Permeation of 4-Cyanophenol and Methyl Paraben from Powder and Saturated Aqueous Solution through Silicone Rubber Membranes and Human Skin

2006 ◽  
Vol 95 (11) ◽  
pp. 2526-2533 ◽  
Author(s):  
Wayne J. Romonchuk ◽  
Annette L. Bunge
Keyword(s):  
Aqueous Solution ◽  
Human Skin ◽  
Silicone Rubber ◽  
Saturated Aqueous Solution ◽  
Methyl Paraben

Darstellung und röntgenographische Untersuchung von drei Strontiumazidhydraten

1973 ◽  
Vol 137 (4) ◽  
Author(s):  
H. Krischner ◽  
H. E. Roth
Keyword(s):  
Aqueous Solution ◽  
Saturated Aqueous Solution

AbstractThree different hydrates of strontiumazide have been prepared by crystallization from saturated aqueous solution. Sr(N

Final Report on the Safety Assessment of Potassium Silicate, Sodium Metasilicate, and Sodium Silicate1

2005 ◽  
Vol 24 (1_suppl) ◽  
pp. 103-117 ◽  
Keyword(s):  
Aqueous Solution ◽  
Human Skin ◽  
Sodium Silicate ◽  
Safety Assessment ◽  
Sodium Metasilicate ◽  
Potassium Silicate ◽  
Female Rats ◽  
Male Rats ◽  
Molar Ratio ◽  
Eye Irritation

Potassium Silicate, Sodium Metasilicate, and Sodium Silicate combine metal cations with silica to form inorganic salts used as corrosion inhibitors in cosmetics. Sodium Metasilicate also functions as a chelating agent and Sodium Silicate as a buffering and pH adjuster. Sodium Metasilicate is currently used in 168 formulations at concentrations ranging from 13% to 18%. Sodium Silicate is currently used in 24 formulations at concentrations ranging from 0.3% to 55%. Potassium Silicate and Sodium Silicate have been reported as being used in industrial cleaners and detergents. Sodium Metasilicate is a GRAS (generally regarded as safe) food ingredient. Aqueous solutions of Sodium Silicate species are a part of a chemical continuum of silicates based on an equilibrium of alkali, water, and silica. pH determines the solubility of silica and, together with concentration, determines the degree of polymerization. Sodium Silicate administered orally is readily absorbed from the alimentary canal and excreted in the urine. The toxicity of these silicates has been related to the molar ratio of SiO2/Na2O and the concentration being used. The Sodium Metasilicate acute oral LD50 ranged from 847 mg/kg in male rats to 1349.3 mg/kg in female rats and from 770 mg/kg in female mice to 820 mg/kg in male mice. Gross lesions of variable severity were found in the oral cavity, pharynx, esophagus, stomach, larynx, lungs, and kidneys of dogs receiving 0.25 g/kg or more of a commercial detergent containing Sodium Metasilicate; similar lesions were also seen in pigs administered the same detergent and dose. Male rats orally administered 464 mg/kg of a 20% solution containing either 2.0 or 2.4 to 1.0 ratio of sodium oxide showed no signs of toxicity, whereas doses of 1000 and 2150 mg/kg produced gasping, dypsnea, and acute depression. Dogs fed 2.4 g/kg/day of Sodium Silicate for 4 weeks had gross renal lesions but no impairment of renal function. Dermal irritation of Potassium Silicate, Sodium Metasilicate, and Sodium Silicate ranged from negligible to severe, depending on the species tested and the molar ratio and concentration tested. Sodium Metasilicate was negative in the local lymph node assay (LLNA), but a delayed-type hypersensitivity response was observed in mice. Potassium Silicate was nonirritating in two acute eye irritation studies in rabbits. Sodium Metasilicate (42.4% H20) was corrosive to the rabbit eye. Sodium Silicate was a severe eye irritant in some eye irritation studies, but was irritating or nonirritating in others. A skin freshener containing Sodium Silicate was nonirritating. Sodium Metasilicate was nonmutagenic in bacterial cells. Rats given Sodium Silicate (600 and 1200 ppm of added silica) in the drinking water in reproductive studies produced a reduced number of offspring: to 67% of controls at 600 ppm and to 80% of controls at 1200 ppm. Three adult rats injected intratesticularly and subcutaneously with 0.8 mM/kg of Sodium Silicate showed no morphological changes in the testes and no effect on the residual spermatozoa in the ductus deferens. Sodium Metasilicate (37% in a detergent) mixed with water was a severe skin irritant when tested on intact and abraded human skin, but 6%, 7%, and 13% Sodium Silicate were negligible skin irritants to intact and abraded human skin. Sodium Silicate (10% of a 40% aqueous solution) was negative in a repeat-insult predictive patch test in humans. The same aqueous solution of Sodium Silicate was considered a mild irritant under normal use conditions in a study of cumulative irritant properties. The Cosmetic Ingredient Review (CIR) Expert Panel recognized the irritation potential of these ingredients, especially in leave-on products. However, because these ingredients have limited dermal absorption and Sodium Metasilicate is a GRAS direct food substance, the Panel deemed the ingredients safe for use in cosmetic products in the practices of use and concentration described in this safety assessment, when formulated to avoid irritation.

scholarly journals Exploring User Perception Challenges in Vibrotactile Haptic Display Using Resonant Microbeams under Contact with Skin

2019 ◽  
Vol 3 (2) ◽  
pp. 38
Author(s):  
Daehan Wi ◽  
Angela A. Sodemann
Keyword(s):  
Human Skin ◽  
Silicone Rubber ◽  
Force Measurement ◽  
Tactile Display ◽  
User Perception ◽  
Primary Metal ◽  
Beam Vibration ◽  
Skin Contact ◽  
Five Phases ◽  
Contact Experiments

Resonant vibrotactile microbeams use the concept of resonance to excite the vibration of cantilever beams, which correspond to pixels of an image. The primary benefit of this type of tactile display is its potential for high resolution. This paper presents the concept of the proposed system and human skin contact experiments to explore user perception challenges related to beam vibration during skin contact. The human skin contact experiments can be described in five phases: dried skin contact to metal beam tips, wet and soaped skin contact to metal beam tips, skin contact with a constraint, normal force measurement, and skin contact to the tips of silicone rubber beams attached to metal beam tips. Experimental results are analyzed to determine in what cases of skin contact the beams stop vibrating. It is found that the addition of silicone rubber beams allows the primary metal beams to continue vibrating while in contact with skin. Thus, the vibration response of a metal beam with silicone rubber beams is investigated for the better understanding of the effect of silicone rubber beams on the metal beam vibration.

Observations on the effect of hexoestrol on earthworms and other soil invertebrates

1960 ◽  
Vol 55 (2) ◽  
pp. 189-190 ◽  
Author(s):  
F. Raw
Keyword(s):  
Aqueous Solution ◽  
Soil Fauna ◽  
Lumbricus Terrestris ◽  
Soil Invertebrates ◽  
Saturated Aqueous Solution ◽  
Egg Capsules ◽  
Allolobophora Caliginosa

1. Activity of Lumbricus terrestris, Allolobophora caliginosa and A. chlorotica was unaffected by 15 mg. hexoestrol in solution in 500 g. soil.2. Activity and reproduction of A. caliginosa was unaffected by 10 mg. hexoestrol in 500 g. soil, but 100 mg. and over affected activity and stopped reproduction.3. Egg capsules of A. caliginosa and A. chlorotica developed normally in a saturated aqueous solution of hexoestrol.4. No effect on the soil fauna of grass plots due to grazing with implanted bullocks was observed.

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