Gas oils (petroleum), hydrotreated light vacuum

Specific investigations: other studies

Description of key information

In several in vitro dermal irritation studies, ET50 values were determined to all be greater than 24 hours.  The photo irritation index for light hydrocracked distillate, light vacuum gas oil, and naval distillate were 0.0, 6.0, and 3.3, respectively.  

Additional information

The Epiderm Model was used to assess the potential toxicity to skin of test articles (ARCO 1994e, Klimisch Score = 2). Cultures exposed to undiluted test articles, for various times were analyzed for their ability to reduce MTT and for the release of PGE2, IL-1alpha, and LDH. The test article induced toxicity was determined by the relative mitochondrial succinate dehydrogenase-mediated reduction of MTT between the test article treated and control treated cultures. The determined ET50 value for the test article is greater than 24 hours. The PGE2 released at the ET50 is 186.0 pg/mL. The IL-1alpha released at the ET50 is 17.6 pg/mL. The LDH released at the ET50 is 3828.0 U/L. The determined ET50 value for the test article is greater than 24 hours. The PGE2 released at the ET50 is 186.0 pg/mL. The IL-1alpha released at the ET50 is 17.6 pg/mL. The LDH released at the ET50 is 3828.0 U/L.

The living skin equivalent test skin bioassay kit was used to assess the toxicity of the test article to a stratified substrate composed of human keratinocytes overlying a layer of human fibroblasts in a collagen matrix (ARCO 1993l, Klimisch Score = 2)

The test article induced toxicity was determined by the relative mitochondrial succinate dehydrogenase-mediated reduction of MTT between the test article treated and control cultures. The ET50 value was determined to be > 24 hours with the highest amount of,-1alpha and PGE2 released among all other substances tested. The LDH released at the ET50 was 96 U/L. The IL-1alpha released at the ET50 was 27.0 pg/mL. The PGE2 released at the ET50 was 1217 pg/mL.

The advanced tissue sciences skin model ZK1300 was used to evaluate the potential toxicity of the test article to human keratinocytes and fibroblasts grown on a nylon mesh (ARCO 1993m, Klimisch score = 2). Direct application of undiluted test articles were tested in a topical application assay. The test article induced toxicity was determined by the relative mitochondrial succinate dehydrogenase-mediated reduction of MTT between the test article treated and control cultures. The exposure time of the test article, required to reduce the amount of MTT reduction in the treated cultures to 50% of that in the control culture was determined (ET50). The amount of PGE2, IL-1alpha and LDH released from the cultures at each exposure time was measured using an ELISA assay and compared to exposure time control and positive control cultures. The ET50 was determined as greater than 24 hours. The PGE2 released at the ET50 was 275 pg/mL. The IL-1alpha released at the ET50 was 146 pg/mL. The LDH released at the ET50 was 10.8 U/L.

In a photo irritation study (Klimisch score = 2, ARCO 1993n), 5 female New Zealand White rabbits were dosed with undiluted test material at 0.3 mL/site, two test sites per animal. Single one hour exposure to test article and 4.8 hour exposure to 10J/cm2 UV A exposure. Observations were made at 30 minutes and 24, 48, and 72 hours post UV A exposure. Based on the 24 and 72 hour scores, the irritation index for the test article is 3.4 for exposed and unexposed skin. The Photo irritation Index is 0.0. Based on the parameters of this study, the test article is a non photoirritant to the skin of albino rabbits.

In a photo irritation study (Klimisch score = 2, ARCO 1993o), 5 female New Zealand White rabbits were dosed with undiluted test material at 0.3 mL/site, two test sites per animal. Single one hour exposure to test article and 4.8 hour exposure to 10J/cm2 UV A exposure. Observations were made at 30 minutes and 24, 48, and 72 hours post UV A exposure.Based on the 24 and 72 hour scores, the irritation index for the test article is 6.4 and 0.4 for exposed and unexposed skin, respectively. The Photo irritation Index is 6.0. Based on the parameters of this study, test article is a severe photo irritatnt to the skin of albino rabbits.

In a photo irritation study (Klimisch score = 2, ARCO 1990e), 5 female New Zealand White rabbits were dosed with undiluted test material at 0.3 mL/site, two test sites per animal. Single one hour exposure to test article and 10J/cm2 UV A exposure (5.6 hours). Observations were made at 30 minutes and 24, 48, and 72 housr post UV A exposure. Based on the 24 and 72 hour scores, the irritation index for the test material is 5.4 and 2.1 for exposed and unexposed skin. The photo irritation index is 3.3. Based on the parameters of this study, the test article is a moderate photo irritant to the skin of albino rabbits.