823R78001 PHTHALATE ESTERS Ambient Water Quality Criteria Criteria and Standards Division Office of Water Planning and Standards U.S. Environmental Protection Agency Washington, D.C. ------- CRITERION DOCUMENT PHTHALATE ESTERS CRITERIA Aquatic Life For freshwater aquatic life, no criterion for any phthalate ester can be derived using the Guidelines, and there are insuffi- cient data to estimate a criterion using other procedures. For saltwater aquatic life, no criterion for any phthalate ester can be derived using the Guidelines, and there are insuffi- cient data to estimate a criterion using other procedures. Human Health For the protection of human health from the toxic properties of phthalate esters ingested through water and through contami- nated aquatic organisms, the ambient water criteria for dimethyl phthalate and diethyl phthalate are determined to be 160 mg/1 and 60 mg/1, respectively. The water quality criteria for dibutyl phthalate and di-2-ethylhexyl phthalate are determined to be 5 mg/1 and 10 mg/1, respectively. ------- Introduction Phthalic acid esters or "phthalate esters" represent a large family of chemicals widely used as plasticizers, pri- marily in the production of polyvinyl chloride (PVC) resins (U.S. Int. Trade Comm. 1977). Phthalates are esters of the ortho form of benzenedicarboxylic acid also referred to as ortho-phthalic acid. Two other isomeric forms of phthalic acid esters are also produced. These include the meta form (or isothalate esters) and the para form (or terephthalate esters). Both of these isomers have a number of important commercial applications such as starting materials for plas- tics and textiles. In this document, however, consideration will be given only to the ortho-phthalate esters. The annual production of phthalic acid esters in the United States in 1977 amounted to approximately 1.2 billion pounds. Since 1945, the cumulative total production (up to 1972) of these esters reached a figure of 12.5 billion pounds (Peakall, 1975). On a worldwide scale, three to four billion pounds are produced annually. The most widely used phthalate plasticizer is di (2- ethylhexyl) phthalate (DEHP), which accounted for an esti- mated 32 percent of the total phthalate esters produced in 1977 (U.S. Int. Trade Comm. 1978). In addition to DEHP, other phthalates produced included other dioctyl phthalates, butylbenzyl phthalate (BBP) diisodecyl phthalate, dibutyl phthalate (DBF) diethyl phthalate (DEP), dimethyl phthalate (DMP), di-tridecyl phthalate and n-hexyl n-decyl phthalate (U.S. Int. Trade Comm. 1978). A-l ------- PVC resins are used in such diverse industries as con- struction (high temperature electrical wire, cable insula- tion, and flooring), home furnishings (furniture upholstery, wall coverings) transportation (upholstery and seat covers) apparel (footwear) and food and medical packaging materials. Phthalates also have non-plasticizer uses in pesticide car- riers, cosmetics, fragrances, munitions, industrial oils, and insect repellants (U.S. Int. Trade Comm. 1978). PAE plasticizers can be present in concentrations up to 60 percent of the total weight of the plastic. The plasti- cizers are loosely linked to the plastic polymers and are easily extracted (Mathur, 1974). For the most part, the esters are colorless liquids, have low volatility, and are poorly soluble in water but soluble in organic solvents and oils. The phthalate esters can be prepared by reaction of phthalic acid with a specific alcohol to form the desired esters. In industry, however, the esters are manufactured from phthalic anhydride rather than from the acid. For the most part, manufactured esters will not be completely pure, having various isomers and contaminants present. These esters, however, can be prepared with a purity of greater than 99 percent even though most of these esters are not sold with this high degree of purity. Evidence also is available suggesting that certain plants and animal tissue may synthesize phthalic acid esters (Peakall, 1975). However, to what extent this occurs in nature is not known. A-2 ------- The ease of extraction of phthalate esters and their widespread use in PVC or alone account for their ubiquity. PAEs have been detected in soil (Ogner and Schnitzer, 1970), water (Ewing and Chian, 1977; Corcoran, 1973; Kites and Bieman, 1972) fish (Mayer, 1976; Stalling, 1973) air (Mathur, 1974) and animal and human tissues (Nazir, et al. 1971; Rubin and Shiffer, 1976; Jaeger and Rubin, 1970). Their detection in certain vegetation, animals and minerals (Mathur, 1974; Graham, 1973), and in areas remote from industrial sites (Carpenter and Smith, 1972) have raised questions about pos- sible natural origins of PAEs. PAEs found in greatest fre- quencies in an EPA monitoring survey of U.S. surface waters (Ewing and Chian, 1977) were DEHP (132/204) and DEP (84/204). Other esters detected in the EPA survey were diethyl phthal- ate, disobutyl phthalate, and diocyl phthalate. PAEs have been reported to be acutely and chronically toxic to freshwater and marine aquatic organisms (U.S. EPA, 1978; Mayer and Sanders, 1973). Levels of PAE residues de- tected in fish 'from ambient waters have not been correlated with adverse biological effects (Johnson, et al. 1974). Data show that phthalate esters can be chronically toxic to aqua- tic organisms at low concentrations. DEHP impairs reproduc- tion in Daphnia magna by 60 percent at a concentration as low as 3 uq/1 (Mayer and Sanders, 1973). Toxicological investi- gations in mammals show that phthalates have low acute toxi- cities but induce serious chronic effects including terato- genicity and mutagenicity (Peakall, 1975). A-3 ------- Due to their large production volumes, ubiquity, and toxicity to aquatic organisms and mammals, PAE levels in water should be controlled to prevent potential hazards to man and aquatic life. A-4 ------- REFERENCES Carpenter, E., and K. Smith. 1972. Plastics on the Sargasso sea surface. Science 175: 1240. Cocoran, E. 1973. Gas chromatographic detection of phthalate acid esters. Environ. Health Perspect. 3: 13. Ewing, B., and E. Chian. 1977. Monitoring to detect pre- viously unrecognized pollutants in surface waters. EPA 560/7-77/15a. Off. Tox. Subst. U.S. Environ. Prot. Agency, Washington, D.C. Graham, P. 1973. Phthalate ester plasticizers - why and how they are used. Environ. Health Perspect. 3: 3. Kites, R., and K. Bieman. 1972. Water pollution - organic compounds in the Charles River, Boston. Science 178: 158. Jaeger, R., and R. Rubin. 1970. Plasticizers from plastic derivatives. Exhaustion, metabolism, and accumulation by biological systems. Science 170: 460. Johnson, B., et al. 1974. Dynamics of phthalic acid esters in aquatic organisms. Page 283. In I.E. Suffet, ed., Fate of pollutants in air and water environments. Part 2. Wiley Interscience Publishers, New York. A-5 ------- Mathur, S. 1974. Phthalate esters in the environment: Pol- lutants or natural products? Jour. Environ. Quality 3: 189. Mayer, F.L. 1976. Residue dynamics of di-2-ethylhexylphthal- ate in fathead minnows, Pimephales promelas. Jour. Fish. Res. Board Can. 33: 2610. Mayer, F.L. Jr., and H.O. Sanders. 1973. Toxicology of phthalic acid esters in aquatic organisms. Environ. Health Perspect. 3: 153. Nazir, D., et al. 1971. Isolation, identification, and spe- cific localization of di-2-ethylhexyl phthalate in bovine heart muscle mitochondria. Biochemistry 10: 4425. Ogner, G., and M. Schnitzer. 1970. Humic substances: Fulvic acid - dialkyl phthalate complexes and their role in pollu- tion., Science 170: 317. Peakall, D. 1975. Phthalate esters: Occurence and biological effects. Residue Rev. 54: 1. Rubin, R., and C. Schiffer. 1976. Fate in humans of the plasticizer, di-2-ethylhexyl phthalate, arising from plate- lets stored in vinyl plastic bags. Transfusion 16: 330. Stalling, D., et al. 1973. Phthalate ester residues - their metabolism and analysis in fish. Environ. Health Perspect. 3: 159. ' U A-6 ------- U.S. EPA. 1978. In-depth studies on health and environmental impacts of selected water pollutants. Contract No. 68-01- 4646. U.S. International Trade Commission. 1978. Synthetic organic chemicals, U.S. production and sales. Washington, D.C. A-7 ------- AQUATIC LIFE TOXICOLOGY* FRESHWATER ORGANISMS Introduction A limited number of applicable reports were found having data fcr the effects of phthalate esters on freshwater aquatic life. More information is available for di-n-butyl and di-2- ethylhexyl phthalate than for other esters. Acute Toxicity All acute values were determined with static procedures and the test concentrations were unmeasured. Data for five phthalate esters are in Tables 1 and 2. Values for four of the esters were from tests with both fish and invertebrate species. The Final Invertebrate Acute Value of 450 ug/1 for di-2- ethylhexyl phthalate is derived from a test with Daphnia magna. Additional acute data for this ester are in Table 6, but the LC50 values for the bluegill and scud exceeded the highest concentra- tions tested. *The reader is referred to the Guidelines for Deriving Water Quality Criteria for the Protection of Aquatic Life [43 FR 21506 (May 18, 1978) and 43 FR 29028 (July 5, 1978)] in order to better understand the following discussion and recommendation. The following tables contain the appropriate data that were found in the literature, and at the bottom of each table are the calcula- tions for deriving various measures of toxicity as described in the Guidelines. B-l ------- Tests with butylbenzyl, diethyl and dimethyl phthalates were conducted with both bluegill and Daphnia magna by the U.S. EPA (1978). For both species the adjusted LC50 values are within one order of magnitude and range from 23,672 to 78,200 ug/1' The Final Acute Values were from the invertebrate tests and are 3,700, 2,100, and 1,300 ug/1, respectively. Acute di-n-butyl phthalate tests were conducted with four fish species. The adjusted LC50 values vary from 399 to 3,537 ug/1 or by about nine times. Bluegills were the most sensitive fish species tested with this ester. The Final Acute Value was 85 ug/1 and derived from the scud invertebrate test since it was the lowest obtained value. An additional acute datum for this ester is in Table 6, but the LC50 value exceeded the highest test con- centration. Chronic Toxicity A di-2-ethylhexyl phthalate embryo-larval test was conducted with rainbow trout (Table 3). The lowest adverse effect concen- tration from this flow-through test was 14 ug/l« The Final Fish Chronic Value (0.63 ug/1) is obtained by dividing the chronic value (4.2 ug/1) by the sensitivity factor (6.7). Mayer and Sanders (1973) conducted a chronic test with di-2- ethylhexyl phthalate and Daphnia magna. Significant reproductive impairment was found at 3 ug/1 (Table 4). Since this value was at the lowest test concentration, the adverse effects on reproduction were less than 3 ug/1. After this concentration is divided by the species sensitivity factor (5.1) a Final Invertebrate Chronic Value of less than 0.59 ug/1 is obtained. This concentration is B-2 ./ ------- lower than the comparable value for fish or any plant effects and, since there is no Residue Limited Toxicant Concentration, the Final Chronic Value for di-2-ethylhexyl phthalate is less than 0.59 ug/l<> Plant Effects The adverse effects of three phthalate esters on the alga, Selenastrum capricornutumy have been determined (Table 5). Simi- lar EC50 values were found for cell numbers and chlorophyll a_ for each ester tested. The lowest EC50 values for diethyl and di- methyl phthalate were 85,600 and 39,800 v.g/1, respectively. A much lower EC50 value of 110 ug/1 was obtained with butylbenzyl phthalate. By comparison^ the adjusted LC50 values found in Tables 1 and 2 for all three of these esters were within a factor of 4. Residues , Bioconcentration factors for five phthalate esters have been reported (Table 6). Mayer (1976) measured both the actual concen- trations and 14C-labeled di-2-ethylhexyl phthalate in a test system and found that the difference was less than two times after equilibrium in fathead minnows,, Bioconcentration factors for 14C-labeled butylbenzyl- phthalate, diethyl phthalate, and dimethyl phthalate and bluegills were 663, 117, and 57, respectively after a 21-day exposure (U.S. EPA, 1978)„ The half-life of these three phthalate esters was between 1 and 2 days- Bicaccumulation data with di-n-octyl phthalates by Sanborn, et al. (1975) in a static model ecosystem are found in Table 7. B-3 ------- Their water concentrations rapidly decreased with time and do not permit comparisons with values in Table 6. Since no maximum permissible tissue levels exist for phthal- ate esters, no Residue Limited Toxicant Concentration could be calculated for any phthalate ester. Miscellaneous Additional toxicity data for phthalate esters can be found in Table 6. Many of these data have been discussed and do not alter the final acute or chronic values. Mayer, et al. (1977) exposed rainbow trout eggs to di-2-ethylhexyl phthalate for 90 days and found concentrations of 14 and 54 ug/1 significantly increased total protein catabolism 24 days after hatching. This concentra- tion range is similar to the lowest adverse test concentration found with this ester in the embryo-larval test (Table 3). B-4 ------- CRITERION FORMULATION Freshwater-Aquatic Life gummary of Available Da.ta All concentrations below have been rounded to two significant figures„ butylbenzyl phtha3.ate Final Fish Acute Vaj.ue = 5,100 ug/1 Fir.:.'. Invertebrate Acute Value = 3,700 ug/1 Final Acute Value = 3,700 ug/1 Final Fish Chronic \ r>juie = not available Final Invertebrate Chronic Value - not available Final Plant Value = 110 ug/1 Re3idua Limited Toxicant Concentration = not available Final Chronic Value - 110 ug/1 0<,44 x Final Acute Value = 1,600 ug/1 dj.ethyl phthalate Final Fish Acute Value = 14,000 ug/1 final Invertebrate Acute Value = 2,100 ug/1 Final Acute Value = 2,100 ug/1 Final Fish Chronic Value = not available Final Invertebrate Chronic Value = not available Final Plant Value = 86^000 ug/1 Residue Limited Toxicant Concentration = not available Final Chronic Value = 86,000 ug/1 Oo44 x Final Acute Value = 920 ug/1 dimethyl phthalate Final Fish Acute Value = 6,900 ug/1 Final Invertebrate Acute Value = 1,300 ug/1 ------- Final Acute Value = 1,300 ug/1 Final Fish Chronic Value = not available Final Invertebrate Chronic Value = not available Final Plant Value = 39,000 ug/1 Residue Limited Toxicant Concentration = not available Final Chronic Value = 39,000 ug/1 0.44 x Final Acute Value = 570 ug/1 di-n-butyl phthalate Final Fish Acute Value = 310 ug/1 Final Invertebrate Acute Value = 36 y.g/1 Final Acute Value = 36 ug/1 Final Fish Chronic Value = not available Final Invertebrate Chronic Value = not available Final Plant Value = not available Residue Limited Toxicant Concentration = not available Final Chronic Value = not available 0.44 x Final Acute Value = 16 ug/1 di-2-ethylhexylphthalate Final Fish Acute Value = not available Final Invertebrate Acute Value = 450 ug/1 Final Acute Value = 450 ug/1 Final Fish Chronic Value =0.63 ug/1 Final Invertebrate Chronic Value = less than 0.59 ug/1 Final Plant Value = not available Residue Limited Toxicant Concentration = not available Final Chronic Value = less than 0.59 ug/1 0.44 x Final Acute Value = 200 ug/1 B-6 ------- No freshwater criterion can be derived for any phthalate ester using the Guidelines because no Final Chronic Value for either fish or invertebrate species or a good substitute for either value is available, and there are insufficient data to estimate a criterion using other procedures. B-7 ------- Table 1. Freshwater fish acute values for phthalate esters DO I 00 Organism Bluegill. Lfcpomis macrochirus Bluegill, Lepomis macrochirus Bluegill, Lepomis macrochirus Rainbow trout, Salmo gairdneri Fathead minnow, Pimephales promelas Channel catfish, Ictalurus punctatus Bluegill, Lepomis macrochirus Bluegill, Lepomis macrochirus Bioaseay Test Time LC50 Method" Cone.