This document discusses industrial hygiene and toxicology. It begins by defining toxicology as the study of how toxicants enter and affect the body and how they are eliminated. Industrial hygiene aims to prevent or reduce exposure to toxicants. The key aspects of an industrial hygiene study are: hazard identification through tools like safety data sheets; hazard evaluation including monitoring exposures and comparing to standards; and hazard control through methods like engineering and administrative controls. Laws and regulations in Malaysia and the US govern industrial hygiene through agencies like OSHA, NIOSH, EPA and process for developing and enforcing regulations.

1. TOXICOLOGY:
INDUSTRIAL HYGIENE
(IH)
Ir Dr Jegalakshimi Jewaratnam
jegalaxmi24@um.edu.my
May 2021

2. TOXICOLOGY IS THE STUDY OF:
 How toxicants enter the organism
 How toxicants effect the organism
 How toxicants are eliminated from (leave) the
organism
Methods to prevent or reduce the entry of toxicants
into biological organisms is covered in industrial
hygiene.

3. ENVIRONMENTAL HEALTH PARADIGM
Exposure Assessment
Emission Sources  Environmental
Concentrations
Effects Assessment 
Internal Dose  Human Exposure

Health Effects

4. WHAT IS IH?
 Typical projects involving industrial hygiene to ensure
that workers are not exposed to harmful levels are
 monitoring toxic airborne vapor concentrations,
 reducing toxic airborne vapors through the use of ventilation,
 selecting proper personal protective equipment to prevent
worker exposure,
 developing procedures for the handling of hazardous
materials,
 monitoring and reducing noise, heat, radiation, and other
physical factors

5. WHAT IS IH?
 The three phases in any industrial hygiene project
are identification, evaluation, and control:
 Identification: determination of the presence or
possibility of workplace exposures.
 Evaluation: determination of the magnitude of the
exposure.
 Control: application of appropriate technology to reduce
workplace exposures to acceptable levels

6. HAZARD IDENTIFICATION
 Determining the potential for hazards to result in an
accident (risk assessment) is the identification step.
 Resources for evaluating the hazards and
developing control methods are allocated on a
priority basis, giving the appropriate time and
attention to the most significant hazards.
 Safety Data Sheets (SDS) is one of the most
important references used during an industrial
hygiene study involving toxic chemicals.

7. HAZARD IDENTIFICATION
https://www.hsa.ie/eng/Publications_and_Forms/Publications/Information_Sheets/SDS_hazchem_info_sheet.pdf

8. HAZARD EVALUATION
 The evaluation phase determines the extent and
degree of employee exposure to toxicants and
physical hazards in the workplace environment.
 During the evaluation study, the likelihood of large
and small leaks must be considered.
 Sudden exposures to high concentrations, through
large leaks, may lead to immediate acute effects.
such as unconsciousness, burning eyes, or fits of
coughing. The effect is rarely permanent.
 Chronic effects, arise from repeated exposures to low
concentrations, mostly by small leaks which might not
become obvious for months or even years. There
may be permanent and serious impairments from
such exposures.

9. HAZARD EVALUATION
 Continuous evaluation that is, continuous or
frequent and periodic sampling and analysis is
important.
 To establish the effectiveness of existing controls,
samples are taken to determine the workers'
exposure to conditions that may be harmful.
 If problems are evident, controls must be
implemented immediately; temporary controls such
as personal protective equipment can be used.
 Longer term and permanent controls are
subsequently developed.

10. HAZARD EVALUATION
 After the exposure data are obtained, it is
necessary to compare actual exposure levels to
acceptable occupational health standards, such as
TLVs, PELS, or IDLH concentrations.
 These standards together with the actual
concentrations are used to identify the potential
hazards requiring better or more control measures.

11. TLV, PEL & IDLH
Lowest value on the response versus dose curve is
called the threshold dose.
American Conference of Governmental Industrial
Hygienists (ACGIH) has established
“Threshold Limit Values” (TLV)
United States Occupational Safety and Health
Administration (OSHA) has established
“Permissible Exposure Limits” (PEL)
 US National Institute for Occupational Safety and Health
(NIOSH) has established
Immediately Dangerous to Life or Health (IDLH)
is defined by the as exposure to airborne contaminants
that is "likely to cause death or immediate or delayed
permanent adverse health effects or prevent escape from
such an environment.

