Final Report on the Safety Assessment of Polyethylene1

Abstract

Polyethylene is an ethylene polymer used for a variety of purposes in cosmetics as an abrasive, adhesive, binder or bulking agent, an emulsion stabilizer, a film former, an oral care agent, and as a nonaqueous viscosity-increasing agent. Polyethylene is also used in food packaging materials and medical products, including prosthetics. The molecular weight of Polyethylene as used in cosmetics varies over a wide range. The lowest reported molecular weight is 198 Daltons and the highest is 150,000. In any given polymer preparation, there can be a broad range of molecular weights. Cellular and tissue responses to Polyethylene, determined as part of implant biocompatibility testing, include fibrous connective tissue build-up around the implant material that varies as a function of the physical form of the implant material. Specific assays for osteoblast proliferation and collagen synthesis demonstrated a reduction as a function of exposure to Polyethylene particles that is inversely related to particle size. The effect of Polyurethane particles on monocyte-derived macrophages, however, had a stimulatory effect, prolonging the survival of these cells in culture. The LD50 for Polyethylene, with an average molecular weight of 450, in rats was > 2000 mg/kg. For Polyethylene with an average molecular weight of 655, the LD50 was > 5.0 g/kg. Toxicity testing in rats shows no adverse effects at Polyethylene (molecular weight not given) doses of 7.95 g/kg or at 1.25%, 2.50%, or 5.00% in feed for 90 days. Dermal irritation studies on rabbits in which 0.5 g of Polyethylene (average molecular weight of 450) was administered in 0.5 ml of water caused no irritation or corrosive effects; Polyethylene with an average molecular weight of 655 was a mild irritant. Polyethylene (average molecular weight of 450) did not cause dermal sensitization in guinea pigs tested with 50% Polyethylene (w/w) in arachis oil BP. Polyethylene, with a molecular weight of 450 and a molecular weight of 655, was a mild irritant when tested as a solid material in the eyes of rabbits. Rabbit eyes treated with a solution containing 13% Polyethylene beads produced minimal irritation and no corneal abrasions. No genotoxicity was found in bacterial assays. No chemical carcinogenicity has been seen in implantation studies, although particles from Polyethylene implants can induce so-called solid-state carcinogenicity, which is a physical reaction to an implanted material. Occupational case reports of ocular irritation and systemic sclerosis in workers exposed to Polyethylene have been difficult to interpret because such workers are also exposed to other irritants. Clinical testing of intrauterine devices made of Polyethylene failed to conclusively identify statistically significant adverse effects, although squamous metaplasia was observed. The Cosmetic Ingredient Review (CIR) Expert Panel did not expect significant dermal absorption and systemic exposure to large Polyethylene polymers used in cosmetics. The Panel was concerned that information on impurities, includ...

Alternatives for Conventional Alkane Solvents

“…PAOs in contrast are nonvolatile and do not have inhalation toxicity due to their low vapor pressure. They also have low oral toxicity. , Finally, unlike alkanes PAOs are physically recyclable by a gravity separation as discussed below.…”

“…However, oligomeric hydrocarbon solvents have some significant advantages over their low molecular weight alkane analogs. First, they are nonvolatile and relatively nontoxic. , Second, unlike lower molecular weight alkanes, they do not significantly contaminate polar phases when used in conjunction with polar solvents. This is true when the nonpolar and polar solvents are separated by a liquid/liquid separation after heating an initial biphasic mixture to form a single phase and then cooling to reform the biphasic mixture (a thermomorphic process) .…”

Impact of polyvinyl chloride, polystyrene, and polyethylene on the organism of mice

“…Particles of polysterene are the most common types of plastic pollution in oceans, and combined with polyethylene films, plastic bags and containers for food products make up the largest part of oceanic debris (Knight, 2012). According to assessments made in 2014, 268,940 tons of plastic are present on the ocean surface, and the total amount of separate fragments of plastic waste equal 5.25 trillions (Eriksen et al, 2014). Over 400 thou-sand marine mammals die every year as a result of plastic pollution in the ocean.…”