** (hrs^ (uq/11 Butylber.zyl phthalate S U 96 43,300 Diethyl phthalate S U 96 98,200 Dimethyl phthalate S U 96 49,500 S S S S S di-n-butyl phthalate U 96 6.470 U U U U 96 96 96 96 1.300 2.910 730 1.200 Adjusted LC50 (uq/11 Keference 23,672 U.S. EPA. 1978 53.686 U.S. EPA. 1978 27,062 U.S. EPA, 1978 3,537 Mayer & Sanders, 1973 711 Mayer fi. Sanders, 1973 1,591 Mayer & Sanders, 1973 399 Mayer & Sanders, 1973 656 U.S. EPA, 1978 * S » static ** U = unmeasured Geometric mean of adjusted values: butylbenzyl phthalate = 23,672 yg/1 diethyl phthalate = 53,686 pg/1 dimethyl phthalate = 27.062 ug/1 di-n-butyl phthalate = 1,196 ,ig/l = 6,100 wg/1 14,000 i'g/1 6,900 pg/1 310 Mg/1 ------- Table 2. Freshwater invertebrate acute values for phthalate esters DO I Cladoceran, Daphnia maena Cladoceran, Daphnia maena Cladoceran, Daphnia magna Cladoceran, Daphnia maena Scud, Gammarus pseudolimnaeus biocissay Test Time LC50 MetliQU* C O HC ." * (HIS) (Uq/J Butylbenzyl phthalate S U 48 92.300 Diethyl phthalate S U 48 52,100 Dimethyl phthalate S U 48 33,000 di-2-ethylhexylphthalate S U 48 11,100 di-n-butyl phthalate S U 48 2.100 Adjusted LCbU (uq/i) Ketfcience 78.200 U.S. EPA, 1978 44,100 U.S. EPA, 1978 28,000 U.S. EPA, 1978 9,400 U.S. EPA, 1978 765 Mayer & Sanders, 1973 * S = static ** U = unmeasured Geometric mean of adjusted values: butylbenzyl phthalate = 78,200 \ig/l 78A200 = 3,700 Pg/1 diethyl phthalate = 44,100 wg/1 ^^M = 2,100 pg/1 dimethyl phthalate = 28,000 yg/1 28P° = 1,300 pg/1 di-2-ethylhexylphthalate = 9,400 pg/1 = 450 yg/1 ~ di-n-butyl pththalate = 765 Mg/1 ~2T = 36 ng/1 ------- Table 3. Freshwater fish chronic values for phthalate esters (Mehrle & Mayer, 1976) Chronic Limits Value Organism Test* (ng/i) (tui/i) di-2-ethylhexylphthalate Rainbow trout. E-L 5-14 4.2 Salmo gairdneri * E-L = embryo-larval 4.2 Geometric mean of chronic values = 4.2 yg/1 7—•= = 0.63|iJg/l Lowest chronic value = 4.2 yg/1 CD I ------- Table 4. Freshwater invercebrace chronic values for phthalate esters (Mayer & Sanders, 1973) Organism Cladoceran, Daphnia magna Chronic Limits Value Test* (uq/i) (uq/i) di-2-ethylhexylphthalate LC <3.0 <3.0 * LC = life cycle Geometric mean of chronic values = <3.0 yg/1 Lowest chronic value = <3.0 yg/1 <3.0 *0.59 pg/1 DO I ------- Table 5. Freshwater plant effects for phthalate esters (U.S. EPA. 1978) Organism Effect Concentration (UR/I) Butylbenzyl phthalate DO \-> NJ Alga, Selenastrum capricornutum Alga, Selenastrum capricornutum Alga, Selenastrum capricornutum Alga, Selenastrum capricornutum Alga, Selenastrum capricornutum Alga, Selenastrum capricornutum EC50 96-hr chlorophyll a EC50 96-hr cell number 110 130 Diethyl phthalate 90,300 EC50 96-hr chlorophyll a EC50 96-hr cell number 85,600 Dimethyl phthalate 42,700 EC50 96-hr chlorophyll a EC50 96-hr cell number 39,800 Lowest plant value: butylbenzyl phthalate = 110 pg/1 diethyl phthalate = 85,600 ng/1 dimethyl phthalate = 39,800 pg/1 ------- Table 6. Freshwater residues for phthalate esters 00 M U> Organism Cladoceran, Daphnla magna Scud, Gammarus pseudolimnaeus Scud, Gammarus pseudolimnaeus Sowbug , Asellus brevicaudus Rainbow trout, Salmo gairdneri Fathead minnow, Pimephales promelas Fathead minnow, Pimephales promelas Bluegill, Lepomis macrochirus Bluegill, Lepomis macrochirus Bluegill, Lepomis macrochirus Bioconcentration Factoi* di-n-butyl phthalate 400 1,400 di-2-ethylhexylphthalate 54-2,680--* 14-50** 42-113 155-886 91-569*** butylbenzylphthalate 663 diethylphthalate 117 dimethylphthalate 57 Time (days) 14 14 14-21 21 36 56 56 21 21 21 neterence Mayer & Sanders Mayer & Sanders Sanders, et al . Sanders, et al. Mehrle & Mayer, Mayer, 1976 Mayer, 1976 U.S. EPA. 1978 U.S. EPA, 1978 U.S. EPA, 1978 , 1973 , 1973 1973 1973 1976 Based on total l>tC radioactivity accumulated. "*" Conversion from dry to wet weight. ***Based on measured concentrations of di-2-ethylhexylphthalate. ------- Organism Table 7. Other freshwater data'for phthalate esters Test Duration Ettect Result (ug/1) Retereiicfe di-2-ethylhexylphthalate Scud, 96 hrs LC50 Gammarus pseudolimnaeus >32.000 Sanders, et al. 1973 DO I Rainbow trout, Saltno gairdneri Guppy, Poecilla reticulatus Bluegill, Lepomis macrochlrus Crayfish, Orconectes nais Alga, Oedogonium cardiacum Cladoceran, Daphnia maena Mosquito (larva), Culex pipeus quinquefasciatus Snail, Physa sp Mosquitofish, Gambusia affinis 24 days Significant increase 14-54 in total body protein catabolism 90 days Incre'ase in aborted young 96 hrs LC50 di-n-butyl phthalate 96 hrs LC50 di-n-octyl phthalate 33 days Model ecosystem* 28.500X bioconcentration 33 days Model ecosystem* 2.600X bioconcentration 33 days Model ecosystem* 9.400X bioconcentration 33 days Model ecosystem* 13.600X bioconcentration 33 days Model ecosystem* 9.400X bioconcentration Mayer, et al. 1977 fed 100 Mayer & Sanders, 1973 ug/g in diet >770.000 U.S. EPA, 1978 >10,000 Mayer & Sanders. 1973 Sanborn, et al. 1975 Sanborn, et al. 1975 Sanborn, et al. 1975 Sanborn, et al. 1975 Sanborn, et al. 1975 * Based on actual concentrations of di-n-octyl-phthalate accumulated ------- SALTWATER ORGANISMS Introduction Phthalate esters have contaminated various segments of our en- vironment, including aquatic organisms and water (Mayer and Sanders, 1973), and there is a growing concern that they may be a menace to health and to our ecological system. Phthalate esters are a large group of chemical agents (esters of ortho benzene dicarboxylic acid) used primarily as plasticizers. Toxicity test data for saltwater organisms are available for only four phthalate esters. Laughlin, et al. (1977) conducted studies on the effects of di-n-butyl phthalate and dimethyl phthalate on development of the mud crab, Rhithropanopeus harrisii. All other data (U.S. EPA, 1978) consist of LC50 or EC50 values based on static tests and unmeasured concentrations for three species (sheepshead minnow, Cyprinodon variegatus; mysid shrimp, Mysidopsis bahia; and an alga, Skeletonema costatum) for butylbenzyl phthalate, diethyl phtha- late, and dimethyl phthalate. These data indicate great differences in toxicity among esters; therefore, it would be inappropriate to gener- ate a criterion for phthalate esters as a group. Acute Toxicity Butylbenzyl phthalate and diethyl phthalate were less toxic to the sheepshead minnow than they were to the mysid shrimp; dimethyl phthalate was more toxic (Tables 8 and 9). Unadjusted 96-hour LC50 values for butylbenzyl, diethyl, and dimethyl phthalates for the sheepshead minnow were 445,000, 29,600, and 58,000 ug/1, respectively, B-15 ------- and for the mysid shrimp, 9,630, 7,590, and 73,700 ug/1/ respectively (U.S. EPA, 1978). When the geometric means of the adjusted LC50 values for fishes are divided by the species sensitivity factor (3.7), the resultant Final Fish Acute Values are 66,000 ug/1 for butylbenzyl phthalate, 4,400 ug/1 for diethyl phthalate, and 8,600 ug/1 for dimethyl phthalate (Table 8). The geometric means of the adjusted LC50 values for inver- tebrate species, when divided by the species sensitivity factor (49), give Final Invertebrate Acute Values of 170 ug/1 for butylbenzyl phthalate, 130 ug/1 for diethyl phthalate, and 1,300 ug/1 for dimethyl phthalate. Freshwater acute toxicity data (Tables 1 and 2) for butyl- benzyl, diethyl, and dimethyl phthalates showed that toxicity to fresh- water fish and invertebrate species did not differ greatly from that to saltwater animals, although relative sensitivity of freshwater fish and invertebrate species to phthalate esters usually differed from salt- water organisms. Chronic Toxicity No saltwater fish or invertebrate species has been tested in a chronic toxicity study. Plant Effects Butylbenzyl phthalate and dimethyl phthalate were more toxic to a saltwater alga, Skeletonema costatum, than to the tested fish and invertebrate species; diethyl phthalate was less toxic (Table 10). Butylbenzyl phthalate was particularly toxic to the alga: a concen- tration of 170 ug/1 caused 50 percent reduction in chlorophyll a_ and 190 ug/1 caused 50 percent reduction in cell numbers in 96 hours (U.S. EPA, 1978). Freshwater data (Table 5) also indicated that a fresh- water alga was especially sensitive to butylbenzyl phthalate. The B-16 ------- 96-hour EC50 values for Skeletonema costatum exposed to dimethyl phthalate were 26,100 ug/1 for chlorophyll a and 29,800 ug/i for cell numbers. Exposure to diethyl phthalate resulted in a 96-hour EC50 of 65,500 ug/1 for chlorophyll a and a 96-hour EC50 of 85,000 ug/1 for cell numbers (U.S. EPA, 1978). Residues No data for bioconcentration of phthalate esters by saltwater species are available. Miscellaneous In laboratory experiments by Laughiin, et al. (1977), 1,000 ug/1 di-n-butyl phthalate or dimethyl phthalate had no significant effect on the entire larval development of the mud crab, Rhithropanopeus harrisii (Table 11). There are no other saltwater data that suggest more sen- sitive effects than those already presented. B-17 ------- CRITERION FORMULATION Saltwater-Aquatic Life Summary of Available Data The concentrations below have been rounded to two significant figures. butylbenzyl phthalate Final Fish Acute Value = 66,000 ug/1 Final Invertebrate Acute Value = 170 ug/1 Final Acute Value = 170 ug/1 Final Fish Chronic Value = not available Final Invertebrate Chronic Value = not available Final Plant Value = 170 ug/1 Residue Limited Toxicant Concentration = not available Final Chronic Value = 170 ug/1 •. 0.44 x Final Acute Value = 75 ug/1 diethyl phthalate Final Fish Acute Value = 4,400 ug/1 Final Invertebrate Acute Value = 130 ug/1 Final Acute Value = 130 ug/1 Final Fish Chronic Value = not available Final Invertebrate Chronic Value = not available Final Plant Value = 66,000 ug/1 Residue Limited Toxicant Concentration = not available Final Chronic Value = 66,000 ug/1 0.44 x Final Acute Value = 57 ug/1 dimethyl phthalate Final Fish Acute Value = 8,600 ug/1 Final Invertebrate Acute Value = 1,300 ug/1 B-18 ------- Final Acute Value = 1,300 ug/1 Final Fish Chronic Value = not available Final Invertebrate Chronic Value = not available Final Plant Value = 26,000 ug/1 Residue Limited Toxicant Concentration = not available Final Chronic Value = 26,000 ug/1 0.44 x Final Acute Value - 570 ug/1 No saltwater criterion can be derived for any phthalate ester using the Guidelines because no Final Chronic Value for either fish or invertebrate species or a good substitute for either value is available, and there are insufficient data to estimate a criterion using other procedures. \B-19 ------- Table 8. Marine fish acute values for phthalate esters (U.S. EPA, 1978) ro to o Organism Sheepshead minnow (j uvenilc), Cyprinodon variegatus Sheepshead minnow (juvenile), Cyprinodon variegatus Sheepshead minnow (juvenile), Cyprinodon variegatus Adjusted Bioaseay Test Time LC50 LC50 Method * Cone. ** (hrs) (ug/1) (ug/i) Butylbenzyl phthalate S U 96 445.000 243,282 Diethyl phthalate U 96 29.600 16.182 Dimethyl phthalate U 96 58.000 31,709 * 'S = static ** U = unmeasured Geometric mean of adjusted values: butylbenzyl phthalate « diethyl phthalate - —a dimethyl phthalate = 243.282 —3-7— = 66,000 tJg/1 j— = 4,400 Mg/1 U^. = 8,600 pg/1 ------- Table 9. Marine invertebrate acute values for phthalate esters (U.S. EPA, 1978) Organism Mysid shrimp, Mysidopsis bahia Mysid shrimp, Mysidopsis bahia Mysid shrimp, Mysidopsis bahia bioassay Test Time Method * Cone.** if'is) LC50 (uq/J.) U Piethyl phthalate 96 7,590- Adjusted LCbO Butylbenzyl phthalate U 96 9.630 8,157 6,429 Dimethyl phthalate U 96 73,700 62,424 DO tsj * S = static **U = unmeasured. ft I 5 7 Geometric mean of adjusted values: butylbenzyl phthalate = '^ = 170 yg/1 diethyl phthalate - Ao ~ 13° "8/1 dimethyl phthalate - 64^>2A = 1,300 pg/1 ------- Table 10- Marine plane effects for phthalate esters (U.S. EPA, 1978) 03 I to NJ Organism Alga. Skeleconema costatura Alga, Skeletonema costatum Alga, Skeletonema costatum Alga, Skeletonema costatum Alga, Skeletonema costatum Alga, Skeletonema costatum Etfect chlorophyll a EC50 after 96 hr Cell numbers EC50 after 96 hr Chlorophyll a EC50 after 96~ hr Cell numbers EC50 after 96 hr Chlorophyll a EC50 after 96 hr Cell numbers EC50 after 96 hr Concentration (uq/i) Butylbenzyl phthalate 170 190 Diethyl phthalate 65,500 85.000 Dimethyl phthalate 26.100 29.800 Lowest plant value = butylbenzyl phthalate = 170 Mg/1 diethyl phthalate = 65,500 ug/1 dimethyl phthalate = 26.100 gg/1 ------- to I Table 11, Other marine data for phthalate esters (Laughlin. et al. 1977) Organism Test Duration Effect Result (uq/11 Reference Mud crab (larva), Rhithropanopeus Harrisii Entire larval development Di-n-butyl phthalate None on development 1,000 Laughlin, et al. 1977 Mud crab (larva), Rhithropanopeus harrissii Entire larval development Dimethyl phthalate None on development 1,000 Laughlin, et al. 1977 ------- PHTHALATES REFERENCES Laughlin, R.B., et al. 1977. Effects of polychlorinated biphenyls, polychlorinated napthalenes, and phthalate esters on larval development of the mud crab Rhithropanopeus harrisii. Pages 95-110. Ir\ Pollutant effects on marine organisms. D.C. Health Co., Lexington, Mass. Mayer, F.L. 1976. Residue dynamics of di-2-ethylhexylphtha- late in fathead minnows (Pimephales promelas). Jour. Fish. Res. Board Can. 33: 2610. Mayer, F.L. Jr., and H.O. Sanders. 1973. Toxicology of phthalic acid esters in aquatic organisms. Environ. Health Perspect. 3: 153. Mayer, F.L., et al. 1977. Collagen metabolism in fish exposed to organic chemicals. Pages 31-54. In Recent advances in fish toxicology, a symposium. EPA 600/3-77-085. U.S. Environ. Prot. Agency, Corvallis, Oe. Mehrle, P.M., and F.L. Mayer. 1976. Di-2-ethylhexylphthalate: Residue dynamics and biological effects in rainbow trout and fathead minnows. Pages 519-524. Ir\ Trace substances in environmental health. University of Missouri Press, Columbia. B-24 ------- Sanborn, J.R., et al. 1975. Plasticizers in the environment: The fate of di-N-octyl phthalate (OOP) in two model ecosystems and uptake and metabolism of OOP by aquatic organisms. Arch. Environ. Contam. Toxicol. 3: 244. % Sanders, H.O., et al. 1973. Toxicity, residue dynamics, and reproductive effects of phthalate esters in aquatic invertebrates. Environ. Res. 6: 84. U.S. EPA. 1978. In-depth studies on health and enviromental impacts of selected water pollutants. Contract No. 68-01- 4646. B-25 ------- Mammalian Toxicology and Human Health Effects EXPOSURE Introduction The annual production of phthalic acid esters in the United States in 1977 amounted to approximately 1.2 billion pounds. Table 1 lists the major esters with their production figures. Since 1945, the cumulative total production (up to 1972) of these esters reached a figure of 12.5 billion pounds (Peakall, 1975). On a worldwide scale, 3 to 4 billion pounds are produced annually. When the term "phthalate esters" is used, it indicates the ortho form of benzenedicarboxylic acid. Two other iso- meric forms of benzenedicarboxylic acid esters are also pro- duced. These include the meta form (or isothalate esters) and the para form (or terephthalate esters). Both of these isomers have a number of important commercial applications such as starting materials for plastics and textiles. In this document, however, consideration will be given only to the "ortho" esters. The phthalate esters can be prepared by reaction of phthalic acid with a specific alcohol to form the desired esters. In industry, however, the esters are manufactured from phthalic anhydride rather than from the acid. For the most part, manufactured esters will not be completely pure, having various isomers and contaminates present. These esters, however, can be prepared with a purity of greater than 99 percent even though most of these esters are not sold with this high degree of purity. ------- TABLE 1 Production of Individual Phthalic Acid Esters in U.S. in 1977 Ester Production in Pounds (1000 pounds) Dibutyl 16,592 Diethyl 17,471 Diisodecyl 160,567 Dimethyl 9,887 Dioctyl Di-2-ethylhexyl 388,543 Other dioctyl phthalates 11,664 Di-tridecyl 23,278 n-Hexyl n-decyl 15,182 All other phthalate esters 559,229 Total 1,202,413 From:United States International Trade Commission, U.S. Government Printing Office, Washington, 1978, USITC Publication 920, p. 263. Pthalic acid esters have a large number of commercial uses, the largest being as plasticizers for specific plas- tics such as polyvinyl chloride. Other uses for these esters include: defoaming agents in the production of paper, in cos- metic products as a vehicle (primarily diethyl phthalate) for perfumes, in lubricating oils, and in other industrial and consumer applications. Table 2 illustrates the variety of uses for esters with an estimate of the amount of the esters c-2 ------- TABLE 2 Uses of Phthalate Esters in the United States A. As Plasticizers Building and Construction Wire and cable 185 Flooring 150 Swimming pool liners 20 Miscellaneous 32 Subtotal Hf7 Home Furnishings Furniture upholstery 90 Wall coverings 38 Houseware . 