12. TLV-THRESHOLD LIMIT VALUES
TLVTWA
Time weighted average for a normal 8 hour workday or 40
hour workweek
TLVSTEL Short-term exposure limit.
The maximum concentration can be exposed to for up to
15 minutes. Four excursions per day with at least 60
minutes between exposure is permissible.
TLVC Ceiling limit.
This concentration should not be exceeded

13. EVALUATING EXPOSURES TO VOLATILE
TOXICANTS BY MONITORING
 For continuous monitoring
 For periodic monitoring

15. HAZARD CONTROL
TABLE 3-9: CHEMICAL PLANT CONTROL TECHNIQUES

16. LAW AND REGULATION
 Laws and regulations are major tools for protecting
people and the environment.
 Laws often do not include the details for compliance.
 To make the laws work on a day-today level,
governmental organizations, namely EPA and OSHA,
create regulations and standards.
 Regulations set specific rules about what is legal and
what is not legal.
 A regulation relevant to the Clean Air Act will specify
levels of specific toxic chemicals that are safe, quantities
of the toxic chemicals that are legally emitted into the
air, and what penalties are given if the legal limits are
exceeded.
 After the regulation is in effect, the EPA has the
responsibility (1) to help citizens comply with the law
and (2) to enforce the regulation.

17. OSHA AND NIOSH
 OSHAct of 1970 was developed to give a nationally consistent
program with the funding necessary to manage it effectively.
 This act defined clear procedures for establishing regulations,
conducting investigations for compliance, and developing and
maintaining safety and health records.
 As a result of the OSH Act, sufficient funding was committed to
create and support the Occupational Safety and Health
Administration (OSHA), which manages and administers the
government's responsibilities specified in the OSH Act, and
the National Institute for Occupational Safety and Health
(NIOSH), which conducts research and technical assistance
programs for improving the protection and maintenance of
workers' health.

18. OSHA AND NIOSH
 NIOSH responsibilities include (1) measuring health
effects of exposure in the work environment, (2)
developing criteria for handling toxic materials, (3)
establishing safe levels of exposure, and (4)
training professionals for administering the
programs of the act.
 NIOSH develops data and information regarding
hazards, and OSHA uses these data to
promulgate standards.

19. PSM & RMP
 Process safety management (PSM) by OSHA and
Risk Management Plan (RMP) by EPA were
developed after the Bhopal accident (1985), to
prevent similar accidents.
 It is recognized by industry and the government as
excellent regulations that will reduce the number
and magnitude of accidents if it is understood and
practiced as intended.

20. PSM & RMP
 The PSM standard has 14 major sections: employee
participation, process safety information, process hazard
analysis, operating procedures, training, contractors, pre-
startup safety review, mechanical integrity, hot work
permits, management of change, incident investigations,
emergency planning and response, audits, and trade
secrets.
 The RMP standard has 4 major elements:
hazard assessment, prevention program, emergency
response program, documentation that is maintained on the
site and submitted to federal, state, and local authorities and
share info to local communities.

21. PSM & RMP
 RMP is similar to the PSM regulation in many aspects
 RMP is designed to protect off-site people and the environment,
whereas PSM is designed to protect on-site people.
 The RMP is a site responsibility (the site may have several
processes), whereas PSM covers every covered process on the
site.

22. ASSIGNMENT:
Question 1 and 2:

23. ASSIGNMENT
 3. How is the law and regulation for IH is
endorsed in Malaysia?
 4. What are the acts that govern industrial
hygiene (IH) in Malaysia?
 5. After the law is official, how is it put into
practice? Please state the responsible entities and
its function in Malaysia.
For Question 2 to 4, you may refer to textbook which
states American practice. Please state what is
practice in Malaysia for industrial hygiene/toxicology.

24. TO DO LIST
 Pls submit Assignment on 6th June 2021
 Look into examples from references e-book pages
101 to 116
OR
Refer to the example slides in spectrum
 You may read Chapter 3 of the reference book for
additional info
END