PEHD. With PP screw cap. Excellent for small scale inter-lab shipping of hazardous samples and chemicals such as corrosives and cleaning compounds. Recommended for customers who are designing, assembling and certifying their own combination packaging. Heavy-duty walls. Designed to resist splitting and puncturing from shipping shocks; proven effective by industrial users. Molded into the bottom: IP2 marking, material, volume, registration notch and Nalgene® brand name. Evaluated at 103 kPa per 49 CFR 173.27 (c) (2), ICAO Technical Instructions Part 3-1;22.214.171.124, and IATA Dangerous Goods Regulations Section 126.96.36.199. Leakproof.