30 Miscellaneous 45 Subtotal 203 Cars (upholstery, tops, etc.) 114 Wearing apparel 72 Food wrapping and closures 25 Medical tubing and intravenous bags 21 Total as Plasticizers ... 922 B. As Nonplasticizers Pesticide Carriers — Oils Insect repellent — Total as Nonplasticizers 50 Grand Total 972 From:Graham,1973. C-3 ------- used in the specific categories. Approximately 20 different esters are used in the specific categories. Dioctyl phthalate (includes di-2-ethylhexyl phthalate and other dioctyl phthalates) accounts for approximately 42 percent of the esters produced in this country, followed by diisodecyl phthalate. Dioctyl phthalate (DOP) and di-2- ethylhexyl phthalate (DEHP) are often used synonymously even though it should be clear that they are not the same, one being the isomer of the other. For the most part, the esters are colorless liquids, have low volatility, and are poorly soluble in water but soluble in organic solvents and oils. Table 3 lists several of the physical properties of these esters. Evidence also is available suggesting that certain plants and animal tissue may synthesize phthalic acid esters (Peakall, 1975). However, to what extent this occurs in nature is not known. The extremely large production of phthalates and the variety of uses for these esters have led to the presence of these esters in water sources, food, consumer products, air (industrial settings, automobiles having vinyl furnishings), and in medical devices such as tubings and blood bags. Esters can thus enter the environment and biological species, including man, through a variety of sources. Therefore, man is exposed to phthalates from a variety of routes such as: (1) ingestion from water, (2) ingestion from food, (3) inhalation, (4) dermal and (5) through paren- teral administration (via blood bags and tubes in which the ester is extracted by a parenteral solution including blood). C-4 ------- TABLE 3 Physical and Chemical Properties of Phthalate Esters Compound Molecular .Weight Dimethyl phthalate Diethyl phthalate Diallyl phthalate Diisobutyl phthalate Dibutyl phthalate Dimethoxy ethyl phthalate Dicyclohexyl phthalate Butyl octyl phthalate Dihexyl phthalate Butj-lphthalyl butyl glycolate Dibutoxyethyl ethyl phthalate Di-2-ethylhexyl phthalate Diisooctyl phthalate Di-r.-octyl phthalate Dincnyl phthalate 194.18 222.23 246.27 278.3 278.34 282.0 330.0 334.0 334.0 336.37 366.0 391.0 391.0 391.0 419.0 Specific Bp, Gravity °C 1.189 (25/25) 282 1.123 (25/4) 296.1 1.120 (20/20) 290 1.040 327 1.0465 (21) 340 1.171 (20) 190-210 1.20 (25/25) 220-228 340 0.990 1.097 (25/25) 219/5 nun/ 1.063 210 0.985 (20/20) 386.9/5 mm 0.981 239/5 mm 0.978 220/5 mm/ 0.965 413 Solubility in H20, g/100 ml 0.5 Insoluble 0.01 Insoluble 0.45 (25°C) 0.85 Insoluble — Insoluble 0.012% 0.03 Insoluble Insoluble Insoluble Insoluble C-5 U • ------- Ingestion from Water In the early seventies, a great deal of attention began to focus on chemical contaminants in surface water and adja- cent ocean regions. One of the first reports published on the presence of phthalic acid esters was presented by Corcoran (1973). He indicated that a level of approximately 0.6 ppm DEHP was present at the mouth of the Mississippi River. He further calculated that approximately 350 million pounds of the ester enter the Gulf of Mexico from the Mississippi River each year. As pointed out by Peakall (1975), the 350 million pounds stated by Corcoran must be in error and may be due to an error in the analytical procedure or to an abnormal local concentration. Corcoran also indicated the presence of DEHP (or its equivalent in the Gulf near Pensacola, Florida and in the clear blue waters of the Gulf Stream, but the levels of the esters were much less than at the mouth of the Mississippi. Hites (1973) studied chemical contaminants in the Charles and Merrimack Rivers in Massachusetts. He reported that ap- proximately seven miles from the mouth of the Charles River the level of phthalate was 1.8 to 1.9 ppb. As the water ap- proached the mouth of the river, the level was reduced. For example, three miles from the mouth, the level was 1.1 ppb while at one mile from the mouth, the level ranged from 0.88 to 0.98 ppb. A review of various EPA reports shows that surface waters do contain phthalate esters in parts per billion, with the levels being higher at sites close to industrial centers. C-6 ------- Ingestion from Food Since a number of packaging materials and tubings used in the production of foods and beverages are polyvinyl chloride containing phthalic acid esters, primarily DEHP, the esters can migrate to the food and beverages. The extent of migra- tion depends upon a number of factors such as temperature, surface area contact, lipoidal nature of the food and length of contact. Peakall (1975) refers to reports on the migration of plasticizers from tubings used in milk production. Extrac- tion levels for the dinonyl phthalate ester (in PVC tubing) were found to be 4.6 mg/100 ml/day at 38°C and 7.0 mg/100 ml/day at 56°C. The rate for DEHP was 2.0 mg/100 ml/day at 38°C and 3.1 mg/100 ml/day at 56°C. The tubing was 1 meter in length and 100 ml of milk was the extracting medium. Peakall suggests that approximately 40 mg of DEHP could be extracted over a 15-day period from tubings in contact with milk in actual practice but went on to indicate the actual levels in milk are not known. A German report (Pfab, 1967) indicates that cheese and lard placed experimentally in contact with two plastic films (one containing dibutyl and the other dicyclo- hexyl phthalates) extracted less than one percent of the esters after one month at 25°C. The concentrations in the food were reported as less than 2 ppm. Food and Drug Administration surveys indicate that sev- eral of the phthalate esters are present in food and fish which have had contact with plastic packaging systems such as polyvinyl chloride (PVC). Some data on the residue of the esters in Japanese foods have also been reported. Table 4, C-7 ------- also been reported. Table 4, taken from the study by Tomita, et al. (1977) shows the amounts of several agents migrating to selected Japanese foods packaged in plastics, laminated films, paper, and aluminum foil. As will be noted, levels above 600 ppm and even higher than 3000 ppm of total phthalates migrated to certain foods. A bioconcentration factor (BCF) relates the concentration of a chemical in water to the concentration in aquatic organ- isms, but BCF's are not available for the edible portions of all four major groups of aquatic organisms consumed in the United States. Since data indicate that the BCF for lipid- soluble compounds is proportional to percent lipids, BCF's can be adjusted to edible portions using data on percent lipids and the amounts of various species consumed by Americans. A recent survey on fish and shellfish consumption in the United States (Cordle, et al. 1978) found that the per capita con- sumption is 18.7 g/day. From the data on the nineteen major species identified in the survey and data on the fat content of the edible portion of these species (Sidwell, et al. 1974), the relative consumption of the four major groups and the weighted average percent lipids for each group can be calcu- lated: Consumption Weighted Average Group (Percent) Percent Lipids Freshwater fishes 12 4.8 Saltwater fishes 61 2.3 Saltwater molluscs 9 1.2 Saltwater decapods 18 1.2 C-8 ------- Using the percentages for consumption and lipids for each of these groups, the weighted average percent lipids is 2.3 for consumed fish and shellfish. Measured steady-state bioconcentration factors of 57, 117, and 663 were obtained for dimethyl, diethyl, and butyl- benzyl phthalates using bluegills containing about one percent lipids (U.S. EPA, 1978). An adjustment factor of 2.3/1.0 = 2.3 can be used to adjust the measured BCF from the 1.0 per- cent lipids of the bluegill to the 2.3 percent lipids that is the weighted average for consumed fish and shellfish. Thus the weighted average bioconcentration factors for dimethyl, diethyl, and butylbenzyl phthalates and the edible portion of all aquatic organisms consumed by Americans are calculated to be 130, 270, and 1,500, respectively. No measured steady-state bioconcentration factor (BCF) is available for dibutyl phthalate, but the equation "Log BCF = 0.76 Log P - 0.23" can be used (Vieth, et al. Manuscript) to estimate the BCF for aquatic organisms that contain about eight percent lipids from the octanol-water partition coeffi- cient (P). Based on an octanol-water partition coefficent of 760, the steady-state bioconcentration factor for dibutyl phthalate is estimated to be 91. An adjustment factor of 2.3/8.0 = 0.2875 can be used to adjust the estimated BCF from the 8.0 percent lipids on which the equation is based to the 2.3 percent lipids that is the weighted average for consumed fish and shellfish. Thus, the weighted average bioconcentra- tion factor for dibutyl phthalate and the edible portion of all aquatic organisms consumed by Americans is calculated to be 91 x 0.2875 = 26. C-9 ------- An average measured steady-state bioconcentration factor of 330 was obtained for di-2-ethylhexyl phthalate using fat- head minnows containing about eight percent lipids (Mayer, 1976). An adjustment factor of 2.3/8.0 = 0.2875 can be used to adjust the measured BCF from the 8.0 percent lipids of the fathead minnow to the 2.3 percent lipids that is the weighted average for consumed fish and shellfish. Thus, the weighted average bioconcentration factor for di-2-ethylhexyl phthalate and the edible portion of all aquatic organisms consumed by Americans is calculated to be 330 x 0.2875 = 95. Inhalation This route may be a significant portal of entrance for esters of phthalic acid, at least to selected populations at risk. The presence of the esters in air for relatively short periods of time most likely is due to the incineration of PVC items. In closed spaces such as automobiles having PVC fur- nishings, the ester can volatilize and the persons inside the vehicle will inhale the vapors. In closed rooms which have PVC tiles, levels of esters may reach 0.15 to 0.26 mg/m3 (Peakall, 1975). Mens'shikova (1971) reported the presence of dibutyl phthalate from ship quarters furnished with PVC tile, decorative laminated plas- tics and pavinols (assumed to be PVC plastics). He reported that even after three years, the level of DBP in the air of the rooms contained from 0 to 1.22 mg/m3 of the ester. Milkov, et al. (1973) reported that vapors or aerosols of phthalate esters ranged from 1.7 to 40 mg/m3 at one working site where mixing was done and a level of 10 to 66 mg/m3 at C-10 ------- o TABLE 4 Migration of Phthalic Acid Esters from Packaging Film to Foodstuffs* Time after manufacture Foodstuffs (months) Tempura (frying) A powder B Instant cream A soup B C Instant soybean soup Soft margarine Fried potato A cake B C Orange juice Red ginger pickles Sugar Table salt 1 1 ....... .,.., , — , 3 4 14 p 4 1 1 ? p p Packaging materials (ppm) Materials** Pl-L Pl-L P-A1-P1 P-Al-Pl P-A1-P1 P-Pl Pi P-PL P-PL P-PL P-Pl PI Pi P-Pl DNBP 70.28 6.29 23.17 586.16 588.75 2.75 1.29 10.86 10.66 22.98 1.52 3.00 7.24 5.18 DEHP 3675.0 2.30 1.35 58.92 58.93 1.85 1.44 385.85 1.28 11.80 0.74 2.14 2.75 2.58 Total 3745.28 8.59 24.52 647.08 647.08 4.60 2.73 396.91 11.94 34.78 2.26 5.14 9.99 7.76 Foodstuffs (ppm) DNBP 14.70 0.39 1.73 60.37 51.79 nd nd 1.11 nd 1.21 0.35 0.11 nd nd DEHP 68.08 0.11 0.04 2.15 3.01 nd nd 0.05 nd 9.06 0.05 nd nd nd Total 82.78 0.50 1.77 62.52 54.80 nd nd 1.16 nd 10.27 0.40 0.11 nd nd From: Tomita, et al. 1977. ** Pi indicates plastic L indicates laminated film P indicates paper Al indicates aluminum foil ------- another working site in a company manufacturing artificial leather and films of PVC. American published reports regarding levels of esters in the working environment are rare. Thus insufficient data are available to judge what levels of these esters are present in various working sites manufacturing the esters or using the esters for consumer products. It seems reasonable to assume that certain workers will be exposed to the phthalic acid esters in the form of the vapor or as mists. Depending upon the hygiene standard main- tained, these workers could inhale sufficient concentrations of the ester to lead to health problems. Dermal The phthalate esters can be absorbed through the skin and this route may thus become an important portal of entrance. Many cosmetic products may contain small concentrations of the lower molecular weight phthalate esters such as diethyl phthalate, and thus application to the skin could introduce the ester to humans through the skin. Since dimethyl phthal- ate is used as a mosquito repellent, dermal absorption can occur. Swimmiig pools lined with PVC could also release the phthalate esters to the water and, in turn, swimmers would be exposed to very minute concentrations of the plasticizer (phthalate esters) which could then be absorbed through the skin. As with the other routes, lack of available data pre- vents even a very crude projection of the levels of esters which could enter man through the skin. Since a number of medical devices such as blood bags, in- fusion containers, collection and administration tubings, and C-12 ------- catheters are prepared from plasticized (generally DEHP) poly- vinyl chloride, a parenteral route of entrance into a selected human population becomes a possibility. In fact, it is pos- sible that the parenteral route contributes the greatest quan- tity of the esters to selected groups under medical care in hospitals. These medical devices have been introduced into medical practice since Walter (1951) first introduced the polyvinyl chloride blood bag in 1950, and thus, many millions of persons have been exposed to phthalate esters by the parenteral route. The total number of renal hemodialyses performed each year in the United States has reached close to six million. A single five hour dialysis will expose these patients to ap- proximately 150 mg of DEHP. In open heart surgery, extra cor- poreal pump oxygenators are used. Approximately 360,000 such operations are performed each year. Under these conditions, a patient may be exposed to an average of 33 mg of DEHP during the surgery. As early as 1960, a report appeared by Meyler, et al. (1960) that certain medically used PVC tubings released toxic ingredients to solutions passed through them. Isolated heart experiments were used to detect toxic ingredients released from PVC. Since these specific "toxic" tubings contained an organotin stabilizer, the authors surmised that the toxic com- ponent was the stabilizer and not the phthalate ester. Braun