Dibutyl phthalate

Structural formula
General
Surname	Dibutyl phthalate
other names	Dibutyl phthalate DBP Butyl phthalate Elaol Dibutylbenzene-1,2-dicarboxylate Di-n-butyl phthalate
Molecular formula	C 16 H 22 O 4
Brief description	colorless to yellowish oily liquid with a slightly aromatic odor
External identifiers / databases
CAS number 84-74-2 EC number 201-557-4 ECHA InfoCard 100.001.416 PubChem 3026 Wikidata Q415612
Drug information
ATC code	P03 BX03
properties
Molar mass	278.34 g mol −1
Physical state	liquid
density	1.05 g ml −1
Melting point	−35 ° C
boiling point	340 ° C
Vapor pressure	0.026 µbar (20 ° C) 0.07 µbar (30 ° C) 0.755 µbar (50 ° C)
solubility	practically insoluble in water (10 mg l −1 at 20 ° C)
safety instructions
Please note the exemption from the labeling requirement for drugs, medical devices, cosmetics, food and animal feed GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary danger H and P phrases H: 360Df-400 P: 201-280-308 + 313
Authorization procedure under REACH	of particular concern : toxic for reproduction ( CMR ), serious effects on human health are considered probable; subject to approval
MAK	Switzerland: 0.05 ml m −3 or 0.58 mg m −3
Toxicological data	7500 mg kg −1 ( LD 50 ,  rat ,  oral )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Dibutyl phthalate (abbreviation DBP) is a chemical compound with an aromatic odor and a colorless, oily liquid. It is an ester of 1-butanol and phthalic acid and thus belongs to the group of phthalates in addition to diethylhexyl phthalate , di- iso- nonyl phthalate , dimethyl phthalate and diethyl phthalate . It is used industrially as a plasticizer .

Presentation and extraction

The technical production of dibutyl phthalate takes place in a two-stage synthesis from phthalic anhydride and n- butanol . The first step is rapid alcoholysis to form the phthalic acid half-ester. The second esterification step is slower as an equilibrium reaction and requires the use of acidic catalysts and, in order to complete the conversion, the distillative separation of the water formed.

properties

Physical Properties

Dibutyl phthalate is a colorless liquid with a melting point of −35 ° C. The boiling point under normal pressure is 340 ° C. The enthalpy of vaporization here is 91.7 kJ mol ⁻¹ . According to Antoine, the vapor pressure curve results in the temperature range from 398.8 K to 475.2 K as log ₁₀ ( p ) = A - ( B / ( T + C )) ( p in bar, T in K) with A = 4, 30568, B = 2083.175 and C = −131.7. The heat capacity at 25 ° C is 476 J mol ⁻¹ K ⁻¹ or 1.71 J g ⁻¹ K ⁻¹ . The compound is only slightly soluble in water at 11 mg · l ⁻¹ .

Safety-related parameters

Dibutyl phthalate only forms flammable vapor-air mixtures at higher temperatures. The compound has a flash point of 157 ° C. The explosion range is between 0.1 vol.% As the lower explosion limit (LEL) and 1.97 vol.% As the upper explosion limit (UEL). It is assigned to explosion group IIA. The ignition temperature is 400 ° C. The substance therefore falls into temperature class T2. The electrical conductivity is rather low at 1.8 · 10 ⁻⁷ S · m ⁻¹ (30 ° C). When burned, irritating, corrosive and toxic fumes are generated.

use

DBP is mainly used as a plasticizer for PVC and as an absorbent (washing liquid) for cleaning gas mixtures and organic compounds. It is also used as an additive in drug casings so that the ingredients do not dissolve in the stomach, but only in the intestine. These include drugs for colds, bronchitis, asthma, sleep disorders, high cholesterol levels and iron deficiency.

toxicology

Inhalation or swallowing can damage health and cause temporary symptoms such as dizziness, nausea, headache, etc. Ingestion can irritate the respiratory tract, digestive tract and eyes. B. Burning, scratching. In animal experiments, dibutyl phthalate has a developmental, reproductive and embryotoxic effect . The European Union classifies dibutyl phthalate as "toxic to reproduction" and has set a TDI value ("tolerable daily intake") of 10 micrograms per kilogram of body weight (since July 2005, previously 100 micrograms). The World Health Organization (WHO) classifies DBP as "harmful to fruit and development". It is very toxic to aquatic organisms and can have long-term adverse effects in the aquatic environment - it is hazardous to water (WGK 2) and a marine pollutant.

