3-Nitro-1,2,4-triazol-5-one (2014)

2017 ◽  
Vol 34 (1) ◽  
pp. 8-14 ◽  
Keyword(s):  
Reproductive Toxicity ◽  
Liver Microsomes ◽  
Weighted Average ◽  
Exposure Level ◽  
Inhalation Toxicity ◽  
Developmental Studies ◽  
Developmental Defects ◽  
Toxicity Studies ◽  
Time Weighted Average ◽  
Rats And Mice

3-Nitro-1,2,4-triazol-5-one (NTO) is a potential replacement for energetics in military munitions. It is a component of IMX-101, a munition designed to prevent unintentional detonation. This report summarizes the dermal, oral, and inhalation animal toxicity data, including the results of genotoxicity and limited reproductive and developmental studies. NTO has an acute LD50 in rats and mice of >5000 mg/kg, is a potential eye and skin irritant, but does not induce skin sensitization. Acute inhalation toxicity studies in rats were negative, but testicular hypoplasia was observed in a 14-day oral study in rats administered NTO at >500 mg/kg/day. Similar findings were noted in an oral 90-day study at dosages >315 mg/kg/day and in reproductive toxicity studies at >125 mg/kg/day. NTO did not cause any developmental defects. All genotoxicity studies were negative. ADME and pharmacokinetics data showed rapid uptake and elimination of NTO from both inhalation and oral intakes. Biotransformation by liver microsomes demonstrated two separate pathways, one aerobic and the other anaerobic. NTO is not considered an endocrine disruptor. There is very little human data regarding NTO or the IMX-101 mixtures. Using testicular changes in rats as the point of departure for deriving a Workplace Environmental Exposure Level (WEEL) for NTO, the resulting BMDL10 was 40 mg/kg/day, and the 8-hour time-weighted average was 2 mg/m2.

scholarly journals Repeated Noise Exposure Does Not Reach Hazardous Levels During Total Joint Arthroplasty

2020 ◽  
Vol 185 (9-10) ◽  
pp. e1551-e1555
Author(s):  
Sean E Slaven ◽  
Benjamin M Wheatley ◽  
Daniel L Christensen ◽  
Sameer K Saxena ◽  
Robert J McGill
Keyword(s):  
Noise Exposure ◽  
Weighted Average ◽  
Sound Level ◽  
Health Concern ◽  
Exposure Level ◽  
Total Knee ◽  
Time Weighted Average ◽  
Exposure Levels ◽  
Occupational Standards ◽  
Level Meter

Abstract Introduction Noise exposure is an occupational health concern for certain professions, especially military servicemembers and those using power tools on a regular basis. The purpose of this study was to quantify noise exposure during total hip arthroplasty (THA) and total knee arthroplasty (TKA) cases compared to the recommended standard for occupational noise exposure. Materials and Methods A sound level meter was used to record cumulative and peak noise exposure levels in 10 primary THA and 10 primary TKA surgeries, as well as 10 arthroscopy cases as controls. Measurements at the distance of the surgeon were taken in all cases. In TKA cases, measurements were taken at 3 feet and 8 feet from the surgeon, to simulate the position of the anesthetist and circulating nurse, respectively. Results Time-weighted average was significantly higher in THA (64.7 ± 5.2 dB) and TKA (64.5 ± 6.8 dB) as compared to arthroscopic cases (51.1 ± 7.5 dB, P < 0.001) and higher at the distance of the surgeon (64.5 ± 6.8 dB) compared to the anesthetist (52.9 ± 3.8 dB) and the circulating nurse (54.8 ± 11.2 dB, P = 0.006). However, time-weighted average was below the recommended exposure level of 85 dB for all arthroplasty cases. Peak levels did not differ significantly between surgery type or staff role, and no values above the ceiling limit of 140 dB were recorded. Surgeon’s daily noise dose percentage per case was 1.78% for THA and 2.04% for TKA. Conclusion Noise exposure in THA and TKA was higher than arthroscopic cases but did not exceed occupational standards. A daily dose percentage of approximately 2% per case indicates that repeated noise exposure likely does not reach hazardous levels in modern arthroplasty practice.

scholarly journals Differentiating between Testicular Toxicity and Sexual Immaturity in Ortho-phthalaldehyde Inhalation Toxicity Studies in Rats and Mice

2018 ◽  
Vol 46 (7) ◽  
pp. 753-763 ◽  
Author(s):  
Natasha R. Catlin ◽  
Cynthia J. Willson ◽  
Dianne M. Creasy ◽  
Deepa B. Rao ◽  
Grace E. Kissling ◽  
...  
Keyword(s):  
Inhalation Toxicity ◽  
Testicular Toxicity ◽  
Toxicity Studies ◽  
Rats And Mice

scholarly journals Trifluoroiodomethane (CF3I) (2019)