and Kummel (1963), reported that PVC containers used for storage of blood and transfusion solutions did re- lease phthalate esters as well as other additives to an ex- tracting medium (water). C-13 ------- A report by Guess, et al. (1967) revealed that a number of American PVC blood bags containing an anticoagulant solu- tion (ACD) were contaminated by the presence of small amounts of DEHP, 2-ethylhexanol, phthalic anhydride, phthalic acid and some unidentified chemicals. Jaeger and Rubin (1970) reported the release of phthalate esters from PVC blood bags and tubings and further identified these plasticizers in tissues and organs of two deceased patients who previously were transfused with blood from PVC blood bags. Hillman, et ai. (1975) identified the presence of DEHP in neonatal tissues after the insertion of umbilical catheters. It was interesting to note that three infants who died of necrotizing enterocolitis had significantly higher DEHP values in the gut than infants not having this disorder. There was generally an increase in DEHP content of tissue if the speci- fic patient had also received blood products. Residue levels were measured in both heart and gastrointestinal tissues. The average level of DEHP in heart tissue was 1.27 ug/g» In the gut of the three patients having died of gastrointestinal dis- orders, the levels ranged from 0.016 to 0.63 ug/g. It is now well recognized that plasticized PVC medical devices will release the plasticizers to tissue and to solu- tions in contact with the object. Extraction of a plasticizer such as DEHP with water is extremely small with the present PVC blood bags and infusion containers, but if lipoidal solu- tions such as blood and blood fractions are used, the extent of release becomes significant. The quantity of di-2-ethylhexyl phthalate released into C-14 ------- stored blood at 4°C for 21 days ranges from 5 to 7 mg/100 ml (Jaeger and Rubin, 1972). Kevy, et al. (1978) have done extensive studies on DEHP and found the plasticizer to be extracted from PVC storage containers into blood and blood components. A summary of some of their extract results is shown in Table 5. Needham and Luzzi (1973) indicated that when PVC infu- sion containers containing normal saline were agitated/ DEHP would occur in colloidal form in the saline. Even under this condition, however, the total concentration of the colloidal particles came to 0.1 ppm (Darby and Ausman, 1974). The pres- ence of ethyl alcohol in the solution will increase the level of DEHP in the solution. A ten percent solution will in- crease the DEHP content to 6 ppm while a concentration of 40 percent will increase the DEHP in the solution to 30 ppm (Corley, et al. 1977). TABLE 5 Extraction Data of DEHP from PVC Containers 1. Normal whole blood stored at 4°C contains 0.19 mg% DEHP on collection and 5.84 mg% after 21 days of storage. 2. Cryoprecipitate which is prepared and stored at -30°C contains low levels of DEHP (1.05 to 2.6 mg%). 3. The level of DEHP in stored platelets maintained at 4°C 22°C after 72 hours is 10.85 mg% and 43.21 mg%, respec- tively. Summarized from: Kevy, et al. 1978. The total quantity of DEHP a transfused patient may re- ceive parenterally will, of course, depend upon the number of units of blood or blood products administered to him. Pa- tients undergoing chronic transfusions with whole blood, C-15 ------- packed cells, platelets and plasma stored in PVC containers may receive a total of approximately 70 mg of DEHP. There are cases, however, when a patient may receive as many as 63 units of blood containing approximately 600 mg of DEHP (Jaeger and Rubin, 1972). PHARMACOKINETICS Absorption The phthalic acid esters and/or their metabolites are readily absorbed from the intestinal tract, the intraperi- toneal cavity, and the lungs. There is also evidence in- dicating that these esters can be absorbed through the skin. As will be pointed out, the vehicle can play an important role in the absorption, distribution, and elimination of the ester. Schulz and Rubin (1973) administered orally to rats l^c-DEHP in corn oil and found that approximately 13 percent of the administered dose was found in the organic solvent extracts of urine, feces, and contents of the large intes- tine. The urine contained about 62 percent in water ex- tracts. Daniel and Bratt (1974) injected a single oral dose of 14C-DEHP in rats and found 42 percent and 57 percent of the dose in the urine and feces, respectively, in seven days. They also pointed out that a significant amount of the dose is excreted in bile. In studies by Wallin, et al. (1974) rats were orally administered ring or side chain- labeled DEHP. Twenty-four hours after the dose was given, approximately 50 percent of the recovered radioactivity was found in the feces and in the gastrointestinal tract contents. C-16 ------- The remaining radioactive substance was recovered in the urine. The authors also indicated that "a portion of the radioactivity recovered from the feces undoubtedly had been absorbed but returned to the gut in the bile." Lake, et al. (1975) have suggested that orally admin- istered phthalic add esters are absorbed in the gut pri- marily as monoesters. Wallen, et al. (1974) however, found from their studies that a significant amount of orally admin- istered DEHP is absorbed in the gastrointestinal tract as the intact compound. From the present data, it appears clear that the diester phthalates can be hydrolyzed to the mono- ester in the gut and thus be absorbed as the monoester. Further studies are needed to clarify the ratio of intact diester to monoester which would be absorbed in the gut under various conditions in several species of animals. Information on the absorption of the phthalic acid es- ters in man is limited. As early as 1945, however, Shaffer, et al. (1945) reported that a single oral dose of 10 g DEHP in a human subject was recovered as a phthalate equivalent in the urine after 24 hours. The amount recovered was 4.5 per- cent of the original dose. In another subject, 5 g of DEHP was taken orally and 2.0 percent of the original dose (as phthalate equivalent) found in the urine 24 hours later. Tomita, et al. (1977) reported the presence of phthalate es- ters in the blood of individuals having ingested food which had been in contact with flexible plastics having the phthalic acid esters. DEHP and di-n-butyl phthalate (DNBP) C-17 ^ / ------- levels detected in the blood after meals were much higher than prior to eating the foods in the plastic packaging system. In 13 individuals who were included in the study, (DEHP and DNBP) in blood ranged from 0.13 to 0.35 ppm when compared to an average value of 0.02 ppm prior to the meals. Dillingham and Pesh-Imam detected nine percent in urine 24 hours after labeled DEHP had been applied to rabbit skin. After 48 hours, the levels in the urine had increased to 14 percent and within 72 hours the radioactivity had increased to 16 to 20 percent of the originally administered dose. Distribution Absorbed asters of phthalic acid esters (or their metab olites) distribute quite rapidly to various organs and tis- sues both in animals and humans. Again, it must be kept in mind that, depending upon the route and the physical form of the ester (true solution, colloid, emulsion), the distribu- tion of the esters (metabolites) can vary. Jaeger and Rubin (1970) studied the distribution of DEHP in human tissues of two deceased patients having had large volumes of blood (stored in PVC blood bags) transfused into them. They de- tected the presence of DEHP in spleen, liver, lung, and ab- dominal fat with concentrations ranging from 0.025 mg/g in spleen to 0.270 mg/g in abdominal fat. Radio-labeled DEHP (emulsified in oleic acid) admin- istered i.v. as a single dose was found to disappear rapidly from blood and approximately 60 to 70 percent of the total dose was detected in the liver and lungs within two hours of 018 ------- administration of the dose (Daniel and Bratt, 1974). In studies in which rats were maintained on diets containing DEHP, there was a progressive increase in the amount of the compound in the liver and abdominal fat of the animals but within a short time a steady state concentration was achieved (Daniel and Bratt, 1974). Waddell, et al. (1977) examined the distribution of 14C- DEHP (serum solubilized) after a single i.v. injection in rats using whole body autoradiography techniques. Results from the study revealed that a rapid accumulation of radio- activity in the kidney and the liver had occurred followed by rapid excretion into urine, bile, and intestine. No accumu- lation of the compound was found (up to 168 hours after the injection) in the spleen and lung, but significant radio- activity was detected in the lumen of the intestine which the authors surmised occurred because of the secretion of the compound by the liver into the bile. Tanaka, et al. (1975) administered 14C-DEHP solubilized in Tween 80 orally to groups of rats. The concentrations in the liver and kidney reached a maximum level in the first two to six hours. Peak blood levels of the compound occurred about six hours after administration. Intravenous adminis- tration of labeled DEHP as a dispersion prepared by sonifica- tion of DEHP in saline led to 70 to 80 percent of the origi- nal dose deposited in the liver after the first hour. After two hours, the radioactivity had declined to 50 percent and only 0.17 percent radioactivity was found in the liver at the C-19 ------- end of the seventh day. The intestine (after oral and i.v. administration) revealed a relatively high level of radio- activity but not to the same extent as the liver. On the other hand, the testicles and brain appeared to have little affinity for the compound regardless of the route of adminis- tration. Other organs and tissues also showed low levels of radioactivity after 24 hours of oral dosing. Dillingham and Pesh-Imam injected i.v. a single dose of labeled DEHP in mice and found that after seven days the highest specific activity resided in the lungs, with lesser amounts in the brain, fat, heart, and blood (Autian, 1973). These investigators did not find preferential deposition of DEHP (as radioactivity) in fatty tissue. Application of labeled diethyl phthalate to the skin of rabbits resulted in detection of the compound in the lung, heart, liver, kidney, gonads and spleen after three days. The compound (or its metabolite) was also detected in the brain but, surprisingly, no radioactivity was detected on the skin or subdermal fatty tissue at the site of application. With the current information on distribution of the phthalate esters, it can be concluded that the esters are rapidly distributed to various organs and tissues with no ap- parent accumulation. Yet it is now well-recognized that the general population and patients having received large-volume blood or blood products may have residues of phthalate esters or metabolites in tissues and organs. A study by Jacobson, et al. (1977), in which nonhuman primates were transfused with blood containing DEHP following a procedure of treatment C-20 ------- common to humans revealed the presence of DEHP (or metabo- lites) in trace amounts even up to 14 months post-transfu- sion. As pointed out by Daniel and Bratt, (1974), there probably is a steady state concentration which is reached after which the esters (or metabolites) are then rapidly eliminated from the organs or tissues through various routes, thus preventing significant accumulation over long periods of exposure. Metabolism Albro, et al. (1973) have identified the metabolites of DEHP after oral feeding to rats. These authors conclude that the first step in the metabolism is the conversion of the diester to monoester (mono-2-ethylhexyl phthalate). By {jj- and (OJ-1) oxidation, the side chain of the monoester forms two different alcohol intermediates. Further oxidation of the alcohols leads to the corresponding carboxylic acid or ketone and, in turn, the acid may be further oxidized (^-oxi- dation) . Figure 1 shows a number of products which can be formed from metabolism of orally ingested DEHP (in rats). Lack of detailed data on the metabolism of other esters in various species of animals and in humans prevents a clear understanding of what metabolic products are formed in other species. It seems clear, however, that for DEHP a signifi- cant biotransf ormation can take place in the gut (DEHP to the monoester) and thus the same possibility may also be true in other higher orders of animals and in man. The absorbed intact DEHP and/or the monoester is then further metabolized in the liver. C-21 ------- o 10 to DEHP 0 ,—C—OH C—0—CH,—CH—(CH,),—CH, CH, CH, Monocthylhcxyl phtholntc O ,— C— OH OH C—O—CH,—CH—CH,—CH,—C—CHa CH,^ II CH, O C—0—CH,—CH—CH,—CH,—C—CH, O CH, CH, 0 ,—C—OH O C—0—CH,—CH—(CH,),—C—OH in,, CH, 0 >C-OH ^^—C— 0— CH,—CH— CH,—C— OH CH, CH, Figure 1. Routes of metabolism of. di(2-ethylhexyl) phthalate (after Albro, et al. 1973) ------- Excretion For the most part, the esters of phthalic acid in ani- mals and man are excreted readily in urine and feces. For example, Lake, et al. (1975) found that a single oral dose of labeled DEEP was practically all excreted in urine and feces within a four day period, leaving less than 0.1 percent of the radioactivity in the organs and tissues. Rats pretreated with DEHP for 6 and 13 days also showed a similar elimination rate upon the administration of labeled DEHP. Excretion into bile also appears to be a significant route of excretion in- creasing the content of DEHP (or metabolites) in the intes- tine. Schulz and Rubin (1973-) administered labeled DEHP i.v. to groups of rats and then monitored the radioactivity in blood versus time. They noted a bi-phasic curve when the data were plotted as log DEHP vs time. The initial slope led to a half-life in blood of nine minutes while the second slope gave a half-life of 22 minutes. Within one hour, eight percent of the total injected DEHP was found in water-soluble metabolites, primarily in the liver, intestinal contents and urine. Twenty-four hours after injection, 54.6 percent of the initial dose was recovered as water-soluble metabolites primarily in the intestinal tract, excreted feces, and urine and only 20.5 percent was recovered in organic extractable form. Dillingham and Pesh-Imam studied the excretion in the urine of mice of labeled DEHP administered i.p. (as pure ester) and i.v. (as saturated saline solution), (Autian, 1973). C-23 ------- They noted that 68 percent and 63 percent, respectively, of the total initial dose was excreted in seven days. Tanaka, et al. (1975) reported about 80 percent of the original labeled DEHP given orally or by i.v. to rats was excreted in the urine and feces in five to seven days. These authors also pointed out that, upon a single oral administra- tion of DEHP, the intact diester could not be identified in the urine. On the other hand, repeated oral administration of 500 mg/kg in rats for 20 days revealed the presence of in- tact DEHP in the urine. They concluded that "repeated admin- istration of DEHP may lead to its accumulation in the body until a steady state is reached between the rates of absorp- tion and elimination." After steady state is reached, DEHP, as the unchanged molecule, would appear in the urine. As Thomas, et al. (1978) have expressed in their review article on biological effects of DEHP, pharmacokinetic data in animals and humans support the thesis that DEHP is ab- sorbed from the gastrointestinal tract and widely distributed to various tissues following either the oral or i.v. routes of administration. DEHP is then rapidly metabolized to a number of derivatives of mono-2-ethylhexyl phthalate which are, in turn, excreted mainly in the urine. The half-life of elimination from tissues and the body is short. EFFECTS Acute, Sub-acute, and Chronic Toxicity One of the first