A syringe for use in a drug infusion system , the syringe comprising: a barrel having a front end , a rear end , and a cylindrical wall defining an outer surface and an inner surface , the rear end being open, and the front end including an orifice ; a plunger within the barrel , the plunger including a contact surface at a front end of the plunger , a rear end of the plunger having a tapered outer surface extending between a forward-facing undercut and the rear end of the plunger , a front seal gland extending circumferentially around the plunger , a rear seal gland extending circumferentially around the plunger and axially spaced to the rear of the front seal gland , the rear seal gland adapted to include a rear-facing undercut , a rear seal surface , and the forward-facing undercut , the tapered outer surface increasing in diameter from a surface of the forward-facing undercut to the rear end of the plunger , and a blind bore open at the rear end of the plunger and closed at the front end of the plunger and having a cylindrical portion and a plunger seat on a rear-facing side of a head of the plunger ; a front o-ring made of a diene rubber compound, positioned in the front seal gland , and creating a gas-tight seal between the inner surface of the barrel and the plunger ; wherein a product chamber is defined between the inner surface of the barrel , the front o-ring , and contact surface ; wherein the product chamber is adapted to contain a product to be dispensed by the syringe ; wherein actuation of the plunger within the barrel decreases the volume of the product chamber to dispense the product through the orifice ; and characterized in that : the front o-ring is sized to maintain the gas tight seal through a temperature range of -25°C to 40°C. a barrel having a front end , a rear end , and a cylindrical wall defining an outer surface and an inner surface , the rear end being open, and the front end including an orifice ; a plunger within the barrel , the plunger including a contact surface at a front end of the plunger , a rear end of the plunger having a tapered outer surface extending between a forward-facing undercut and the rear end of the plunger , a front seal gland extending circumferentially around the plunger , a rear seal gland extending circumferentially around the plunger and axially spaced to the rear of the front seal gland , the rear seal gland adapted to include a rear-facing undercut , a rear seal surface , and the forward-facing undercut , the tapered outer surface increasing in diameter from a surface of the forward-facing undercut to the rear end of the plunger , and a blind bore open at the rear end of the plunger and closed at the front end of the plunger and having a cylindrical portion and a plunger seat on a rear-facing side of a head of the plunger ; a front o-ring made of a diene rubber compound, positioned in the front seal gland , and creating a gas-tight seal between the inner surface of the barrel and the plunger ; wherein a product chamber is defined between the inner surface of the barrel , the front o-ring , and contact surface ; wherein the product chamber is adapted to contain a product to be dispensed by the syringe ; wherein actuation of the plunger within the barrel decreases the volume of the product chamber to dispense the product through the orifice ; and characterized in that : the front o-ring is sized to maintain the gas tight seal through a temperature range of -25°C to 40°C. <EOS>