Cysteine is a non-essential amino acid that can be synthesized by the human body under normal physiological conditions if a sufficient quantity of methionine is available. Cysteine is commonly used as a precursor in the food and pharmaceutical industries. Cysteine is used as a processing aid for baking, as an additive in cigarettes, as well as in the preparation of meat flavours.

CAS：3374-22-9
中文别名：2-氨基-3-巯基丙酸;DL-丰胱胺酸;3-巯基-DL-丙氨酸;DL-2-氨基-3-巯基丙酸;(±)-2-氨基-3-巯基丙酸;
英文别名：2-amino-3-sulfanylpropanoic acid;2-Amino-3-mercaptopropionic acid;2-Amino-3-mercaptopropionicacid;EINECS 222-160-2;2-Amino-3-mercaptopropanoic acid;DL-Cysteine;2-amino-3-sulfopropionic acid;
分子式：C3H7NO2S
分子量：121.158
精确质量：121.02
Psa：102.12
Logp：0.0284

MDL号：MFCD00004881
EINECS号：222-160-2

外观与性状：白色固体
密度：1.334 g/cm3
沸点：293.9ºC at 760 mmHg
熔点：225ºC (dec.)
闪点：131.5ºC
折射率：1.549
稳定性：Stable. Incompatible with strong oxidizing agents,
储存条件：Store in a tightly closed container. Store in a cool, dry, well-ventilated area away from incompatible substances. Refrigerator (approx 4ºC).

安全说明：S26; S36/37/39
危险类别码：R20/21/22
海关编码：2930909090
危险品标志：Xn; Xi
危险性描述：H302; H314; H335
危险标志：GHS05, GHS07
信号词：Danger
危险性防范说明：P280; P301 + P312 + P330; P303 + P361 + P353; P304 + P340 + P310; P305 + P351 + P338