2020 ◽  
Vol 36 (5) ◽  
pp. 310-321
Keyword(s):  
Adverse Effect ◽  
Thyroid Hormone ◽  
Weighted Average ◽  
High Dose ◽  
Exposure Level ◽  
Inhalation Toxicity ◽  
Inhalation Study ◽  
Short Term Exposure ◽  
Adverse Effect Level ◽  
Effect Level

Trifluoroiodomethane (CF3I) is a colorless and odorless gas used primarily as a fire suppressant. CF3I has low acute inhalation toxicity. The no-observed adverse effect level (NOAEL) of CF3I for cardiac sensitization in dogs was 2000 ppm. The potential effects of 4-week inhalation exposure in both rats and mice have been examined. In rats, the NOAEL was 10,000 ppm, and in mice, the NOAEL was 10,000 ppm. In a subchronic inhalation study in rats, the lowest observed adverse effect level (LOAEL) was 20,000 ppm for thyroid-related effects; the study NOAEL (for non-thyroid-related effects) was 20,000 ppm. In a reproductive/developmental inhalation toxicity study in rats, 20,000 ppm CF3I produced minimal general toxicity and no indication of reproductive or developmental toxicity. The LOAEL for parental toxicity (based on thyroid hormone effects) was 2000 ppm; excluding thyroid effects, the parental NOAEL was 7000 ppm CF3I. The observed effects on the thyroid in rats were considered of less relevance to human risk assessment than the other observed systemic effects because of known species-specific differences in sensitivity to thyroid hormone perturbations. There are no chronic toxicity or carcinogenicity studies available. CF3I had mixed results in various in vitro and in vivo genotoxicity assays. The NOAEL of 7000 ppm from the reproductive/developmental inhalation study was used as the point of departure (POD) for workplace environmental exposure level (WEEL) value development. This POD was adjusted to account for interindividual variability, duration of exposure, and database limitations. The resulting 8-h time-weighted average WEEL value of 500 ppm is expected to provide a significant margin of safety against any potential adverse health effects in workers exposed to CF3I. A 15-min short-term exposure limit of 1500 ppm was also established to protect workers from potential cardiac effects produced by acute, high-dose inhalation of CF3I.

scholarly journals Measuring and Mitigating Mercury Gases in the Museums Victoria Collection.

2018 ◽  
Vol 2 ◽  
pp. e27044 ◽  
Author(s):  
Danielle Measday ◽  
Rosemary Goodall
Keyword(s):  
Weighted Average ◽  
Mitigation Strategies ◽  
Hazardous Substances ◽  
Mercury Chloride ◽  
Mercury Vapour ◽  
Exposure Level ◽  
Engineering Controls ◽  
Mercury Compounds ◽  
Scientific Equipment ◽  
Time Weighted Average

For the past six years the conservation and collection management departments at Museums Victoria have been conducting a major survey to determine the type and extent of hazardous substances in the collections to better inform safe handling and storage practices. This paper focuses on mercury compounds in the collection, including mercury chloride applied as a pesticide, mercury sulfide pigments, liquid mercury used in scientific equipment, and mineral specimens such as native mercury and cinnabar. All these compounds can release volatile mercury vapour into storage furniture and have the potential to contaminate both the cabinet and other specimens stored nearby. Although previous testing had confirmed that the air in storage rooms and workspaces contained no detectable levels of mercury vapour, recent publications by Hawks et al. 2004, Havermans et al. 2015 and Marcotte et al. 2017 showing high levels of mercury vapour inside storage containers in herbaria raised concern that there could be higher than acceptable levels of mercury vapour building up inside storage cabinets at Museums Victoria. This prompted analysis of the headspace in cabinets using a Jerome J405 portable mercury vapour meter. Testing was informed by the results of previous hazards surveys using X-ray fluorescence spectrography to target cabinets where mercury vapour was likely to be present. Air from cabinets was sampled across the indigenous cultures, history, technology and natural sciences collections. Results showed levels of mercury vapour could be considerably above 25 μg/m3 the Australian time-weighted average (TWA) exposure standard for an 8 hour workday in cabinets of bird skins and indigenous artefacts treated with mercuric chloride pesticides. Results above 150 μg/m3 the temporary emergency exposure level (TEEL) were measured in the mineralogy collection. Mitigation strategies are being implemented to reduce the risks to staff health and contamination of other collection materials, including enclosing mercury-containing species of minerals in gas barrier film, venting high risk cabinets to dissipate vapour before accessing specimens, and engineering controls during the handling of specimens.

scholarly journals Experimental substantiation for 2-hydroxypropanoic (lactic) acid temporary occupational exposure standard

