Chemical Safety in Laboratories

Study Notes

Immediate eye irrigation is essential for chemical splashes.
Hazard Communication Standard mandates evaluation and communication of health hazards for all produced chemicals.
Use gloves and rubberized sleeves for protection against caustic chemicals.
Laboratory coats should have liquid-resistant material, full length, and proper cuff design.
Closed-toe footwear is mandatory to protect against spills.
Respirators may be necessary for specific procedures; training and maintenance are required.
Hand washing is critical for infection control and hygiene in chemical handling.

Flammable/Combustible Chemicals: Examples include acetone and toluene.
Corrosive Chemicals: Examples include nitric acid and hydrochloric acid; can cause severe injury to skin or eyes.
Reactive Chemicals: Examples such as peroxides that may spontaneously ignite or explode under specific conditions.
Carcinogenic Chemicals: Examples include benzidine, which is known to cause cancer.

Only use explosion-rated equipment in hazardous environments.
Ensure high-voltage equipment is properly grounded and inspect for frayed cords.
Machine malfunctions should be reported immediately; avoid working on “live” electrical systems.
Operate electrical machines with dry hands and be aware of electrical control panels.

Implement a radiation safety policy focusing on protection for the environment and personnel.
Areas with radioactive materials must display caution signs, with restricted access.
Regular evaluation of radiation monitors is necessary to monitor exposure levels.

Sample variables include physiological factors, patient preparation, and collection challenges that can lead to preanalytical errors.
Physiological variations affecting results can include gender, age, and medical conditions.
Fasting is often required prior to specimen collection, typically overnight for 8 hours.
Laboratories must define procedures for specimen collection, transporting, processing, and error documentation.

To minimize preanalytical errors, analyze specimens quickly; CLSI recommends processing within 30 minutes.
Order of Draw for blood collection:
- Yellow Top: Blood Culture
- Light Blue Top: Citrate
- Red Top: Serum
- Green Top: Heparin
- Lavender Top: EDTA
- Gray Top: Sodium Fluoride/Potassium Oxalate

Analytical considerations include staff competence, assay selection and validation, internal quality control, and external quality assessments.
Quality control measures are vital to minimize errors in the analytical phase of testing.
Variations in laboratory methods may produce differences in reported results or normal ranges, requiring verification of reference ranges.

Accuracy in transcription and filing of results is critical.
Lab report content and format impacts clarity and understanding.
Timeliness in communicating critical values is essential for effective patient care.

All nonzero digits in measurements are significant.
Beer-Lambert law relates concentration and absorbance, providing a formula: A = abc, where A is absorbance, a is the absorptivity constant, b is the light path length, and c is the concentration.
The pH scale, ranging from 0 to 14, represents the hydrogen ion concentration with lower values indicating higher acidity.

pH indicates the negative logarithm of hydrogen ion concentration.
Mathematically expressed as pH = -log[H+], facilitating the measurement of acidity in solutions.