Occupational exposure to DL-lactone is expected to be low, as the substance is used as an intermediate in a closed process. Exposure mainly occurs through completion of process sampling and potentially during drumming-off operations (COSHH assessment).
In view of the use of the substance consumer exposure is not anticipated.
HUMAN HEALTH HAZARDS
Effects on Human Health
Toxicokinetics, Metabolism and Distribution
No data available.
The acute toxicity of DL-lactone was investigated in rats and mice.
Studies in Animals
The oral LD50 in rats and mice was 9700 and 4380 mg/kg bw, respectively. No information on clinical symptoms, body weight or macroscopy was available from these studies. Animals were observed for a total of 10 days (Bächtold, 1976).
In the range finding test for a micronucleus test in mice (Meerts, 2002) 2000 mg/kg bw dosed orally caused 4 of 8 animals to die within 1.5 hours. At 1500 mg/kg bw no mortality was found. No LD50 can be drawn from this study. Clinical signs were reported for all animals treated with 2000 mg/kg bw. Within 1.5 hours, all animals showed lethargy or convulsions, one animal had tremors. Lethargy and rough coat was also observed within 1.5 hours after treatment with 1500 mg/kg bw. At both doses the survivors showed no abnormalities anymore after 2 and 3 days.
Studies in Humans No data available. Conclusion The LD50 of DL-lactone via the oral route is > 2000 mg/kg bw.
3.1.3 Irritation Skin Irritation Studies in Animals
DL-lactone was not irritating to the skin of rabbits after 4 hours exposure under semi-occlusion (according to OECD 404). No symptoms of systemic toxicity were observed during the 72-hours treatment period (Teunissen, 2005a).