comprehensive reviews on the toxicity of phthalate esters was presented by Autian in 1973. A much more detailed review of the phthalate esters was given by C-24 / 1 ------- Peakall in 1975 and the most recent one on this subject was published by Thomas, et al. in 1978. The potential health threats of phthalic acid esters in the early seventies led to a national conference on the subject in 1972. The papers presented at this meeting were published in the January 1973 issue of Environmental Health Perspectives. As will become evident, most of the detailed toxicological studies have centered primarily on DEHP since this specific ester accounts for approximately 40 percent of the phthalates which are used commercially. From the accumulated data on acute toxicity in animals, the phthalate esters may be considered as having a rather low order of toxicity. It is now thought that the toxic ef- fect of the esters is most likely due to one of the metabo- lites in particular to the monoester. This appears to be the case for DEHP since this ester has been studied more exten- sively than the others. Table 6 is taken from Autian's 1973 review and lists the 1,050 is of the esters. Oral acute tox- icity for the lower molecular weight esters is greater in animals than for the higher molecular weight esters such as DEHP. Other routes of administration such as i.p. and dermal do not significantly increase the acute toxicity. The toxicity of DEHP by the i.v. route is quite impor- tant since, as has been indicated previously, PVC administra- tion devices will leach the plasticizer into blood and lipo- protein-containing solutions. Since DEHP has a very limited solubility in water, other means of administering the agent C-25 ------- TABLE 6 Acute Toxicity of Phthalate Esters: LD5Q in Animals (Autian, 1973). Compound Dimethyl phthalate Diethyl phthalate Dime thoxy ethyl phthalate Diallyl phthalate Dibutyl phthalate Diisobutyl phthalate Butyl carbobutoxy- methyl phthalate Dihexyl phthalate Animal Mouse Mouse Mouse Rat Rat Guinea pig Rabbit Mouse Mouse Rat Rabbit Mouse Mouse Rat Rat Guinea pig Guinea pig Mouse Rat Rabbit Rabbit Mouse Rat Rat Rabbit Mouse Mouse Rat Guinea pig Rat Rat Rat Rabbit Route Oral IP IP Oral IP Oral Dermal IP IP IP Oral Oral IP Oral IP Oral Dermal IP Oral Oral Dermal IP IP IM Dermal Oral IP IP Dermal Oral IP Oral Dermal LD50 g/Kg 7.2 3.6 1.58 2.4 3.38a 2.4 10. Oa 2.8 2.8 5.06a 1.0 3.2-6.4 2.51 4.4 3.7 1.6-3.2 10. Oa 0.7 1.7 1.7 3.4a 4.0 3.05a 8.0 20. Oa 12.8 4.50 3.75a 10. Oa 14. 6a 6.89 30.0 20. Oa C-26 ------- TABLE 6 (Continued) Compound Dioctyl phthalate Di-2-ethyhexyl phthalate Animal Mouse Rat Guinea pig Mouse . Rat Rat Rabbit Guinea pig Route Oral IP Dermal IP Oral IP Oral Dermal LD50 g/Kg 13.0 50. Oa 5.0a 14.2 26.0 50. Oa 34.0 10.0 Butylbenzyl phthalate Dicapryl phthalate Mouse Mouse IP IP 3.16 14.2 Dinonyl phthalate Dibutyl (diethylene gylcol bisphthalate) Dialkyl phthalate Rat Mouse Mouse Rat Rat Mouse Rat Oral Oral IP Oral IP Oral IP 2.00 11.2 11." 2 ^11.2 >20.00 >20.00 in ml/kg. C-27 ------- in experimental animals have been used to study the toxic ef- fects when administered i.v. Preparation of emulsions or dispersion of DEHP in various vehicles may induce toxic re- sponses when injected i.v. which may not occur when DEHP is solubilized by having the ester migrate from PVC into blood. Studies by Stern, et al. (1977) have indicated that the phar- macokinetic pattern for DEHP will be different depending upon the vehicle which is used and they make the suggestion that i.v. studies should'be performed on the extracted DEHP which will take place when the blood product is placed in contact with a PVC device. Since DEHP will have a limited solubility in blood and blood products/ the total dose given to animals will be relatively small and, in general, no acute toxicity would be expected. Rubin (1976), however, has suggested the possibility of "shocked lungs" when DEHP is administered i*v. and has presented experimental evidence in rats to support this contention. This is discussed in a subsequent section of this report. The low volatility of most of the esters precludes them from presenting an acute toxic response by inhalation. Gen- erally, at least for the higher molecular weight phthalic acid esters, only through heating will there be sufficient vapor concentration to carry out an adequate inhalation study. Even though the phthalate esters have been in commercial production for nearly 50 years, relatively few long-term tox- icity studies appear in the literature. As vould be ex- pected, subacute (or subchronic) studies are more plentiful C-28 / ------- but even these are few when one considers the large produc- tion of these agents every year. Perhaps the meager toxico- logical data can be attributed to the long use of these es- ters with relatively few episodes of ill effects among the general population. Also, it is possible that a number of these esters have been studied in more toxicological detail by industry without the results appearing in published form. A general indication of long-term toxicity of phthalate es- ters can be seen in Table 7 in which Krauskopf (1973) has summarized the maximum no-effect dose for several esters. Dimethyl Phthalate: Dimethyl phthalate is used as an effective mosquito repellent. In human experience, few toxic effects from this ester have been noted. Two-year feeding studies in female rats by Draize, et al. (1948) at levels of two and eight percent in the diet produced only a minor growth effect at the four and eight percent levels. At the eight percent level, some indication of nephritic involvement was detected. Dose levels less than eight percent showed no such effect. A 90-day study in which the ester was applied to the skin of rabbits led to an LD$Q of greater than 4 ml/kg. The ester does not produce primary irritation on the skin nor has it been found to act as a sensitizing agent. Diethyl Phthalate: This ester has been used as a plas- ticizer for cellulose materials and as a perfume carrier. Nearly 50 years ago, Smith (1924) reported that rats could tolerate up to 0.5 percent of their body weight of this ester C-29 ------- TABLE 7 Calculated Allowable Daily Intake (ADI) for Various Phthalate Esters (Krauskopf, 1973) Maximum Period No-Effect Level Ester Species Days (mg/kg/day) Di-2-ethylhexyl Rat 365 400 Rat 730 80 Dog 98 100 Rat 90 200 Dog 98 100 Rat 365 >60>200 Guinea pig 365 60 Dog 365 60 Dibutyl Rat 365 350-110 Rat 450 4.3 Diisonyl Rat 91 150 Dog 91 37 Heptyl nonyl Rat 90 60 Mouse 90 60 C-30 ------- without death occurring. Rabbits could be fed 3 ml/kg/day without significant toxic response (Blickensdorfer and Templeton, 1930). Diethyl phthalate does not act as a pri- mary irritant when applied to the skin nor has it induced al- lergic responses in humans who have contact with it. Heated vapors may produce slight irritancy in mucous membranes of the nasal passages and may also irritate the upper respira- tory tract. Even though diethyl phthalate is not generally used as a plasticizer in PVC tubings, Neergaard, et al. reported that this ester was present in tubings used in hemodialysis equip- ment and that the use of these tubings led to hepatitis in several patients. When other tubings, presumably without di- ethyl phthalate, were used the hepatitis did not occur. It seems unlikely that the ester was responsible for the hepati- tis and the cause may have been related to another additive in the tubing, Dibutyl Phthalate: Smith (1953) studied the effects of feeding dibutyl phthalate to groups of rats. At concentra- tions of 0.01, 0.05, and 0.25 percent of dibutyl phthalate in food, no adverse effects were noted after one year. When the dose level was increased to 1.25 percent, approximately half of the animals died in the first week but the remaining ani- mals grew normally as compared to the untreated controls. Spasovski (1964) conducted a subacute inhalation study lasting 93 days during which mice were exposed for six hours a day to different concentrations of the ester. The concen- trations ranged from 0.017 to 0.42 mg/1. Unfortunately, dur- ing the study, the same animals received various exposure C-31 ------- concentrations rather than specific concentrations for the whole time period and thus interpretation of the results is difficult even though Spasovski proposed a permissible stan- dard concentration (PSC) of 1 mg/m3. Dvoskin, et al. (1961) exposed groups of rats to 0.2 and 0.4 mg/m3 for 2.5 months. Some weight loss was noted and an increase of gamma globulin was reported for the animals receiving the higher dose during the fourth and sixth weeks of the experiments. The same group of animals also demon- strated alterations in the phagocytic activity of neutrophils after one month; these returned to normal. It is difficult to conclude from this study the significance of the results in regard to the toxic potential of dibutyl phthalate when inhaled. A much more detailed study on the inhalation of dibutyl phthalate has been reported by Men'shikova (1971). Rats were exposed continuously for 93 days at chamber concentrations of 0.098, 0.256 and 0.98 mg/m3. No behavioral changes vere noted nor any weight loss discerned. The important finding was that gamma globulin was increased and appeared to be dose related. In.humans, Men'shikova (1971) found an olfactory threshold value ranging from 0.26 to 1.47 mg/m3. Concen- trations of 0.12 and 0.15 mg/m3 resulted in electrocortical conditioned reflex in the three subjects in the study. When the level was reduced to 0.093 mg/m3 no conditioned reflex was noted. Men'shikova recommends a PSC value of 0.1 mg/m3. C-32 7° ------- Carter, et al. (1977) described a study on dibutyl phthalate and the resultant testicular atrophy which oc- curred. In the study, the ester was dissolved in corn oil and administered orally (by intubation) for a period of time. The dose administered was 2000 mg/kg while control animals received corn oil in a volume of 5 ml/kg. The initial ef- fect noted was a progressive reduction in weight of the testes. In 14 days, the reduction amounted to 60 to 70 per- cent of the original weight. Since there was also a decrease in body weight, the authors used "relative testes weight" and found that even in this manner of reporting there was still a significant loss (testes weight). Histopathological methods on testes tissue demonstrated morphological damage. Further investigations by these authors revealed that the ester ap- parently influenced zinc metabolism with an increase in the excretion of zinc in urine. It was visualized that after oral administration dibutyl phthalate is metabolized by non- specific esterases in the gastrointestinal tract to the mono- butyl phthalate prior to absorption into the bloodstream. Results from the various experiments have led the authors to suggest that the monoester or another metabolite of dibutyl phthalate may be acting as a chelating agent by removing the zinc from the testes. The deficiency of zinc in testes tis- sues is, according to the authors, the causative factor lead- ing to the atrophized organ. Milkov, et al. (1973) reported in 1969 that a group of esters in an industrial environment produced various degrees of toxic polyneuritis. These investigators studied 147 C-33 ------- persons (87 women and 60 men) the majority of whom were not more than 40 years old. These industrial workers were ex- posed primarily to dibutyl phthalate but other esters appar- ently were also present but in much less concentrations. These included dioctyl, diisooctyl and benzyl butyl phthal- ates. Also, in some instances there were small amounts of sebacates, adipates and tricresyl phosphate. Until more occupational studies are performed, the re- port by Milkov, et al. (1973) must be taken with some reser- vation because of the presence of other chemical agents such as tricresyl phosphate, an agent known for inducing poly- neuritis. Dibutyl (Diethylene Glycol Bisphthalate) (DDGB): Hall, et al. (1966) studied the tcxicity of DDGB. They used a commercial sample which also contained 15 percent dibutyl phthalate and 5 percent (diethylene glycol) phthalate. The oral LDjQ of this product in rats was found to be greater than 11.2 g/kg and the i.o. LD5Q approximately 11.2 g/kg. A 12-week toxicity study was conducted on the product using rats as the test animals. Diets in different groups of rats contained 0, 0.25 and 2.5 percent of the product, respec- tively. Over the period of the study, there was a marked re- duction of growth in the treated animals as compared with the control group. Also evident were enlargements of the liver and heart at the 1.0 and 2.5 percent levels in male rats and enlarged brain in both male and female animals. At the 2.5 C-34 "V7 ------- percent level, oxaluria and hematuria were found in both sexes, the oxaluria being assumed to be a direct consequence of the in vivo liberation of diethylene glycol (a known pro- ducer of oxalate stones in the bladder). Butyl Benzyl Phthalate: Mallett and Von Hanun (1952) ad- ministered both orally (1.8 g/kg) and i.p. (4 g/kg) butyl benzyl phthalate to groups of rats. Animals died after four to eight days and histopathological studies demonstrated tox- ic splenitis and degeneration of central nervous system tis- sue with congestive encephalopathy. Further, myelin degener- ation and glial proliferation were reported. Dialkyl 79 Phthalate: This product contains a mixture of phthalate esters of alcohols having chain lengths of seven to nine carbons. In a 90-day feeding study in rats by Gaunt, et al. (1968) no demonstrable adverse effects were noted at diet levels of 0.125 percent, but at the 0.5 and 1.0 percent levels, increased liver weights were observed even though histopathological changes were not seen. The authors con- cluded that a 60-kg adult could ingest 36 mg/day without any apparent harm. Di-2-ethylhexyl Phthalate (DEHP): As has been indicated a number of times, this ester is the most used phthalate and for this reason more toxicological data are available on it than any of the other esters. It should be remembered that DEHP is often used synonymously with the dioctyl phthalate and, even though they are isomers, they have slightly dif- ferent biological properties. C-35 ------- The acute oral toxicity is very low, ranging from 14.2 to greater than 50 g/kg before lethality will occur in ro- dents. Dermal absorption will occur but in rabbits approxi- mately 25 ml/kg need to be applied to the skin to cause death. Inhalation toxicity is also extremely low due to the very low volatility of the ester. In 1945, Shaffer, et al. (1945) reported a 90-day sub- acute toxicity study in rats. Groups of animals were given in feed 3.0, 1.5, 0.75 and 0.375 percent of the ester which approximates daily intakes of 1.9, 0.9, 0.4 and 0.2 g DEHP/kg per rat in the four treated groups while the fifth group served as a control (no phthalate). At the three higher levels, a slight decrease in growth was noted when compared to the control animals. At the 3.0 and 1.5 percent doses, tubular atrophy and degeneration in the testes were observed. No deaths occurred in any of the treated animmals while blood cell counts, hemoglobin concentrations and differential white cell counts remained normal. The authors concluded that a no adverse effect from oral administration would occur at ap- proximately 0.2 g/kg/day or less while only a slight retarda- tion in growth may occur when the dose is increased to 0.4 g/ kg/day. Carpenter, et al. (1953) conducted a study on chronic oral toxicity of DEHP using rats, guinea pigs and dogs. In the rat study, parental (P^) generation rats received daily diets containing 0.4, 0.13 and 0.04 percent of DEHP for a maximum period of two years. In addition, a group of fil- ial generation (F^) rats were given in feed 0.4 percent of C-36 V'/ ------- DEHP for one year. Control groups of rats were maintained