757 Laboratory Safety

Ricin Toxin

Ricin is produced in maturing seeds of the castor bean, Ricinus communis, which has been recognized for centuries as a highly poisonous plant for humans and livestock. Ricin belongs to a family of ribosome inactivating proteins from plants, including abrin, modeccin, and viscumin, that share a similar overall structure and mechanism of action.

Gastric ingestion of ricin causes nausea, vomiting, diarrhea, abdominal cramps and dehydration. Initial symptoms may appear more rapidly following gastric ingestion (1-5 h), but generally require exposure to much higher levels of toxin compared with the inhalation route.

Ricin is a relatively non-specific cytotoxin and irritant that should be handled in the laboratory as a non-volatile toxic chemical. A BSC (Class II, Type B1 or B2) or a chemical fume hood equipped with an exhaust HEPA filter and charcoal filter are indicated for activities with a high potential for aerosol, such as powder samples, and the use of large quantities of toxin. Laboratory coat, gloves, and full-face respirator should be worn if there is a potential for creating a toxin aerosol.

For more information on Ricin, see OSHA's Ricin Webpage.

Severe Acute Respiratory Syndrome (SARS)

SARS is a severe viral illness that was first reported in Asia in February 2003. The illness is characterized by a variety of symptoms including fever, cough, and shortness of breath. In a minority of patients (6-9%), SARS may even progress to death. SARS has been reported in North America among persons returning from travel to Asia, among health care workers, and among others in contact with individuals with SARS. Because new outbreaks may occur, laboratory employees should be aware of the recommended measures to prevent occupational SARS infection.

SARS is spread primarily by close contact with a SARS patient or contact with respiratory secretions/body fluids from a SARS patient. Transmission from contaminated objects has been reported. The incubation period is typically between two and seven days.

SARS presentation is typical of a respiratory viral illness. Patients usually present with a high fever (>100.4 F), cough, chills and headache. Most will progress to develop pneumonia and some will even require mechanical ventilation.

Work procedures to prevent the spread of disease include frequent hand cleansing and avoiding direct contact with body fluids of SARS patients. Personal protective equipment (PPE) is appropriate in healthcare facilities and certain occupational settings, such as airline clean-up, when SARS infection is a known risk. Staff should not sort soiled linens suspected of SARS contamination at the point of use. Laundering soiled linens in warm water and detergent has been advised. Compressed air should not be used for cleaning areas where SARS patients or their body fluids are present.

Engineering Controls include use of airborne isolation rooms or negative air pressure environments for aerosol generating procedures (e.g. sputum induction in SARS patients) and handling laboratory specimens in biological safety cabinets.

For more information on SARS-CoV-2( causes COVID-19) see OSHA's Coronavirus Disease (COVID-19) website.

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