George H. Y. Lin

Acute Toxicity Studies of Xerox Reprographic Toners

Typical reprographic toners consist of a thermoplastic polymer or polymers as the major component, a colorant or colorants (carbon black or color pigments), and small quantities of additives such as charge control and/or lubricating/release agents. Another type of toner contains iron oxides and polymers) as the major components. As a complement to the recently published Xerox chronic inhalation studies of toners, we are reporting the acute toxicity studies of some typical Xerox toners. The studies include acute oral toxicity in rats, acute dermal toxicity in rabbits, acute inhalation toxicity in rats, eye irritation in rabbits, skin irritation in rabbits, skin sensitization in guinea pigs, and the repeated-insult patch test in humans. These studies represent our acute toxicity testing using different protocols with various toners carried out during the period 1969–1984. In addition, we recently carried out acute dermal toxicity testing at 5 g/kg with two representative toners, for the purpose of classification of waste toners in the State of California. The test results consistently indicate that all toners were practically nontoxic: oral LD50 from <5 to <35 g/kg; dermal LD50 from <2 to <5 g/kg; and inhalation LC50 (4 h) from <0.17 to <10.2 g/m3. They were nonirritating to the eye and nonirritating/ nonsensitizing to the skin.

Toxicological Studies of a Representative Xerox Reprographic Toner

Typical Xerox reprographic toners consist of a thermoplastic polymer as the major component, a colorant (carbon black or color pigment), and low quantities of additives such as charge control and/or lubricating agents. Another type of Xerox toner contains iron oxides and a polymer as the major components. Among all toners marketed by Xerox Corporation, the original 1075 toner (being discontinued and reformulated) was a major safety concern, because it contained approximately 2% cetylpyridinium chloride (CPC) as a charge control agent. CPC by itself is very toxic and causes severe irritation to the eye and skin. Although CPC has been used in very low concentrations in consumer products such as mouthwash, it was unknown whether a 50-fold dilution of CPC in the toner formulation would represent any safety issue. Therefore, a series of toxicological testing on the original 1075 toner was conducted. The test results indicate that the original Xerox 1075 toner was practically nontoxic following acute oral, dermal, and inhalation exposures; nonirritating to the eye; nonir-ritating/nonsensitizing to the skin; nonmutagenic in a battery of short-term assays (Ames Salmnonella/microsome assay, mouse lym-phoma assay, in vitro sister chromatid exchange assay in Chinese hamster ovarian cells, and in vitro BALB/3T3 cell transformation assay); and nonteratogenic in rats when inhaling the toner dust up to 1.2 g/m3. In addition, no mutagenic responses were observed from testing the urine or feces (by Ames test) and bone marrow (by examining micronucleus formation) of rats exposed to the toner dust at 1.3 g/m3 at the end of a subchronic inhalation study. Because all Xerox toners are alike, the toxicology of the original Xerox 1075 toner was considered a “worst-case” situation, relative to health and safety. However, it did not appear to represent any health and safety issue. The results of this study, together with the fact that no evidence of carcinogenicity was found in the Xerox chronic inhalation study on toner, indicate that Xerox toners are not safety hazards, with respect to the end points indicated in this report.

Acute Toxicity Studies with C. I. Pigment Red 122

Test and Results: Oral Toxicity Protocol: Three doses (10.3, 15.4, and 23.1g/kg) of the test article (40% w/vaqueous suspension) were administered br. gavage to selected healthy Sprague-Dawley albino rats, 4 (2M, 2F) at each dose leve. The body weights of the test animals were 161 to 183 g after fasting 16hrs. Animals were observed for mortality and clinical signs twice daily for 14 days after dosing. Body weights were recorded on Days 0, 7 and 14. Necropsy examinations of all animals were carried out at the end of Day 14. Results: No mortality was observed at all dose levels (LDso>23.1 g/kg). Abnormal clinical signs observed in all dose groups included hyperactivity, ruffed fur, diarrhea, and magenta feceswithin 2 hrs followinq administration but appeared normal on the following day. Necropsy examination of all animals at sacrifice revealed no gross pathologic alterations. Body weight gains were within normal range of growth.

Acute Toxicity Studies with Copper Tetra-4-(Octadecylsulphonamide)-Phthalocyanine

Test and Results: Oral Toxicity Protocol: Three doses (10.3, 15.4, and 23.1 g/kg) of the test article (40% wlv aqueous suspension) were administered by gavage to Sprague-Dawley albino rats, weighing 161 to 194 g after fasting. Four animals (2M, 2F) were used in each dose group. Animals were observed for mortality and clinical signs twice daily for 14 days after dosing. Body weights were recorded on Days0, 7 and 14. Necropsy examinations of all animals were carried out at the end of Day 14. Results: No mortality was observed at all dose levels (LDso>23.1 g/kg). Abnormal clinical signs included hypoactivity, ruffed fur, diarrhea, and blue feces in all groups during Day 1 but appeared normal on the following day. Necropsy examination of all animals at sacrifice revealed no gross pathologic alterations. Body weight gains were within normal range of growth.

Acute Toxicity Studies with C. I. Pigment Yellow 97

Test and Results: Oral Toxicity Protocol: Three doses (10.3, 15.4, and 23.1 g/kg) of the test article (40% wlv aqueous suspension) was administered by gavage to Sprague-Dawley albino rats, 4 animals (2M, 2F) at each dose level. The body weights of the test animals were 160 to 185 g after fasting. Animals were observed for mortality and clinical signs twice daily for 14 days after dosing. Body weights were recorded on Days 0, 7 and 14. Necropsy examinations of all animals were carried out at the end of Day 14. Results: No mortality was observed at all dose levels (LDso>23.1 g/kg). Abnormal clinical signs observed in all dose groups included hyperactivity, ruffed fur, diarrhea, and yellow feces within 2 hrs following administration but appeared normal on the following day. Necropsy examination of all animals at sacrifice revealed no gross pathologic alterations. Body weight gains were within normal range of growth.

Acute Toxicity Studies with 9-Ethenyl-9H-Carbazole Homopolymer

Oral Toxicity Protocol: One single dose (5 g/kg) of the test article (25% w/v suspension in propylene glycol) was administered by gavage to 10 Sprague-Dawley albino rats (5M, SF), weighing 170 to 240 g after fasting. Animals were observed for mortality and clinical signs twice daily for 14 days after dosing. Body weights were recorded on Days 0, 7 and 14. Necropsy examinations of all animals were carried out at the end of Day 14. Results: No mortality was observed at 5 g/kg. Abnormal clinical signs included staggering gait, low body posture, lacrimation, weakness, crusty nose, and irregular breathing within 5 hrs following administration but appeared normal on the following day. Gross necropsy revealed enlarged, solitary cervical lymph nodes and multiple, red, focal depressions of the lung in 2 males and a diaphragmatic hernia of the liver in one female. Body weight gains were within normal range of growth.