I. Systemic F. H.
Effects H. L.
Gamble Company, Miami Valley Laboratories, Cincinnati, Ohio; Miamiville, Ohio; and Hazleton Laboratories, Falls Church, Received
Hill Top Virginia
Safety evaluation studies of household synthetic detergents were begun prior to the commercial introduction of these products a number of years ago and have continued until the present time. These studies involved acute, subacute, and chronic experiments designed to determine effects of long-term and acute exposure, both orally and topically. They take into consideration not only the intended use of detergents in the daily environment, but also their possible accidental misuse. Current interest in the many aspects of environmental health has prompted the authors to present the results of their toxicologic investigations of two granular, general-purpose household synthetic detergents. Several publications have dealt with specific aspects of the toxicology of complete detergent products (Henderson et al., 19.59; Cann and Verhulst, 1960) and with many of the surfactants that are used in greatest quantity as active ingredients in detergent formulations (Fitzhugh and Nelson, 1948; Food Protection Committee, 1956; Freeman et al., 1945; Heyroth, 1954; Hine et al, 1953; Hopper et al., 1949; Lehman and Draize, 1959; Paynter and Weir, 1960; Research Steering Committee, 1960; Smyth? 1955; Tusing et al., 1960; Woodard and Calvery, 1945). However, the present papers are believed to be the first presentation of a comprehensive investigation of the toxicologic properties of a “complete” household detergent. This report deals with studies on acute and chronic oral toxicity and subacute percutaneous toxicity of the materials tested; the second paper in the series presents data on the effects of the products on the skin and eyes. Granular household detergent products are generally composed of from 10% to 3570 of synthetic surface-active agent (surfactant) of the anionic and/or nonionic type, up to 60% of a complex phosphate “detergency builder,” and 5-10yc of sodium silicate. Most of the remainder of these products is a mixture of simple inorganic salts such as sodium sulfate and sodium chloride, which are by-products of surfactant manufacture, and moisture. In addition each product contains several minor ingredients that impart specific performance characteristics and esthetic properties. The products in the present investigation represent two of the major granular household synthetic detergents in use today. Their formulations were similar, differing only in surfactant and minor ingredient composition. Each consisted of about 20y0 1 Present
anionic surfactant, .50(/i condensed phosphate. 131,; sodium sulfate, and 6’, sodium silicate (SiOZ:Na,0=2: 1) ; the remainin g llI/; was made up 0i moisture and various minor ingredients including perfume, color, and ijuorescent fabric brighteners. The surfactant in detergent type I was sodium alkylbenzene sulfonate: the surfactant in type II was a mixture of approximately equal parts of sodium alkylbenzene sulfonate and sodium alkyl sulfate. METHODS
A&e oral toxicity.” Solutions of the detergent products were administered by stomach tube to white mice and to Sprague-Dawley or Wistar rats from which food had been withheld for 16 hours. Details of body weights, sex, and strain are shown in Table 1. The animals were kept under observation for 2 weeks following treatment. ORAL
1 FOR DETERGENTS
Species and strain
Body weight range c.d
20 ml/kg6 20 ml/kg*
2.7 & 0.2 2.2 ‘- 0.4
3.8 4 0.3 -
Rat, Rat, Rat,
Wistar Wistar’ Sprague-Dawley
200-2.50 zoo-220 200-250
20 ml/kgb 50% (w/w) 50% (w/w)
2.7 2 0.1 3.2 4 0.1 -
4.4 4 0.1 6.8 4 0.1 7.5 4 1.0
4.6 -c- 0.4
5.0 2 0.4
Q Includes 95% confidence limits (1.96 5). b Dose was administered as a constant volume c Male rats; equal numbers of male and female
aqueous solution per kilogram animals were used in the other
7.1 5.8 7.1
of body weight. determinations.
LD50 values were calculated by the method of Litchfield and Wilcoxon (1949) or that of Miller and Tainter (1944). Emetic dose.3 Aqueous slurries of the detergents were administered by stomach tube to adult male and female mongrel dogs from which food had been withheld overnight. Single graded doseswere given in increasing amounts until a dose was reached which induced emesisin all the dogs in a test group of four. In addition, dogs were given 5 g/kg dosesof the detergents in order to determine whether emesisor toxic effects would occur at such a large dose. Chronic oral toxicity.J Weanling albino rats of the Carworth Farms strain were selected at random and housed individually in wire-mesh cages elevated above the droppings. Complete blood counts were taken on representative animals at the start of the experiment to assurethe existence of a healthy colony. Groups of 40 male and 40 female rats were assignedto the following groups: (1) Control, stock diet; (2) detergent type I, 0.5% in stock diet; (3) detergent type II, 0.5% in stock diet. 2 This work was done at Hill Top Research Institute, Inc., and 3 These studies were carried out at Hill Top Research Institute, 4 This program was conducted at Hazleton Laboratories.
at Miami Inc.
