a plasticized hsbc blended with polypropylene and free of a filler material which adversely affects clarity , provides an injection - moldable composition for an article required to have specific properties , namely , tensile strength in the range from about 4 . 13 to 8 . 96 mpa ; tear strength in the range from about 21 to 52 . 6 n / mm ; softness in the range from about 45 but less than 65 shore a ; and haze less than 20 %, measured by astm d1003 using a byk gardner micro tri - gloss 4525 meter ; and it is essential that all of these properties , along with the physical dimensions of the molded article , remain substantially unchanged after immersion of the article in boiling water for 1 hour . such a composition is may be injection molded to form a nipple for feeding an infant , or a teething ring , or goggles for a diver , and the articles are sterilizable and recyclable .