| Chemical |
Sodium hydroxide |
| CAS-number : |
1310-73-2 |
| |
| Synonyms : |
| aetznatron |
| ascarite |
| caustic soda |
| lye. |
| NAOH |
| Natriumhydroksidi |
| sodalye |
| sodium hydrate |
| |
| Sumformula of the chemical : |
| HNaO |
| |
| Uses : |
Cellulose; rubber manufacturing; intermediate; medicine; rayon
manufacturing; veterinary.
|
| |
| State and appearance : |
White deliquescent solid or solution.
Will dissolve.
|
| |
| Molecular weight : |
40 |
| |
| Spesicif gravity (water=1) : |
| 2.13 |
|
| |
| Vapor pressure, mmHg : |
| 100 |
1111 °C |
| |
| Water solubility, mg/l : |
| 480000 |
25 °C |
| |
| Melting point, °C : |
| 318 |
|
| |
| Boiling point, °C : |
| 1390 |
|
| |
| Other information of degradation : |
Can persist for extended periods of time (Sax 1986).
|
| |
| Other information of bioaccumulation : |
Potential for accumulation: negative (Sax 1986).
|
| |
| LD50 values to mammals in non-oral exposure , mg/kg : |
| 40 |
ipr-mus, Sax 1986 |
| |
| LDLo values to mammals in oral exposure, mg/kg : |
| 500 |
orl-rbt, Sax 1986 |
| |
| Other information of mammals : |
Skin and eye irritation data:
eye, monkey, 1 %, 24 hr, severe;
skin, rabbit, 500 mg, 24 hr, severe;
eye, rabbit 0.4 mg, mild;
eye, rabbit, 1 %, severe;
eye, rabbit, 0.050 mg, 24 hr, severe;
eye, rabbit, 1 mg, 24 hr, severe;
eye, rabbit, 100 mg rinse, severe (Sweet 1987).
|
| |
| Health effects : |
Direct contact: Causes burns and deep ulceration, can destroy
tissue (Sax 1986).
Inhalation of dust may seriously affect lungs.
Ingestion causes
severe tissue damage (Sax 1986).
|
| |
| Mutagenicity : |
cyt-grh-par 20 mg (Sax 1986).
|
| |
| Effects on wastewater treatment : |
Can raise pH and interfere with coagulation (Sax 1986).
|
| |
| LC50 values to crustaceans, mg/l : |
| 33 |
33 - 100, 48hr, Crangon crangon |
| 100 |
* Kemp et al. 1973 |
| |
| LC50 values to fishes, mg/l : |
| 33 |
33 - 100, 48hr, salt water |
| 100 |
starfish, Sax 1986 |
| |
| Other information of water organisms : |
100 mg/l, Daphnia, minnows, lethal;
40 - 240 mg/l, Daphnia magna, toxicity threshold;
125 - 1000 mg/l, various insect larvae, lethal;
25 mg/l, 24hr, brook trout, lethal;
70 mg/l, 5hr, fish, crabs, lethal;
90 mg/l, 4.5hr, oysters, lethal, salt water;
180 mg/l, 23hr, oysters, lethal, salt water (Sax 1986).
|
| |
| Other information : |
The toxicity of sodium hydroxide is based on the increasing
pH-value it induces.
Thus the toxic dose is dependent on the
buffer capacity of the dilution water.
Forms corrosive alkaline solution.
Will precipitate many cations present in water (Sax 1986).
Taste threshold: lower 1 ppm, upper 50 ppm (Sax 1986).
High sodium levels can disperse soils (Sax 1986).
|
References |
| 704 | Kemp, H.T., Little, R.L., Holoman, V.L. & Darby, R.L.
1973.
Water quality data book - Vol. 5.
Effects of
chemicals on aquatic life.
EPA.
Water pollution control
research series 09/73. |
| 2147 | Sax, I. 1986.
Hazardous chemicals information annual No. 1.
Van
Nostrand Reinhold Information Services, New York. 766 s. |
| 2101 | Sweet, D. 1987.
Registry of toxic effects of chemical
substances 1985 - 1986 edition.
U.S.
Department of health and
human services. |