2021 ◽  
Vol 90 (1) ◽  
pp. 70-74
Author(s):  
VA Turkina ◽  
HV Pryzyhlei ◽  
OI Grushka
Keyword(s):  
Lactic Acid ◽  
Single Dose ◽  
Skin Irritation ◽  
Reproductive Toxicity ◽  
Inhalation Exposure ◽  
Exposure Level ◽  
Inhalation Toxicity ◽  
Toxicology Study ◽  
Workplace Air ◽  
Sensitizing Effect

Lactic (2-hydroxypropanoic) acid is an important metabolic component of living organisms. It is also widely used in various industries. Such a wide application of the acid in manufacturing necessitates the regulation of its content in the workplace air. Toxic effects of lactic acid are described in the literature. It was found that 2-hydroxypropanoic acid belongs to hazard level IV by the criterion of acute oral and inhalation toxicity, it causes skin irritation, severe eye damage, has no skin-resorptive or sensitizing effect, does not cause reproductive toxicity and teratogenicity. Aim of the Research. Substantiation for 2-hydroxypropanoic (lactic) acid indicative safe exposure level (ISEL) in the workplace air. Methods and Materials. Analytical, toxicological, statistical. Results. In the process of conducting toxicology study, it was found that in the conditions of inhalation experiment (intranasal modelling) 2-hydroxypropanoic acid causes changes in the state of the nervous system and affects the cellular composition of bronchoalveolar lavage of experimental animals. Therefore, after a single-dose intranasal instillation Limir = Limac, it can be classified as a substance with non-specific irritant effect. It was found that the threshold of a single-dose inhalation exposure is 20 mg/m3. Conclusions. According to the data obtained in the process of the experiment and data on toxicity parameters and health-based exposure standards of the chemical analogues, the value of ISEL for 2-hydroxypropanoic (lactic) acid in the workplace air was calculated, it is 1.0 mg/m3, aerosol. Key Words: 2-hydroxypropanoic acid, lactic acid, ISEL, workplace air.

scholarly journals Treatment of thoracolumbar burst fractures: extended follow-up of a randomized clinical trial comparing orthosis versus no orthosis

2017 ◽  
Vol 27 (1) ◽  
pp. 42-47 ◽  
Author(s):  
Jennifer C. Urquhart ◽  
Osama A. Alrehaili ◽  
Charles G. Fisher ◽  
Alyssa Fleming ◽  
Parham Rasoulinejad ◽  
...  
Keyword(s):  
Outcome Measures ◽  
Weighted Average ◽  
Average Treatment Effect ◽  
Secondary Outcome ◽  
Thoracolumbar Burst Fractures ◽  
Treatment Comparison ◽  
Average Treatment ◽  
Burst Fractures ◽  
Time Weighted Average

OBJECTIVEA multicenter, prospective, randomized equivalence trial comparing a thoracolumbosacral orthosis (TLSO) to no orthosis (NO) in the treatment of acute AO Type A3 thoracolumbar burst fractures was recently conducted and demonstrated that the two treatments following an otherwise similar management protocol are equivalent at 3 months postinjury. The purpose of the present study was to determine whether there was a difference in long-term clinical and radiographic outcomes between the patients treated with and those treated without a TLSO. Here, the authors present the 5- to 10-year outcomes (mean follow-up 7.9 ± 1.1 years) of the patients at a single site from the original multicenter trial.METHODSBetween July 2002 and January 2009, a total of 96 subjects were enrolled in the primary trial and randomized to two groups: TLSO or NO. Subjects were enrolled if they had an AO Type A3 burst fracture between T-10 and L-3 within the previous 72 hours, kyphotic deformity < 35°, no neurological deficit, and an age of 16–60 years old. The present study represents a subset of those patients: 16 in the TLSO group and 20 in the NO group. The primary outcome measure was the Roland Morris Disability Questionnaire (RMDQ) score at the last 5- to 10-year follow-up. Secondary outcome measures included kyphosis, satisfaction, the Numeric Rating Scale for back pain, and the 12-Item Short-Form Health Survey (SF-12) Mental and Physical Component Summary (MCS and PCS) scores. In the original study, outcome measures were administered at admission and 2 and 6 weeks, 3 and 6 months, and 1 and 2 years after injury; in the present extended follow-up study, the outcome measures were administered 5–10 years postinjury. Treatment comparison between patients in the TLSO group and those in the NO group was performed at the latest available follow-up, and the time-weighted average treatment effect was determined using a mixed-effects model of longitudinal regression for repeated measures averaged over all time periods. Missing data were assumed to be missing at random and were replaced with a set of plausible values derived using a multiple imputation procedure.RESULTSThe RMDQ score at 5–10 years postinjury was 3.6 ± 0.9 (mean ± SE) for the TLSO group and 4.8 ± 1.5 for the NO group (p = 0.486, 95% CI −2.3 to 4.8). Average kyphosis was 18.3° ± 2.2° for the TLSO group and 18.6° ± 3.8° for the NO group (p = 0.934, 95% CI −7.8 to 8.5). No differences were found between the NO and TLSO groups with time-weighted average treatment effects for RMDQ 1.9 (95% CI −1.5 to 5.2), for PCS −2.5 (95% CI −7.9 to 3.0), for MCS −1.2 (95% CI −6.7 to 4.2) and for average pain 0.9 (95% CI −0.5 to 2.2).CONCLUSIONSCompared with patients treated with a TLSO, patients treated using early mobilization without orthosis maintain similar pain relief and improvement in function for 5–10 years.

