Black Liquor

Signal word

DANGER Black Liquor - CAS# 66071-92-9 GHS Classification/Category

Hazard pictograms

HEALTH Skin Corrosion/Irritation- Causes Severe Skin Burns and Category 1 Eye Damage Eye Damage/Irritation- Category 1 Causes Serious Eye Damage Acute Toxicity Oral- category 3* Toxic If Swallowed Specific Target Organ Toxicity (STOT) May Cause Damage to the Single Exposure Respiratory System Respiratory- Category 1B 2. Hazard Identification (cont’d.) GHS Classification/Category Skin Sensitization- May Cause an Allergic Skin Category- 1B Reaction * NOTE: Acute toxicity determinations have not been made for black liquor as a product (CAS # 66071- 92-9) due to its high pH (12-13). Caustic liquids cause coagulative necrosis that results in substantial tissue damage. Due to the caustic nature of the solution it is expected that there would be toxic effects (e.g. edema) to the respiratory system if mists or vapors are inhaled and toxic effects for skin and eye exposures, especially at elevated temperatures. The toxicity ranking above is associated with representative components of the black liquor (sodium sulfide and sodium hydroxide, etc.) which are presented as a determination of acute toxicity of the complex mixture by analogy.

Prevention

Wear gloves, clothing, eye, face and respiratory protection. Avoid breathing mist or vapors. Use only outdoors or in a well-ventilated area. Contaminated clothing should not be taken out of the workplace. Avoid release to the environment.

Response

If in eyes rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do, continue rinsing. If eye irritation persists get medical attention. If swallowed, rinse mouth. If swallowed or inhaled immediately call a poison center or doctor/physician and remove victim to fresh air and keep at rest in a position comfortable for breathing. If on skin wash with plenty of water. Take off immediately all contaminated clothing. Rinse skin with water/shower, continue rinsing. Wash contaminated clothing before reuse. If skin irritation or rash occurs, get medical advice/attention. Wash hands after handling.

Disposal

Dispose of in accordance with Federal, state and local regulations Ingredients of Unknown Acute Toxicity (>1%): Not applicable. CAUTION: Caustic process liquors, may under certain conditions of reaction, produce total reduced sulfur gases (TRS) including hydrogen sulfide (H2S); methyl mercaptan (MM), dimethyl sulfide (DMS) and dimethyl disulfide (DMDS). These four gases may be formed by reaction at varying concentrations depending on environmental conditions (acidification, heating, etc.) as well as the location within the process where gases are generated (digestion vs. evaporation, etc.). These gases are hazardous (H2S being the most toxic for acute short term exposures). The concentration of the gases will also vary depending on whether the liquor is a strong or weak liquor but are typically below 1%. Potential exposures must be evaluated in process areas where emissions from reaction are likely and during line break and confined space entry in vessels and piping which have contained liquors. Although the sulfide content of black liquors are high, the sulfide gas concentrations are very low at the normal pH levels of these liquors. Unless the liquor is acidified to pH < 10, free H2S concentrations would be very low. The DMS and DMDS are not pH dependent and will exert some vapor pressure; even at the high pH of liquor.