on the same basic diet without the ester. The investigators ex- amined the following signs and symptoms of toxicity: mortal- ity, life expectancy, body weight, food consumption, liver and kidney weights, micropathological changes, neoplasm, he- matology and fertility. Over the two-year period for the PJ group and over a one-year period for the F^ group, a number of deaths oc- curred ,. However, these deaths were not attributed to the es- ter since they were also noted in the control animals. The mean liver and kidney weights, as percentage of body weights, were found to be increased over those of the con- trols in both the initial group (PI) and their offspring (FI> which had received the diet containing 0.4 percent DEHP. The results were statistically significant. Histo- pathological examination of the liver and kidney tissues of treated animals did not reveal statistically significant dif- ferences from organs of control animals. The authors did suggest that even though pathological changes in the two or- gans of treated groups were not different from control ani- mals, the increase in size of the organs may indicate a toxic response. Results from comparisons of life expectancy, body weight, food consumption, neoplasia, hematology and fertility in the treated animals were found not to differ significantly from controls. In another study by the same investigators (Carpenter, et al. 1953), groups of guinea pigs were administered in diet 0.13 and 0.04 percent DEHP for one year. Similar criteria, C-37 'H f \ ------- with the exception of hematology and fertility, as used in the rat study were employed. Liver weights, as percentage of body weights, were found to be statistically higher in the treated groups than in the control animals. The authors pointed out that the effect was not related to the concentra- tions since both treated groups appeared to be about the same in regard to liver weight. The other parameters studied were found not to be significantly different from control animals. A "no effect" dose for DEHP in guinea pigs (for one year) was estimated to be 0.06 g/kg/day. A one-year study was also reported by Carpenter, et al. (1953). In this study, dogs were administered capsules with 0.013 ml/kg/day DEHP, five days a week, for the first 19 doses and then 0.06 ml/kg/day until 240 doses had been admin- istered. No statistically significant adverse effects were seen. The authors concluded that a "no effect" dose in dogs would be approximatley 0.06 g/kg/day. Harris, et al. (1956) published a paper which, in ef- fect, confirmed the results of Carpenter, et al. (1953). A chronic oral toxicity study in male and female rats was con- ducted in which groups of animals received in their feed 0, 0.1 and 0.5 percent DEHP. At various time periods, rats were sacrificed and food consumption, body weight, and liver, testes, kidneys, lungs, brain, stomach, heart and spleen weights recorded. Histopathological studies were also con- ducted on selected tissues and organs. The study was termi- nated after 24 months. Significant increases in liver and kidney weights were noted at the 0.5 percent dose level for C-38 ------- the three- and six-month sacrifices. At the one- and two- year periods, no real differences in the liver and kidney weights were apparent in any of the groups, but the authors point out that this may have been due to the small number of rats remaining after these longer periods. No unusual pa- thology was noted in the tissues and organs prepared for microscopic examination which could be attributed to the ester. Slight body weight reduction was seen at the 0.4 and 0.5 percent dose. Food consumption was decreased at the 0.5 percent level when compared to the control animals. In a dog study, Harris, et al. (1956) reported a mild toxic effect within three months when a dog was administered 5 g/kg/day of DEHP but not with 0.1 g/kg/day. The small num- ber of dogs in this study (two) and relatively short period of study (14 weeks) do not permit a valid conclusion to be made of the chronic effects of DEHP on dogs. However, this data associated with the data of Carpenter, et al. (1953) suggests that a no-effect dose in dogs is approximately 0.1 g/kg/day. Lawrence, et al. (1975) studied the subchronic toxicity of a number of phthalate esters to determine the chronic LD50 by the i.p. route. Groups of male mice were administered a range of doses for each of the esters, five days a week, and an apparent LD5Q calculated for that week. This dosing schedule was continued until two criteria were met. These included: (1) mice injected for at least ten weeks, and (2) the apparent L?$Q remained constant for three consecutive C-39 ------- weeks. DEHP and DOP were included in the list of esters studied. The first week, the LD5Q for DEHP was 38.35 ml/kg and 67.18 ml/kg for DOP. The second week, the LD5Q was re- duced to 6.40 ml/kg for DEHP and 25.51 ml/kg for DOP. By the end of the 12th week, the LD5Q was reduced to 3.09 ml/kg for DEHP and to 1.37 ml/kg for DOP. A cumulative toxicity factor was calculated for each of the esters (acute LD5Q/chronic LDso) and for DEHP this value was 27.99 (indicating that the toxicity had increased by this factor). A similar calcula- tion for DOP came to 21.74. The other esters had cumulative toxicity factors ranging from 2.05 to 4.01, indicating that cumulative toxicity was only minimal over the time period the animals were studied. The implication of the high cumulative toxicity factor for both DEHP and DOP is not clear and the reasons for these results, when compared to the other esters, are presently not explainable. It is possible to speculate that very high exposure doses prevent the body from eliminat- ing the compound and metabolites to the same degree as occurs when repeatedly lower doses are administered. It is also not known if oral doses would have led to the same or similar re- sults, since this type of administration was not done in the study by Lawrence, et al. (1975). Earlier studies by Shaffer, et al. (1945) Carpenter, et al. (1953) and Harris, et al. (1956), demonstrated the low chronic toxicity of DEHP but they also noted that at the higher daily doses kidney and liver enlargement occurred. C-40 ------- These investigators, however, could not find light micro- scopic evidence of injury to these organs using histopatho- logical methods. The enlargement of an organ such as the liver may not necessarily indicate that a toxic event has occurred, as suggested by Golberg (1966). In studies by Lake, et al. (1975), rats were orally dosed with DEHP in corn oil at a concentration of 2000 mg/kg/day for periods of 4, 7, 14, and 21 days. Control ani- mals received 0.5 ml/100 g body weight of the vehicle. The investigators noted relative liver weight increased progres- sively during the treatment to 215 percent of the controls at the end of 21 days. Liver homogenates were prepared for each time period and the following biochemical activities and/or levels determined (for each of the time periods): succinate dehydrogenase, aniline 4-hydroxylase, biphenyl 4-hydroxylase, glycose-6-phosphatase, cytochrome P-450? protein contents, and alcohol dehydrogenase. Alcohol dehydrogenase activity and microsomal protein and cytochrome P-450 contents in- . creased markedly initially but then decreased during the time of treatment. On the other hand, microsomal glucose-6-phos- phatase, aniline 4-hydroxylase and mitochondrial succinate dehydrogenase activity decreased significantly. Electron microscopy of liver tissue of treated animals demonstrated changes in hepatocytes* At the end of seven days, there was an increase in microbodies and there also appeared to be a dilation of the smooth endoplasmic reticulum and swelling of the mitochondria. 041 ------- Lake, et alo (1975) studied the monoester and found that liver changes in treated rats closely resembled those pro- duced by DEHP0 They concluded that in general the toxic effects of DEHP are due to the metabolite , mono-2-ethylhexyl phthalate. Daniel and Bratt (1974) fed dietary concentrations of 1000 and 1500 ppm of i4C»DEHP to groups of female rats for 35 and 49 days respectively,, Two animals from each group were sacrificed at various intervals and the heart, brain, liver, and abdominal fat removed for radiochemical analysis. Re- maining animals were returned to a normal diet and sacrificed at intervals during the subsequent two to three weeks and tissues prepared for analysis,, At the 5000 ppm level, liver weight relative to total body weight increased progressively during the first week to a value approximately 50 percent above the control and remained constant in the remaining time period. Electron microscopy of liver tissue revealed only a slight increase in the amount of smooth endoplasmic reticu- lum. Returning animals to a normal diet resulted in liver weight returning to normal „ There was no apparent change in liver weight in those animals receiving the 1000 ppm DEHP. Additional studies by these authors did not reveal the ac- cumulation of DEHP j.n body organ tissues. Nikonorow,, et alo (1973) reported that a daily dose level of 0.35 percent (in feed) of DEHP caused a decrease in body weight of rats after 12 months. In other chronic studies on DEHP, livers of treated animals were significantly larger than livers from control animals not receiving DEHP. 042 ------- Kevy, et al. (1978) studied the toxic effects of DEHP solubilized in monkey blood or blood products by storing the animal blood (or blood product) in PVC blood bags. These products were then transfused into the animals for time periods ranging from six months to one year. This dosing program attempted to mimic actual transfusion levels expected in selected patients requiring large-volume blood or blood products. The total concentration of DEHP received by the monkeys ranged from 6.6 mg/kg to 33 mg/kg. Liver damage was noted by several sensitive tests (hepato-splenic ratio using an isotopic technique and BSP kinetic compartmental analyses) as well as routine light microscopy of liver tissue. Even up to 32 months after the last transfusion, liver changes per- sisted. DEHP was also found in liver tissue in treated ani- mals many months after the last transfusion. The work of Kevy and associates has significance since DEHP can enter man through various PVC medical devices. Mild-to-moderate hepatic toxicity may occur depending upon the dose, the fre- quency of exposure, and the health status of the patient. Biochemical studies on rat blood and liver at 21 days after injection of 5 ml/kg DEHP i.p. on days one, five and ten produced the following results: a decrease in the activ- ity of succinic dehydrogenase and an increase in alkaline phosphatase activity in the liver; serum enzyme values were not altered. This study was conducted by Srivastava, et al. (1975) who pointed out that DEHP may also play a role in interfering with energy metabolism of the cell. 043 ------- Though it is recognized that different routes and dosage forms will alter the pharmacokinetic disposition of com- pounds, DEHP from several different routes (oral, i.p., i.v.) can produce hepatotoxic responses depending upon the specific dose and the frequency of exposure. Seth, et al. administered i.p. 5 ml/kg of DEHP (undi- luted) to 10 male and 20 female rats on days one, five and ten. On the 22nd day of the study, all animals were sacri- ficed and one test is or ovary was removed and retained for enzymatic studies. A control group of rats received an equal volume of saline. Results of the study demonstrated that the scrotums in all animals were enlarged but no gross abnor- mality was discerned. Succinic dehydrogenase (SDH) and ade- nosine triphosphatase (ATPase) activities were significantly reduced while that of ^-glucuronidase was increased in both organs of the test animals. Histopathologic examination of the testes of the animals revealed degenerated tubules show- ing marked vacuolization of the cytoplasma of spermatogonial cells and eccentric nuclei. No apparent alterations (histo- pathologic) were noted in the ovaries of the DEHP treated rats. Carter, et al. (1977) alluded to an unpublished study on DEHP in which rats were fed various dose levels of the ester for 90 days. At a daily level of 0.2 percent DEHP produced testicular injury,, Whan the level of DEHP was increased to 1.0 percent, testicular injury was noted in two weeks. The authors further state that DEHP and dibutyl phthalate have about the same potency in causing testicular atrophy in rats. C-44 ------- Even though mention was made that other esters of phthalic acid were studied no data were presented. Thus, the reader may assume that these other esters did not have the same \ toxic properties to testes as either DEHP or the dibutyl ester. It seems possible that DEHPf like dibutyl phthalate, may affect zinc metabolism in the testes which, in turn, may be the causative factor in bringing about atrophy of the organ. In a series of papers, Bell, et al. (1976, 1978) have demonstrated that feeding rats DEHP can have an effect upon lipid metabolism including inhibition of hepatic sterolo- genesis, inhibition of fatty acid oxidation by heart mito- chondria, stimulation of fatty acid oxidation by hepatic mitochondria, and an ability to modify the pattern of circu- lating plasma lipoproteins. In several of the studies, rab- bits and pigs were also used and led to the conclusion that the response of mammalian tissues to phthalate esters is var iable depending upon the species. The toxic implications of alteration in lipid metabolism to man is presently obscure. The toxic properties of DEHP are most likely related to the formation of the monoester (in the gut or liver) and/or to other metabolites produced in the body. Studies by Lake, et al. (1975) demonstrated that neither phthalic acid nor 2-ethylhexanol reproduced the toxic effect of DEHP, suggest- ing that the metabolites must play the major factor in pro- ducing a toxic response. It also appears that man, rat, baboon and ferret may handle DEHP as well as other esters in a similar manner (Lake, et al. 1977). C-45 ------- Synergism and/or Antagonism There are no data available on the synergism or antagonism of phthalate esters. Teratogenicity Singh, et al. (1975) included eight phthalic acid esters in a rat teratogenic study. The esters included the follow- ing: dimethyl, dimethoxyethyl, diethyl, dibutyl, diisobutyl, buty carbobutoxymethyl, dioctyl and di-2-ethylhexyl phthal- ates. For all the esters, except two, the dose administered i.p. to pregnant female rats was 1/10, 1/5, and 1/3 the acute LD5Q. For these esters, the doses ranged from a low of 0.305 ml/kg for dibutyl phthalate to a high of 2.296 ml/kg for butyl carbobutoxymethyl phthalate. Di-2-ethyhexyl phthalate and dioctyl phthalate were given at doses of 5 and 10 ml/kg because of their very low acute toxicity. Control groups in- cluded: untreated rats, rats treated with 10 mg/kg of dis- tilled water, rats treated with 10 ml/kg of normal saline and rats treated with 10 ml/leg and 5 ml/kg of cottonseed oil. All treatments took place on days 5, 10, and 15 of gestation. On the 20th day, all the rats Were sacrificed and the uterine horns and ovaries were surgically exposed to permit counting and recording of the numbeir of corpora lutea, resorption sites, and viable and dead fetuses. Additionally, both vi- able and non-viable fetuses were excised, weighed, and ex- amined for gross malformation. From 1/3 to 1/2 of the fetuses, using those which showed no gross malformation when possible, were prepared as transparent specimens to permit visualization of skeletal deformities. C-46 ------- All of the esters produced gross* or skeletal abnormal- ities which were dose related. The most common gross abnor- malities in the treated animals were absence of tail ano- phthalmia, twisted hands and legs, and hematomas. Skeletal