2. Effects on Humans: Methacrylic acid can affect the eyes, skin, and immune system in humans [ACGIH 1991]. Exposure to methacrylic acid vapor may produce skin and eye irritation [Patnaik 1992]. In a case study involving 37 acrylic acid resin workers, methacrylic acid caused sensitization in a few of the workers and thus appears to be a sensitizing agent [ACGIH 1991]. Skin toxicity and a severe corneal burn were observed in a population of workers exposed to up to 113 ppm methacrylic acid [ACGIH 1991].