Purina Laboratory Chow was the stock diet; this ration and tap water were offered ad libitum. At the beginning of the study, twenty animals of each sex were designated for use in blood and urine studies and for grossand microscopic pathologic examination. Ten rats of each sex were scheduled to be killed after 26 weeks, and ten after 52 weeks. Only those originally designated were sacrificed at the indicated times. The remaining rats were fed the designateddiets for a total of 104 weeks. Body weights and food and water consumption of individual rats were recorded at weekly intervals, and regular observations were made as to general appearance,condition, and behavior of each animal. Whenever possible, animals that died durin g the course of the experiment were autopsied, gross pathology was recorded, and representative tissues were preserved in formalin for microscopic examination. All animals sacrificed at 26 and 52 weeks and all rats surviving for 104weekswere killed by cervical fracture and exsanguination, and grossautopsieswere performed. The liver, kidneys, full cecum (except from rats sacrificed at 26 weeks) and empty cecum were weighed, and organ-to-body weight ratios were computed. Thyroid, liver, kidney, adrenal, urinary bladder, small intestine, large intestine, cecum, and bone marrow from three to five animals per group, of each sex, were preserved for microscopic examination. Examination was also made of any unusual lesionsfound at autopsy. Complete blood counts, blood urea nitrogen and icterus index determinations, and urine analyses were conducted on representative rats of each sex, from each group, at each interval of sacrifice. Subacute percutaneous toxicity.3 The procedure used for the study of percutaneous toxicity was essentially that described by Draize (1959) for his go-day test. The solutions were applied to the clipped skin of rabbits, 5 days a week for 13 weeks. Animals were weighed weekly, and red cell counts, hemoglobin determinations, and differential leucocyte counts were carried out at the beginning and end of the test. Tissueswere examined both grossly and microscopically at the end of the experimental period. Three experiments of this kind have been run with detergent type II, using a 7.5% solution and a daily doseof 2 ml/kg; 23 rabbits were used in three tests. In a single study on 7 rabbits with detergent type I, the daily dose was 1 ml of a 10% solution per kilogram body weight. RESULTS
Acute Oral Toxicity The LDSo values given in Table 1 are representative of a larger number of data collected over a period of years. Under comparable conditions of determination, LDSO values with rats for detergent type II ranged from one and one-half to two times those for type I. For type II, concentration of dosehad a marked effect, toxicity decreasing with increasing concentrations in water. The two detergents did not differ in their toxicity to mice. The two detergents were in the same range of oral toxicity as table salt (LDB,, = 3.1 g/kg) and sodium bicarbonate (LD60 = 4.3 g/kg), as determined with SpragueDawley rats in our laboratory,
Emetic Dose As shown in Table 2, both detergents elicited prompt emetic response in dogs at a dose of 0.40 g/kg. At lower doses, emesis also tended to be quite prompt when it occurred. In no case was there protracted emesis; usually each dog vomited once and then showed no further signs of distress. The appearance of the vomitus was frothy, but was otherwise unremarkable; there were no signs of blood in the vomitus. even TABLE EMETIC
Time for emesis to occur (minutes)
Dose Detergent Type
1. 1, 5,6 1. 1
2 of4 3of4
4, 5, 8, 2,3,4,-
as a 50%
0.20 0.40 a Administered
1. 1. I,1
in the case of six dogs given 5 g/kg of detergent. After the showed normal appetite and weight retention and exhibited no dog which received 5 g/kg of detergent type II had some slight on the third day after dosing, but this appeared to be unrelated
experiments the dogs signs of toxicity. One diarrhea which began to treatment.
Chronic Oral Toxicity Regular examination of the animals revealed no differences between experimental and control animals in general appearance or behavior. Table 3 presents quantitative data on all groups. Although there was a certain amount of fluctuation, growth rates for all groups are comparable; similarly. little variation is seen in the figures for food consumption. “Per cent survival” was calculated by dividing the “actual rat days” (total number of days that all the rats in a given group lived) by the “theoretical rat days” (assuming 100% survival for the entire period) and multiplying by 100. Survival for all groups was within normal limits. The results of clinical laboratory studies revealed no significant alterations in hemoglobin, icterus index, red and white cell counts, differential counts, blood urea nitrogen, or urine analysis in the experimental animals as compared to the controls. As indicated by asterisks in Table 3, there were a few cases in which the ratio of organ:body weight for the experimental group differed significantly (P = 0.05) from the control value. Since there was no microscopic evidence of tissue damage, and since the deviations did not occur consistently with respect to time, these differences are not considered to be biologically important.