abnormalities included elongated and fused ribs (bilateral and unilateral), absence of tail bones, abnormal or incom- plete skull bones, and incomplete or missing leg bones. Dead fetuses were found in the groups treated with dimethyl, di- methoxyethyl and diisobutyl phthalates. The most embryotoxic agent in the series was dime thoxyethyl phthalate. Each of the esters also reduced the weight of the fetuses when com- pared to the controls. Even at the high dose levels (5 and 10 ml/kg), di-2-ethylhexyl and dioctyl phthalates had the *> least adverse effects on embryo fetus development. Since the study by Singh, et al. (1972) was carried out i.p., results should not be extrapolated to possible terato- genic effects if the compounds had been administered orally or by other routes. In another study by Peters and Cook (1973), pregnant rats were administered i.p. 4 ml/kg DEHP on days three, six and nine of gestation. At this dose level, implantation was prevented in four of five rats. When the dose was reduced to 2 ml/kg, a similar response was noted in three of five rats. These authors also noted adverse effects on parturition in dams treated with DEHP such as excessive bleeding, incomplete expulsion of fetuses and maternal deaths. Teratogenic studies on dibutyl and dimethyl phthalates were also con- ducted by these authors, but the adverse effects were less C-47 ------- than those observed for the DEHP-treated rats. It was inter- esting to note that adverse effects prior to gestation day six were primarily on implantation, while -after this day the effect was primarily on parturition. In another study by Singh, et al. (1975), rats were in- jected i.p. with labeled di-2-ethylhexyl phthalate and di- ethyl phthalate. The results demonstrated that these phthal- ates could pass through the placental barrier suggesting that the embryo-fetal toxicity and teratogenesis of the phthalic acid esters could be the result of the direct effect of the compound (or its metabolites) upon developing embryonic tissue. Bower, et al. (1970), studied the effects of eight, com- mercial phthalate esters in chick embryos. They found that dibutyoxyethyl phthalate, di-2-methoxyethyl phthalate and octyl isodecyl phthalate produced damage to the central ner- ® vous system of the developing chick embryo when compared to control embryos receiving an oil and to an untreated group. In a study reported by Nikonorow, et £l. (1973), preg- nant rats were administered orally 0.34 and 1.70 g/kg/day of DEHP during the gestation period. Another series of rats re- ceived orally 0.120 and 0.600 g/kg/day of dibutyl phthalate. Olive oil was used as a control and administered in a similar manner as the esters to a group of rats. There was a statis- tically significant reduction in fetus weight at both dose levels for DSHP but only at the higher dose level for the dibutyl phthelateo The number of resorptions were noted for DEHP at bcth dose levels but only at the higher dose level for dibutyl phthalate. No detectable differences were C-48 ------- observed in the number of sternum ossification foci, develop- ment of the bones at the base of the skull, paws of the front and hind legs, and rib fusion in fetuses when compared to the control animals. Since the quantity of phthalate esters ingested by hu- mans on a daily basis is extremely small as compared to the doses used in the previous studies, it seems remote that teratogenic effects would be produced in humans. Further studies in which the esters are administered orally to preg- nant females should, however, be carried out to verify this assumption. Mutagenicity Studies of the effect of phthalic acid esters on genetic changes in animals are not adequate to conclude if one or more of these compounds presents a threat to animals and man. One of the few studies published on this topic is by Singh, et al. (1974). These authors included DEHP and dimethoxy- ethyl phthalate (DMEP) in a study on the mutagenic and anti- fertility effects in mice. The experiment followed the gen- eral procedure used in conducting the dominanat lethal assay for mutagens. A group of ten males were injected i..p. with each compound at three doses. For the DEHP, the doses were 1/3 (12.8 ml/kg), 1/2 (19.2 mlAg), and 2/3 (25.6 ml/kg) of the LD5Q. A similar dose pattern was used for the DMEP or 1/3 (1.19 ml/kg), 1/2 (1.78 mlAg) and 2/3 (2.38 ml/kg) of the LD5Q. C-49 ------- Each group of male mice was injected with the doses shown above and, immediately following injection, each male was caged with two virgin adult female mice. Each week for 12 weeks, two new virgin females replaced the previous week's female mice. Results of the study indicated that at the high dose of both esters a distinct reduction in the incidence of pregnan- cies occurred. Fewer effects were noted at the lower dose levels. DEHP appeared to have a more persistent effect over the time period studied than DMEP. Both esters produced some degree of dose- and time-dependent antifertility and mutagenic effect. Early fetal deaths occurred indicating the potential mutagenic effects of these compounds. The increase in early fetal deaths was not large, however, it was above the values for the control animals. Rubin, et al. (1979) included a number of phthalate esters in an Ames mutagenic assay. The esters included: dimethyl, diethyl, dibutyl, mono-2-ethylhexyl, di-2-ethyl- hexyl and butyl benzyl phthalate as well as phthalate acid. Positive responses were found for the dimethyl and diethyl phthalates. The remaining compounds were found to be non- mutagenic under the test conditions. Studies by Turner, et al. (1974), showed the DEHP did not produce genetic damage in lymphocytes but did inhibit mitosis and growth. It is clear that more studies on the mutagenic effects must be conducted before a definite conclusion can be made concerning the risk of a population exposed to the phthalate C-50 ------- esters. The antifertility effect appears to be much stronger and the question which still needs to be answered is what ef- fects would lower doses have upon males repeatedly exposed to these esters. Epidemiological evidence on this subject is lacking, and thus human risks cannot accurately be por- trayed. Carcinogencity A recent report by Rubin, et al. (1979), alluded to under Mutagenicity in which an in vitro mutagenic assay was conducted on a group of phthalate esters (dimethyl, diethyl, dibutyl, mono-2-ethylhexyl, di-2-ethyhexyl and butyl benzyl phthalates) and on phthalic acid showed that both dimethyl and diethyl phthalates produced a positive response suggest- ing but not proving that these compounds may have a cancer liability. A long history of use of both of these compounds, however, has not implicated these as even weak carcinogenic agents. It would appear, however, that consideration should be given to cancer studies of these two esters in animal models to ensure that a potential cancer threat does not exist. Other Biological Effects Cellular Toxicity: In recent years, a number of in vitro tests have become useful in assessing the toxicity of chemicals. Even though the results may net-always be extra- polated to animals or humans, the proper in vitro system can generate very useful data which can assist in determining the toxic consequences of a chemical. Tissue and organ culture methods are now widely used toxicity testing methods. C-51 ------- Nematollahi, et al. (1977) synthesized and purified a number of phthalic acid esters and then included them in a toxicity screening program using two cell lines (chick embryo and L-cells). The esters, as solids or liquids, were placed on the surface of agar which overlaid the cells. A vital dye was also included in the cells. For the solids, 20 mg of the ester were placed on the surface while for the liquids, 35 mg of the ester were placed on a paper disk which was previously placed on the agar. After 24 hours of incubation, the cells were examined for cytotoxicity. Table 8 includes the results of the screening tests. In the same table are the results from a mouse t.oxicity test. Three mice were injected i.p. at a concentration level of 5 moles/kg in either cottonseed oil or castor oil, depending upon the solubility of the specific compound. As will be seen from the table, the lower molecu- lar weight esters were cytotoxic and lethal to mice. Several of the highest molecular weight esters also demonstrated some signs of toxicity. Jacobson, et al. (1974), found that solubilized DEHP in serum inhibited cell growth (normal diploid fibroblasts established from skin) in tissue culture experiments. A con- centration of 0.18 mM, which is equivalent to that in 21-day- old whole blood stored at 4°C, inhibited cell growth by 50 percent. A 20 percent reduction in cell growth occurred when the DEHP concentration was reduced to 0.10 mM which is com- parable to the concentration found in whole blood stored at 4°C for 14 days. C-52 /• r ------- TABLE 8 Results of the Toxicity Evaluation of Phthalate Esters on the Mammalian Cell Cultures and Mice Phthalates Chick Embryo Cells L-Cells Mice CH- n-C3H7 n-C4H9 iso—C4 n-C5Hu Cyclo-CsHg n-C6H13 n-C7H15 Cyclo-C n-C8H17 n-C10H2i n-c12H25 From: Nematollahi, et al. 1977. Note: In tissue culture test: + indicates cytotoxic; - in- dicates noncytotoxic; +_ indicates questionable results In mouse test: + indicates 2 or 3 deaths; - indicates no deaths; _+ indicates only one death. C-53 ------- In another tissue culture study, Jones, et al. (1975) reported the 1050 (concentration required to inhibit cell growth by 50 percent) on a number of phthalic acid esters. The IDso values are shown in Table 9. As will be noted from the table, IDso for DEHP came to 70 uM. In comparing this IDSO with the one reported by Jacobson, et al. (1974) (0.18 mM), it should be remembered that the Jacobson group reported the concentration they added to the culture medium, whereas Jones, et al. (1975), indicated the actual solubility in the medium. The 70 uM solubility concentration would be approxi- mately 0.05 mM which is in line with the Jacobson value con- sidering that slightly different techniques were employed. The most cytotoxic ester in the series was butyl glycolyl butyl phthalate. The IDso dose for a group of phthalate esters has been reported for mouse fibroblasts in cell culture (Autian, 1973). These values are included in Table 1C. It is inter- esting to note that the most cytotoxic agent in the series was DEHP, an agent having a very low order of acute toxicity in animals and man. As can be seen from the table, the tox- icity of these compounds in general increased as the molec- ular weight increased. A report by Dillingham and Autian (1973), indicates that dimethyoxyethyl phthalate is much more toxic to mouse fibro- blast cells undergoing significant rates of cell division than nonreplicating cells. This observation suggests that any tissue which undergoes periodic increases in protein C-54 j ------- TABLE 9 1050 Values for a Series of Phthalate Esters Using WI-38 Cells Agent (Phthalate) Di-n-butyl Di-iso-butyl Dime thoxy ethyl Butyl glycol butyl Di-n-octyl Di-2-ethylhexyl Molecular Weight 278 278 282 336 391 391 ID50 (UM) 135 85 3500 12 170 70 Solubility (mol/liter) 0.008 Very Low 0.040 Very Low Very Low Very Low Taken in part from Jones, et al. 1975. TABLE 10 1050 of a Group of Phthalic Acid Esters in Tissue Culture (Mouse Fibroblasts) Ester Dimethyl Diethyl Dibutyl Dime thoxy ethyl Di-2-ethylhexyl Molecular Weight 194 222 278 282 390 Water Sol. (mole/1) 0.0263 0.0048 0.008 0.0400 0.0004 ID I°50 0.007 0.003 0.0001 0.0084 0.00005 Taken in part from Autian, 1973, C-55 ------- turnover related to changes in cell division rate and meta- bolic activity (protein synthesis) may increase the suscepti- bility of these cells to the toxic effects of phthalic es- ters. Thus, it is possible that the teratogenic and embryo- toxic effects of several of the esters reported in rats may be due to the fact that differentiating embryonic tissues have periodic major changes in cell division rates and meta- bolic activity in contrast to somatic cells which have a much lower rate of cell division and metabolism of the somatic tissue. Kasuya cultured cerebella from newborn rats and tested three phthalate esters (dimethyl, diethyl and dibutyl phthal- ates). Various concentrations of each of the esters were dissolved in calf serum and then added to the cells. The overall toxicity to the cells was in the following order: DBP>DEP>DMP. As will be noted, the toxicity of the three esters increased with molecular weight similar to cell cul- ture results reported by Dillingham and Autian. At a concentration of 4 vg/ml in tissue culture media, DEHP produced complete cessation of beating chick embryo heart cells maintained in tissue culture (Rubin and Jaeger, 1973). Up to 98 to 99 percent of the cells were found to be dead within a 24-hour period. This result, along with the other tissue culture reports, reinforces that DEHP is highly toxic at the cellular level. Blood Components/Lungs/Heart: In the past there has i been concern that DEHP, wheA extracted from medical devices such as blood bags and tubipgs, might have a deleterious 056 ------- effect upon blood components and also lead to the syndrome referred to as "shocked lungs." DEHPf solubilized with a surfactant and injected i.v. in rats, produced lung involve- ment and death. Stern, et al. (1977) have stressed the importance of the physical form of DEHP when injected i.v.: the naturally solubilized DEHP showing a "non-toxic" effect while DEHP solubilized with a surfactant produced a toxic effect. Rubin (1975) reported that DEHP, solubilized with a sur- factant and injected i.v. in rats, produced a biexponential disappearance of the DEHP from blood with half-lives of 3.5 and 35 minutes. A naturally solubilized DEHP, on the other hand, has a monoexponential disappearance with a half-life of 19 minutes. In humans, Rubin (1975) found that the half-life of naturally solubilized DEHP led to a monoexponential rate with a mean half-life of 28 minutes. Rats administered the surfactant solubilized DEHP showed death and lung involvement similar to the shocked lung syndrome (Rubin, 1975). Hypotensive rats, in which DEHP is added to the animal's own blood and then transfused back into the rat, produced hemorrhagic lungs in each of the six rats used in the experi- ment (Rubin, 1976). Control rats, treated in a similar man- ner but not receiving any DEHP, did not demonstrate the toxic lungs. Herman, et al. (1977) conducted studies in which rats were administered blood or blood components, previously in contact with PVC strips, to detect the effect DEHP (extracted from the plastic) would have on lung tissue. ACD-preserved C-57 ------- rat blood was stored in glass vials alone or in the presence of sterile plastic strips. One set of plastic strips was also enriched with 34 percent DEHP. After' storage for two weeks, 0.5 ml of blood were administered i.v. to groups of rats in the following forms: as whole blood, as whole blood minus platelets and buffy coat, as platelet-rich plasma, as platelet-poor plasma. Additional groups of rats received CPD-preserved rat or human blood after storage in glass alone or in glass containing PVC strips and/or PVC enriched with DEHP. Concentration cf DEHP in whole blood in contact with PVC was 81.5 ug/ml and 90.2 ug/ml for the blood in contact with PVC enriched with DEHP. Evans Blue was used as an indicator to detect the per- meability of excised lung tissue. Animals given ACD-pre- served blood which had contact with PVC demonstrated an in- creased permeability when compared to control animals. Administration of platelet-rich and platelet-poor plasma showed no significant increase in lung permeability. CPD- preserved blood in contact with the plastic strips showed an increased permeability which was greater than the CPD blood used as controls but not as great as the permeability shown by the ACD-preserved blood. Histopathologic examinations of lungs having received blood in contact with PVC and PVC en- riched with DEHP showed variable degrees of septal thicken- ing, perivascular edema and perivascular accumulation of mononuclear cells when compared to lungs of control rats. The authors suggest that blood-plastic contact during storage c-sa ------- may adversely affect blood and also the effects may be in part due to accumulation of DEHP in red cells. It has also been found that PVC infusion containers, if agitated, will produce liquid particles 'of DEHP which, in turn, can be administered to humans (Needham and Luzzi, 1973). Depending upon the size-frequency of these particles and the concentration of DEHP released to the solution, pos- sible toxic effects may result even though human experience has not yet indicated that adverse effects have occurred. Vessman and Rietz (1978) have reported the presence of mono-2-ethylhexyl phthalate (hydrolysis product of DEHP) in blood plasma stored in PVC blood bags. Ten blood bags with plasma were removed from storage (-20°C) and the monoester was found to range from 4 to 56 ug/ml. Eight of the plasma samples were then transferred to glass bottles and stored at room temperature. After two weeks of storage the monoester contents had increased to values between 27 and 79 ug/nil. Fractionated proteins albumin also contained the monoesters in amounts from less than 3 to 290 ug/g- The authors suggest that the conversion of DEHP in plasma is due to some enzymatic activity taking place in the product. They indi- cate that when measuring DEHP content of blood and blood pro- ducts stored in PVC bags, attention should also be given to determining the monoester content, thereby gaining a true picture of phthalate content. Sleeping Time: Sleeping time experiments were reported by Rubin and Jaeger (1973) who studied the effect of DEHP and C-59 .