Wood preservation facilities, inorganic boron (borate): chapter I-6

6. Protection of Personnel

For general comments, and for recommendations on precautions and personal hygiene measures on personnel exposure and protection, refer to Part I - Chapter A, Section 6. All comments and recommendations in that section are applicable to borate wood preservation facilities.

6.1 First Aid Precautions and Hygiene for Borate Exposure

The general rule for dealing with exposure is as follows: the higher the concentration of a preservative to which a worker is exposed, the greater the need for protective measures and immediate response if contact occurs. If there is any doubt as to the concentration, the response should be the same as for the most concentrated form.

Facility staff should have access to product labels and appropriate training to apply first aid.

Artificial respiration should not be performed without the use of a barrier device, as the injured person may be contaminated (on skin) with boron solution, making the first aider the next victim if direct mouth-to-mouth contact is made.

Disodium octaborate tetrahydrate is not considered an acute poison. See Section 4 - Human Health Concerns.

Table 5 details the first aid measures for different type of exposure to Borate. First and second actions are described to provide hierarchic step by step actions.

For all medical attention, always take the pesticide label to show to the health personnel.

6.2 Regulatory Controls

The label for pesticide products contains information on the minimum necessary protective equipment and practices for using the product. The worker protection measures on the pesticide label are mandatory. Provincial or municipal regulations may require additional measures that may enhance, but not reduce, protection. Table 7 in Chapter A can be used to summarize the local regulatory threshold limit values (TLVs) and/or biological exposure indices (BEIs) applicable to the plant.

Specific limits for worker protection are generally prescribed by provincial regulations. Consult your local authorities for specific applicable regulations.

Skin and Eye Contact

There is no suggested “biological exposure indices” (BEI) that are developed for boron by the American Conference of Governmental Industrial Hygienists (ACGIH).

Inhalation

Most regulatory criteria established by worker protection agencies are based on TLVs and BEIs recommended by the ACGIH (18)

The ACGIH has defined TLVs for many substances based on exposure by inhalation and/or skin exposure. The ACGIH limits for Boron are based solely on exposure by inhalation. The TLVs are stipulated by the ACGIH as those “airborne concentrations of substances to which it is believed that nearly all workers may be repeatedly exposed day after day without adverse effects.” The ACGIH-recommended limits for Inorganic Borate compounds and Boron oxide.

ACGIH refers to disodium octaborate tetrahydrate (DOT) as a “particulate not otherwise classified” or “nuisance dust” and are summarized in Table 4.0 above with the following provisos of the ACGIH:

• “The limits are intended for use in the practice of industrial hygiene as guidelines for good practices or recommendations in the control of potential health hazards and for no other use” (i.e. proof or disproof of the cause of an existing disease or physical condition).
• “The limits are not fine lines between safe and dangerous concentrations.”
• “In spite of the fact that serious injury is not believed likely as a result of exposure to the Threshold Limit concentrations, the best practice is to maintain concentrations of all atmospheric contaminants as low as is practical.”
• “When two or more hazardous substances, which act upon the same organ system, are present, their combined effect, rather than that of either individually, should be given primary consideration.”

Ingestion

Oral intake of Boron must be avoided. Ingestion of liquids containing Boron is unlikely if workers follow the safety precautions outlined in Table 8 from Chapter A. Upper limits of ingestion are not prescribed by regulation, because it is generally expected that no such intake will occur.

6.3 Safety Precautions

Workers need to familiarize themselves with the safety precautions mentioned in Chapter A, Section 6.3. Sensitive individuals should take special care to avoid exposure.

Boron compounds are currently under re-evaluation at the PMRA. The safety precautions outlined on the pesticide labels must be followed.

6.4 Biological Monitoring of Exposed Workers

Although boron is not acutely toxic, workers can have different sensitivity tolerance to it. Biological monitoring can be a useful tool for evaluating the health of workers and the long-term effectiveness of the protective measures applied. Routine biological monitoring of exposed workers (primarily those who handle preservatives and treated wood, e.g., plant operators and quality control personnel) is recommended. Refer to Chapter A, Section 6.4