scholarly journals IMPACT OF GLOBALIZATION UNDER THE ICH GUIDELINES ON THE CONDUCT OF REPRODUCTIVE TOXICITY STUDIES-REPORT ON CURRENT STATUS IN JAPAN, EUROPE AND THE US BY QUESTIONNAIRE SURVEY

2004 ◽  
Vol 29 (3) ◽  
pp. 201-215 ◽  
Author(s):  
Hiroshi MINESHIMA ◽  
Yoshihiko ENDO ◽  
Hiroyuki OGASAWARA ◽  
Keiji NISHIGAKI ◽  
Toshiaki NUMA ◽  
...  
Keyword(s):  
Questionnaire Survey ◽  
Reproductive Toxicity ◽  
Current Status ◽  
Toxicity Studies ◽  
Ich Guidelines ◽  
The Us

Oral (Drinking Water) Two-Generation Reproductive Toxicity Study of Bromodichloromethane (BDCM) in Rats

2002 ◽  
Vol 21 (2) ◽  
pp. 115-146 ◽  
Author(s):  
M. S. Christian ◽  
R. G. York ◽  
A. M. Hoberman ◽  
L. C. Fisher ◽  
W. Ray Brown
Keyword(s):  
Drinking Water ◽  
Reproductive Toxicity ◽  
Clinical Signs ◽  
Sperm Parameters ◽  
Feed Consumption ◽  
Exposure Level ◽  
Organ Weights ◽  
Reduced Body ◽  
Body Weights ◽  
Adult Exposure

Bromodichloromethane (BDCM) was tested for reproductive toxicity in a two-generation study in CRL SD rats. Thirty rats/sex/group/generation were continuously provided BDCM in drinking water at 0 (control carrier, reverse osmosis membrane-processed water), 50, 150, and 450 ppm (0,4.1 to 12.6, 11.6 to 40.2, and 29.5 to 109.0 mg/kg/day, respectively). Adult human intake approximates 0.8 μg/kg/day (0.0008 mg/kg/day). P and F1 rats were observed for general toxicity (viability, clinical signs, water and feed consumption, body weights, organ weights [also three weanling F1 and F2 pups/sex/litter], histopathology [10/sex, 0-and 450-ppm exposure groups]) and reproduction (mating, fertility, abortions, premature deliveries, durations of gestation, litter sizes, sex ratios, viabilities, maternal behaviors, reproductive organ weights [also three weanling F1 and F2 pups/sex/litter], sperm parameters, and implantations. F1 rats were evaluated for age at vaginal patency or preputial separation. Ten P and F1 rats/sex from the 0-and 450-ppm exposure groups and rats at 50 and 150 ppm with reduced fertility were evaluated for histopathology (gross lesions, testes, intact epididymis, all F1 dams for number of primordial follicles). Developmental parameters in offspring included implantation and pup numbers, sexes, viabilities, body weights, gross external alterations, and reproductive parameters (F1 adults). Toxicologically important, statistically significant effects at 150 and/or 450 ppm included mortality and clinical signs associated with reduced absolute and relative water consumption, reduced body weights and weight gains, and reduced absolute and relative feed consumption (P and F1 rats). Significantly reduced body weights at 150 and 450 ppm were associated with reduced organ weights and increased organ weight ratios (% body and/or brain weight). Histopathology did not identify abnormalities. Small delays in sexual maturation (preputial separation, vaginal patency) and more F1 rats with prolonged diestrus were also attributable to severely reduced pup body weights. Mating, fertility, sperm parameters, and primordial ovarian follicular counts were unaffected. The no-observable-adverse-effect level (NOAEL) and the reproductive and developmental NOAELs for BDCM were at least 50 ppm (4.1 to 12.6 mg/kg/day), 5125 to 15,750 times the human adult exposure level, if delayed sexual maturational associated with severely reduced body weights is considered reproductive toxicity. If considered general toxicity, reproductive and developmental NOAELs for BDCM are greater than 450 ppm (29.5 to 109.0 mg/kg/day), or 36,875 to 136,250 times the human adult exposure level. Regardless, these data indicate that BDCM should not be identified as a risk to human reproductive performance or development of human conceptuses.

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