CoRAP ) of the European Chemicals Agency (ECHA): Bis (2-propylheptyl) phthalate , accessed on March 26, 2019.