> / ------- butyl glycolyl butyl phthalate. These esters were also emul- sified with acacia and injected at 250 mg/kg and 500 mg/kg dose levels. After 30 minutes, hexobarbital solution was ad- ministered i.p. A significaant increase in sleeping time was produced by DEHP at both dose levels, while only the higher dose of butyl glycolyl butyl phthalate produced a longer sleeping time than the control animals. Rats were also em- ployed by the authors in a similar sleeping time experiment with the results being similar but the magnitude less than with the mice. Rubin and Jaeger (1973) conducted additional experiments and concluded that the increase in hexobarbital sleeping time was not due to an increase in CNS sensitivity to hexobarbital nor an alteration in rate of hexobarbital metabolism by the liver, but to the effect of DEHP in the distribution of hexobarbital into various organs. Swinyard, et al. (1976) also found an increase in hexo- barbital sleeping time from DEHP. It was interesting to note that olive oil also produced an increased sleeping time simi- lar to DEHP. These authors concluded that the effect of DEHP was nonspecific due to the physical characteristic of the es- ter which enlarged the lipophilic reservoir for hexobarbital rather than to a pharmacological property of the compound. Daniel and Bratt (1974) noted that hexobarbital sleeping time (in rats) was increased when DEHP was used at a dose of 600 mg/kg of emulsified agent. When rats were given orally five successive daily doses of DEHP (500/kg) hexobarbital sleeping time was decreased. C-60 ------- From the information available, it is clear that DEHP prolongs the sleeping time of short-acting barbiturates. In the instance of acute studies, the cause of the prolongation of sleeping time may, in fact, be due to nonspecific factors, probably to the lipophilic reservoir mechanism advocated by Swinyard, et al. (1976). On the other hand, repeated pre- treatments with DEHP may have an effect upon the liver and enzyme systems. Since liver involvement has been noted by several investigators ir. subacute toxicity studies in rats and monkeys, the DEHP may, in these cases, be producing a specific toxicological effect. C-61 ------- CRITERION FORMULATION Existing Guidelines and Standards The Threshold Limit Value for dimethyl, dibutyl and di- 2-ethylhexyl phthalate esters established by the American Conference of Governmental and Industrial Hygienists is 5 mg/m^. The Food and Drug Administration has approved the use of a number of phthalate esters in food packaging materials. Prior to 1959 (before enactment of the food additive amend- ment), FDA approved five esters. These are: diethyl phthal- ate, diisobutyl phthalate, ethyl phthalyl ethyl glycolate, diisooctyl phthalate and di-2- ethylhexyl phthalate. Since then, 19 additional phthalates used in packaging material for foods of high water content have also been approved. More specific uses and restrictions .of phthalic esters are set forth by FDA in its regulations. Current Levels of Exposure Lack of sufficient data prevents an accurate assessment of levels of exposure of man and animals to phthalate esters. Is is now, however, well known that man is exposed to these esters throuoh a number of routes such as industrial sites in which the esters are manufactured or used. Esters may also reach man through indirect means such as inhalation of the esters inside vehicles containing PVC products firom foods and from water. Direct injection i.v. of specific phthalate es- ters can also occur when PVC blood bags and tubings are used to transfuse blood and blood products to man. The ubiquitous C-62 ------- nature of the phthalate ester is apparent since tissues of deceased persons have revealed the presence of phthalic acid esters, even though the individuals were not apparently ex- posed to these esters. Even though it is well established that workers in occu- pations in which phthalate esters are used are exposed to various levels of phthalate esters and thus can absorb these esters through inhalation or through dermal absorption, the lack of sufficent data precludes establishing what are the levels of exposure. Dermal absorption of the low molecular weight esters such as dimethyl phthalate (mosquito repellent) and diethyl phthalate (in cosmetic products) probably is also occurring but the quantity absorbed through the skin is not known. A survey was conducted by tha Bureau of Foods (FDA) in 1974 to determine if phthalate esters were entering the food supply through the processing, packaging, handling and trans- portation chain. In the study, ten basic and stable food products were analyzed for the presence of these esters. Conclusions reached in the report are presented below: 1. The frequency and levels of phthalate esters re- ported as well as the possible cumulative intake of phthalates in baked beans in cans or jars, can- ned whole kernel corn, margarine, cereals, eggs, bread, corn meal, meat, milk, and cheese do not pose a hazard to the consumer. 2. DEHP was the ester most frequently detected in the food commodities. Dibutyl phthalate, dicyclohexyl phthalate and butylphthalylbutyl glycolate were found in comparatively few samples. Diisoctyl and diisodecyl phthalates, although looked for, were not detected. C-63 ------- 3. Phthalate ester contamination was found in a higher proportion of milk and cheese samples than in other foods. (However, the findings are uncer- tain. ) In the above survey, the highest levels of phthalate esters were present in margarine (13.7 and 56.3 ppm on fat basis). In cheese, the highest levels of esters were 22.8 and 24.9 ppm for DNBP and 35 ppm for DEHP but most cheese samples contained less than 5 ppm of phthalates. In a published study by Tomita, et al. (1977), informa- tion is presented dealing with phthalate (DEHP and DNBP) residues in various commercial foodstuffs in Japan. They concluded that foods packaged in plastic films with printing are a greater source of contamination to the product with the esters than if the foods were in plastic bottles. They also noted that persons had significantly higher levels of the esters after meals from foods packaged in the film. Ex- tremely high levels of the two esters (combined) were found in tempura powder stored for eight months (up to 454 ppm). The residue level of the esters from plastic films containing the plasticizers, as would be expected, migrated to fatty foods or fatty-like foods to a greater extent than to foods having low fat content. The authors included in their con- clusion the following: "The daily intake of PAEs (phthalic acid esters) from present foodstuffs may not exceed the ADI of DNBP and DEHP but an effort to reduce the PAE levels in foodstuffs should be continuously made." C-64 ------- The Bureau of Foods (FDA) in another survey on fish from a number of locations in the U.S. noted that the highest level of DEHP (7.1 ppm) was present in shark (smooth, hound). In most other instances , the fish which were studied were free of the esters. Patients receiving repeated transfusions with whole blood, packed cells, platelets and plasma stored in PVC may receive up to 70 mg of DEHP and, in some instances, the quan- tity even exceeds 500 mg. Hemodialysis patients may receive up to 150 mg of DEHP,, Special Groups at Risk Two groups are at risk in regard to phthalic acid es- ters. These are workers in the industrial environment in which the phthalates are manufactured or used and patients receiving chronic transfusion of blood and blood products stored in PVC blood bags<= Basis and Derivation of Criterion From the available information, the phthalic acid esters have not been found to be carcinogenic in animals or man. At "high doses when injected i0p=y the esters can act as terato- genic agents and possibly as mutagenic agents in rats. These esters also have an effect upon gonads in rats. Evidence is also at hand to show that the esters may bring about biochem- ical and pathological changes in the liver of rats when .re- peatedly administered orally or by i.p. When solubilized in blood components, DEHP has demonstrated liver involvement when these products have been repeatedly administered i.v. to monkeys. Inhalation studies in rats and man suggest that C-65 ------- certain phthalates may be responsible for neurological dis- orders, but these results need further verification since other non-phthalate esters may also have been present leading to the problems. Since a number of phthalate esters are in the environ- ment or may be present in water, it was thought appropriate to review chronic toxicity data in which well established chronic toxicity data for these esters were reported to establish an allowable daily intake (ADI). In calculating the API, an uncertainty factor of 100 was used based upon a 70 kg person. Table 11 taken from Shibko (1974), lists eight esters in which the "no effect" dose was established from chronic toxicity studies in rats or dogs. The table also includes the number of days the animals were fed the specific phthalate esters and the calculated ADI. It will be noted that the ADI ranged from a low of 9.8 mg/day for dicyclohexyl phthalate to a high of 700 mg/day for dimethyl phthalate. For the sake of establishing water quality criteria, it is assumed that on the average a person ingests 2 liters of water and 18.7 grams of fish. The amount of water ingested is approximately 100 times greater than the amount of fish consumed. Since fish may biomagnify the esters to various degrees, a biomagnification factor (F) is used in the calculation. Biomagnification factors for dimethyl, diethyl, dibutyl and di-2-ethylhexyl esters were derived by the U.S. E?A ecological laboratories, Duluth (see Inge$tion from Foods). C-66 ------- TABLE 11 Calculated Allowable Daily Intake in Water and Fish for Various Phthalate Esters 1. 2. 3. 4. n a\ ~~> 5. 6. 7. 8. ** *** Ester Dimethyl Diethyl Dibutyl Dicyclohexyl Methyl phthalyl ethyl glycolate Ethyl phthalyl . ethyl glycolate Butyl phthalyl ethyl glycolate Di-2-ethyhexyl No Effect Dose* (mg/kg/day) 1000 625 18 14 750 250 140 60 From: Shibko, 1974. Allowable Daily Intake for 70 kg F = Biomaanif ication factor. Species Rat Dog Dog Dog Rat Rat Dog Dog person (100 s Days 104 52 52 52 104 104 104 52 safety ADI** (mg/day) 700 438 12.6 9.8 525 175 98 42 factor) . F*** Recommended Criteria mg/1 130 160 270 60 26 5 Not Established Not Established Not Established Not Established 95 10 ------- Due to lack of data, bioconcentration factors could not be derived for dicyclohexyl, methyl phthalyl ethyl glycolate, ethyl phthalyl ethyl glycolate and butyl phthalyl ethyl glycolate. The equation for calculating an acceptable amount of ester in water based on ingestion of 2 liters of water and 18.7 g fish is: (2/1) X + (0.0187 x F) X = ADI where 2/1 = 2 liters of drinking water consumed 0.0187 kg = amount of fish consumed daily F = biomagnification factor ADI = Allowable Daily Intake (mg/day for 70 kg person) For example, consider that the ADI for dimethyl phthalate is 700 mg/day and the biomagnification factor is 130, the above equation can be solved as follows: 2X + (0.0187 x 130)X = 700 2X + (2.43)X = 700 4.43X - 700 X = 158 (or~160 mg/1) Thus, the recommended water quality criterion is 160 mg/1. Similar calculations were made for each of the esters and are presented below: Diethyl 2/1 X + (.0187 x 270)X = 438 2X + 5.05X = 438 7.05X = 438 X = 62 mg/1 (cr*-»60 mg/1) C-68 Iti- ------- Dibutyl 2/1 X + (.0187 x 26) = 12.6 2X + .468X = 12.6 2.468X = 12.6 X = 5.10 mg/1 (or— 5 mg/1) Di-2-ethyhexyl 2/1 X + (.0187 x 95) = 42 2/1 + 1.7765 = 42 3.7765X » 42 X = 11.12 mg/1 (or ^ 10 mg/1) Thus, the recommended water quality criteria for four phthalate esters are: dimethyl 160 mg/1 diethyl 60 mg/1 dibutyl 5 mg/1 di-2-ethylhexyl 10 mg/1 (see Table 11). It seems clear that exposure from the water route pre- sents no real risk to the population in regard to the phthal- ate esters. Reported levels of phthalate esters in U.S. surface waters have only been in the ppb range, at approxi- mately 1 to 2 ug/1 (see Ingestion from Water section). Other routes of exposure such as inhalation (industrial sites manufacturing the esters), dermal exposure, consumption of certain fatty or fatty-like foods and certain fish will be the major contributors to the body-load of phthalate esters. Phthalate ester residues in foods such as margarine, cheese C-69 { \ ;) .'c'7 ------- and milk may, on some occasions, reach 50 ppm. Also a spe- cial group at risk will be patients to whom chronic trans- fusions of blood and blood products are administered. Although it is recognized that routes of exposure other than water contribute more to the body burden of phthalate esters, this information will not be considered in forming ambient water quality criteria until additional analysis can be made. Therefore, the criteria presented assumed a risk estimate based only on ambient water exposure. The need for more accurate determination of residue con- tent of foods, fish and water is still very apparent and, as more data become available, a reevaluation should be made as to the possible hazard to the population by the ingestion of phthalate esters. In summary, based on the use of chronic toxicologic data and uncertainty factors of 100, the criteria levels for phthalate esters have been established. The percent contri- bution of drinking water and of ingesting contaminated fish is given in the following table. Also given are the criteria levels recommended if exposure is assumed to be from fish and shellfish products alone. C-70 ------- Esters Criteria level mq/1 % Contribution of drinking water % Contribution of Fish Products Criteria if Exposure is from Fish Alone mq/1 Dimethyl Diethyl Dibutyl D-2-ethylhexyl 160 60 5 10 45 29 81 53 55 71 19 47 288 87 26 24 o -J ------- REFERENCES Albro, P.W.f et al. 1973. Metabolism of diethhexyll phthal- ate by rats. 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