Weeks: 10-18 rats/group)
Mean food % Survival
Number of rats per group, Mean body weight (g):
0.69 2.17 0.45
396 450 463
(fi = 0.05).
Liver Kidney Cecum, Cecum,
Liver Kidney Cecum, Cecum,
52 Weeks Weeks
3.03 0.71 1.75*
8 F3 g
There was no indication that tumors or other signs of pathology, gross or microscopic, occured more frequently in any of the experimental groups than in the controls. The types of tumors encountered were varied and consisted mostly of incidental findings common to old-age rats of this strain (Treon et al., 1953; Saxton, 1941). The findings are summarized in Table 4. TABLE INCIDENCE
Control animals Males:
104-WEEK-OLD OF THE
1 adenocarcinoma of the liver with metastasis to the lung 1 spermatocele of the testis 1 adenocarcinoma involving small and large intestine *(82 weeks)
1 1 1 1 3 1
desmofibromatosis of the adrenal benign adenoma of the ovary chromophobe adenoma of the pituitary papillary cystadenoma of the breast cystic disease of the breast subcutaneous lymphosarcoma 1 benign adenoma of the pancreas 1 subcutaneous fibrosarcoma * (80 weeks)
Type 1 Males:
FemaIes: Type II Males :
1 cystic disease 1 chromophobe
of the breast adenoma of the pituitary
1 benign nodular hyperplasia of the lung 1 pheochromocytoma of the adrenal 1 malignant lymphoma of the lung
1 1 1 2 1
chromophobe adenoma of the pituitary squamous cell carcinoma of the bladder Hiirthle-cell adenoma of the thyroid cystic disease of the breast subcutaneous fibroma
Subacute Percutaneous Toxicity There were no systemic changesattributable to treatment, and only minimal effects were seenin the skin, despite the severity of treatment. DISCUSSION The acute oral LDbO to rats and mice, as reported for the two detergents described here is, of course, only one consideration in an assessmentof their acute ingestion hazard (Carter and Griffith, 1961). Their pronounced emetic properties, which are not manifest in rodent species,are consideredto be an important safeguard in reducing the likelihood of toxic effects on accidental ingestion by humans. For both the detergents, the minimum emetic dose was an order of magnitude less than the oral LD;,o
oral doses in the range of the rat
toxic effects in dogs. Still another factor to be consideredis the light, fluffy consistency of these granular
products which would serve to limit the quantity which could be ingested (Hodge and Downs, 1961). The detergents in this study had bulk densities of 0.38 g/cc (type I) and 0.32 g/cc (type II). For this reason the LD 50 values in Table 1 are expressed in cc/kg as well as in the more conventional units of g/kg. By direct extrapolation on the basis of body weight, it is obvious that the volume of a toxic dose of either detergent for a child or adult human would be a rather large quantity. It seems unlikely that such a quantity of detergent granules could be ingested, especially in view of the fact that the volume of a swallow is only 0.33 cc/kg for small children and 0.23-0.26 cc,/kg for adults (Jones and Work, 1961). The administered doses in the two-year feedin g study and the go-day topical application studies reported here provide safety factors of many times the levels of detergents which might conceivably enter the body from residues on dishes, cooking utensils, and the skin. For example, the 0.57~ level of detergents in the diet fed in this study represents an intake at least one thousand times that which might be picked up from the residue on unrinsed dishes (Committee on Synthetic Detergents, 1956). Taken together, the findings of no toxic symptoms in these studies are assurance that there would be no toxic hazard from contact with these detergents in the daily environment. SUMMARY Investigations of systemic toxicity have been carried out on two representative household synthetic detergents formulated from anionic surfactants, sodium tripolyphosphate, sodium sulfate, and sodium silicate. LD,, values, measured by oral administration to mice and rats, ranged from 2.2 to 4.6 g/kg for a detergent containing alkylbenzene sulfonate as the surfactant, and from 3.8 to 7.5 g/kg for a detergent containing a mixture of alkylbenzene sulfonate and alkyl sulfate as the surfactant. Oral doses of 0.4 g/kg of either detergent caused prompt, uncomplicated emesis in dogs, with no evidence of toxicity from doses as high as 5 g/kg. Rats consumed diets containing 0.5% of the products for two years without toxic manifestations. There was no evidence of systemic effects when 7.5% solutions of the products were applied to the clipped skin of rabbits at a level of 2 ml/kg/day for 90 days. Results standpoint
of this evaluation show that the two products tested are relatively of systemic effects. This conclusion is supported by a long history
innocuous from of safe use.
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