In a Danish cohort study in 2019, an increase in the risk of estrogen receptor positive (ER +) breast cancer was observed, which was doubled at the highest exposure. A direct correlation was observed between the level of exposure and the increased risk. Exposure took place via the ingestion of phthalate-containing drugs (mesalazine, budesonide, lithium and bisacodyl, phthalates: dibutyl phthalate, cellulose acetate phthalate, hypromellose phthalate and polyvinyl acetate phthalate). The exposure data came from the Danish drug registry, the disease data from the Danish cancer registry. The observation period was from 2005 to 2018. 1.12 million women were observed, 14% of the women were exposed to the pharmaceuticals, and 27,111 cases of breast cancer occurred during the observation period.

In accordance with the German Cosmetics Ordinance and Consumer Goods Ordinance , DBP is prohibited in baby items, cosmetics and toys .

On March 31, 2015, dibutyl phthalate was added to the RoHS substance list with Directive (EU) 2015/863. As of July 22, 2019, electrical and electronic equipment containing parts with more than 0.1% by weight of DBP in the homogeneous material may no longer be sold in the EU.

Individual evidence

1. ↑ ^{a b c d e f g h i j k l m n o} Entry on dibutyl phthalate in the GESTIS substance database of the IFA , accessed on January 9, 2019(JavaScript required) .
2. ↑ Entry on dibutyl phthalate in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
3. ↑ Entry in the SVHC list of the European Chemicals Agency , accessed on July 7, 2017.
4. ↑ Entry in the register of substances subject to authorization of the European Chemicals Agency , accessed on July 7, 2017.
5. ↑ Swiss Accident Insurance Fund (Suva): Limits - Current MAK and BAT values (search for 84-74-2 or dibutyl phthalate ), accessed on November 2, 2015.
6. ↑ ^{a b} P.M. Lorz, FK Towae, W. Enke, R. Jäckh, N. Bhargava, W. Hillesheim: Phthalic Acid and Derivatives in Ullmann's Encyclopedia of Industrial Chemistry, 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, doi : 10.1002 / 14356007 .a20_181.pub2 .
7. ↑ ^{a b} Buckingham, J .; Donaghy, SM, Dictionary of Organic Compounds: Fifth Edition, Chapman and Hall, New York, 1982, 1.
8. ↑ Birks, J .; Bradley, RS: The rate of evaporation of droplets. II. The influence of changes of temperature and of the surrounding gas on the rate of evaporation of drops of di-n-butyl phthalate in Proc. Roy. Soc. London A 198 (1949) 226-239.
9. ↑ Hammer, E .; Lydersen, AL: The Vapor Pressure of di-n-Butylphthalate, di-n-Butylsebacate, Lauric Acid and Myristic Acid in Chem. Eng. Sci. 7 (1957) 66-72.
10. ↑ Rabinovich, IB; Novoselova, NV; Moseeva, EM; Babinkov, AG; Tsvetkova, L.Ya .: Low temperature specific heat and thermodynamic functions of dibutyl and dioctyl phthalate in Zhur. Fiz. Khim. 59 (1985) 2127-2130.
11. ^ ^{A b} E. Brandes, W. Möller: Safety-related parameters - Volume 1: Flammable liquids and gases , Wirtschaftsverlag NW - Verlag für neue Wissenschaft GmbH, Bremerhaven 2003.
12. ↑ Technical rule for operational safety - TRBS 2153, BG RCI leaflet T033 Avoidance of ignition hazards due to electrostatic charges , as of April 2009, Jedermann-Verlag Heidelberg.
13. ↑ Allum: Phthalate-based plasticizers Status: March 2012.
14. ^ Arbeitsgemeinschaft PVC und Umwelt eV: Market data plasticizers ( Memento of the original from December 3, 2013 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 35 kB). 
15. ↑ German-French Institute for Environmental Research (DFIU): Report on Best Available Techniques (BAT) in the field of paint and adhesive processing in Germany (August 2002; PDF; 3.6 MB), Appendix V.
16. ↑ Thomas P. Ahern, Anne Broe, Timothy L. Lash, Deirdre P. Cronin-Fenton, Sinna Pilgaard Ulrichsen: Phthalate Exposure and Breast Cancer Incidence: A Danish Nationwide Cohort Study . In: Journal of Clinical Oncology . April 17, 2019, p. JCO.18.02202 , doi : 10.1200 / JCO.18.02202 .
17. ↑ EUR-Lex - 32015L0863 - EN - EUR-Lex. Retrieved July 2, 2019 .